diff --git a/Cargo.lock b/Cargo.lock
index 602bb3eab..65786b266 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -14,9 +14,9 @@ dependencies = [
  "environment",
  "eth2",
  "eth2_keystore",
+ "eth2_network_config",
  "eth2_ssz",
  "eth2_ssz_derive",
- "eth2_testnet_config",
  "eth2_wallet",
  "eth2_wallet_manager",
  "futures 0.3.8",
@@ -592,8 +592,8 @@ dependencies = [
  "environment",
  "eth2_config",
  "eth2_libp2p",
+ "eth2_network_config",
  "eth2_ssz",
- "eth2_testnet_config",
  "exit-future",
  "futures 0.3.8",
  "genesis",
@@ -816,8 +816,8 @@ dependencies = [
  "beacon_node",
  "clap",
  "eth2_libp2p",
+ "eth2_network_config",
  "eth2_ssz",
- "eth2_testnet_config",
  "futures 0.3.8",
  "hex",
  "log 0.4.11",
@@ -1048,8 +1048,8 @@ version = "0.1.0"
 dependencies = [
  "clap",
  "dirs 3.0.1",
+ "eth2_network_config",
  "eth2_ssz",
- "eth2_testnet_config",
  "hex",
  "types",
 ]
@@ -1604,7 +1604,7 @@ dependencies = [
  "clap",
  "clap_utils",
  "dirs 3.0.1",
- "eth2_testnet_config",
+ "eth2_network_config",
 ]
 
 [[package]]
@@ -1851,7 +1851,7 @@ version = "0.1.2"
 dependencies = [
  "ctrlc",
  "eth2_config",
- "eth2_testnet_config",
+ "eth2_network_config",
  "exit-future",
  "futures 0.3.8",
  "logging",
@@ -2062,6 +2062,20 @@ dependencies = [
  "void",
 ]
 
+[[package]]
+name = "eth2_network_config"
+version = "0.2.0"
+dependencies = [
+ "enr",
+ "eth2_config",
+ "eth2_ssz",
+ "serde",
+ "serde_yaml",
+ "tempdir",
+ "types",
+ "zip",
+]
+
 [[package]]
 name = "eth2_ssz"
 version = "0.1.2"
@@ -2094,20 +2108,6 @@ dependencies = [
  "typenum",
 ]
 
-[[package]]
-name = "eth2_testnet_config"
-version = "0.2.0"
-dependencies = [
- "enr",
- "eth2_config",
- "eth2_ssz",
- "serde",
- "serde_yaml",
- "tempdir",
- "types",
- "zip",
-]
-
 [[package]]
 name = "eth2_wallet"
 version = "0.1.0"
@@ -3483,8 +3483,8 @@ dependencies = [
  "environment",
  "eth2_keystore",
  "eth2_libp2p",
+ "eth2_network_config",
  "eth2_ssz",
- "eth2_testnet_config",
  "futures 0.3.8",
  "genesis",
  "hex",
@@ -3877,7 +3877,7 @@ dependencies = [
  "directory",
  "env_logger 0.8.2",
  "environment",
- "eth2_testnet_config",
+ "eth2_network_config",
  "futures 0.3.8",
  "lighthouse_version",
  "logging",
diff --git a/Cargo.toml b/Cargo.toml
index ec7b055b9..95f59c493 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,7 +24,7 @@ members = [
     "common/eth2",
     "common/eth2_config",
     "common/eth2_interop_keypairs",
-    "common/eth2_testnet_config",
+    "common/eth2_network_config",
     "common/eth2_wallet_manager",
     "common/hashset_delay",
     "common/lighthouse_metrics",
diff --git a/account_manager/Cargo.toml b/account_manager/Cargo.toml
index fece15a78..e2ed1b95e 100644
--- a/account_manager/Cargo.toml
+++ b/account_manager/Cargo.toml
@@ -19,7 +19,7 @@ eth2_ssz = "0.1.2"
 eth2_ssz_derive = "0.1.0"
 hex = "0.4.2"
 rayon = "1.4.1"
-eth2_testnet_config = { path = "../common/eth2_testnet_config" }
+eth2_network_config = { path = "../common/eth2_network_config" }
 futures = { version = "0.3.7", features = ["compat"] }
 clap_utils = { path = "../common/clap_utils" }
 directory = { path = "../common/directory" }
diff --git a/account_manager/src/validator/exit.rs b/account_manager/src/validator/exit.rs
index 3cf8900af..2f88eed69 100644
--- a/account_manager/src/validator/exit.rs
+++ b/account_manager/src/validator/exit.rs
@@ -7,7 +7,7 @@ use eth2::{
     BeaconNodeHttpClient, Url,
 };
 use eth2_keystore::Keystore;
-use eth2_testnet_config::Eth2TestnetConfig;
+use eth2_network_config::Eth2NetworkConfig;
 use safe_arith::SafeArith;
 use slot_clock::{SlotClock, SystemTimeSlotClock};
 use std::path::PathBuf;
@@ -99,7 +99,7 @@ async fn publish_voluntary_exit<E: EthSpec>(
     client: &BeaconNodeHttpClient,
     spec: &ChainSpec,
     stdin_inputs: bool,
-    testnet_config: &Eth2TestnetConfig,
+    testnet_config: &Eth2NetworkConfig,
 ) -> Result<(), String> {
     let genesis_data = get_geneisis_data(client).await?;
     let testnet_genesis_root = testnet_config
diff --git a/beacon_node/Cargo.toml b/beacon_node/Cargo.toml
index 8a2b41a9d..d13a26b15 100644
--- a/beacon_node/Cargo.toml
+++ b/beacon_node/Cargo.toml
@@ -36,7 +36,7 @@ futures = "0.3.7"
 environment = { path = "../lighthouse/environment" }
 task_executor = { path = "../common/task_executor" }
 genesis = { path = "genesis" }
-eth2_testnet_config = { path = "../common/eth2_testnet_config" }
+eth2_network_config = { path = "../common/eth2_network_config" }
 eth2_libp2p = { path = "./eth2_libp2p" }
 eth2_ssz = "0.1.2"
 serde = "1.0.116"
diff --git a/beacon_node/eth2_libp2p/src/config.rs b/beacon_node/eth2_libp2p/src/config.rs
index f9ce72059..017366652 100644
--- a/beacon_node/eth2_libp2p/src/config.rs
+++ b/beacon_node/eth2_libp2p/src/config.rs
@@ -1,7 +1,7 @@
 use crate::types::{GossipKind, MessageData};
 use crate::{Enr, PeerIdSerialized};
 use directory::{
-    DEFAULT_BEACON_NODE_DIR, DEFAULT_HARDCODED_TESTNET, DEFAULT_NETWORK_DIR, DEFAULT_ROOT_DIR,
+    DEFAULT_BEACON_NODE_DIR, DEFAULT_HARDCODED_NETWORK, DEFAULT_NETWORK_DIR, DEFAULT_ROOT_DIR,
 };
 use discv5::{Discv5Config, Discv5ConfigBuilder};
 use libp2p::gossipsub::{
@@ -104,7 +104,7 @@ impl Default for Config {
         let network_dir = dirs::home_dir()
             .unwrap_or_else(|| PathBuf::from("."))
             .join(DEFAULT_ROOT_DIR)
-            .join(DEFAULT_HARDCODED_TESTNET)
+            .join(DEFAULT_HARDCODED_NETWORK)
             .join(DEFAULT_BEACON_NODE_DIR)
             .join(DEFAULT_NETWORK_DIR);
 
diff --git a/beacon_node/src/config.rs b/beacon_node/src/config.rs
index d70ab8e46..38e752498 100644
--- a/beacon_node/src/config.rs
+++ b/beacon_node/src/config.rs
@@ -4,7 +4,7 @@ use clap_utils::BAD_TESTNET_DIR_MESSAGE;
 use client::{ClientConfig, ClientGenesis};
 use directory::{DEFAULT_BEACON_NODE_DIR, DEFAULT_NETWORK_DIR, DEFAULT_ROOT_DIR};
 use eth2_libp2p::{multiaddr::Protocol, Enr, Multiaddr, NetworkConfig, PeerIdSerialized};
-use eth2_testnet_config::Eth2TestnetConfig;
+use eth2_network_config::{Eth2NetworkConfig, DEFAULT_HARDCODED_NETWORK};
 use slog::{info, warn, Logger};
 use std::cmp;
 use std::cmp::max;
@@ -237,13 +237,13 @@ pub fn get_config<E: EthSpec>(
     }
 
     /*
-     * Load the eth2 testnet dir to obtain some additional config values.
+     * Load the eth2 network dir to obtain some additional config values.
      */
-    let eth2_testnet_config = get_eth2_testnet_config(&cli_args)?;
+    let eth2_network_config = get_eth2_network_config(&cli_args)?;
 
     client_config.eth1.deposit_contract_address = format!("{:?}", spec.deposit_contract_address);
     client_config.eth1.deposit_contract_deploy_block =
-        eth2_testnet_config.deposit_contract_deploy_block;
+        eth2_network_config.deposit_contract_deploy_block;
     client_config.eth1.lowest_cached_block_number =
         client_config.eth1.deposit_contract_deploy_block;
     client_config.eth1.follow_distance = spec.eth1_follow_distance;
@@ -260,11 +260,11 @@ pub fn get_config<E: EthSpec>(
         "address" => &client_config.eth1.deposit_contract_address
     );
 
-    if let Some(mut boot_nodes) = eth2_testnet_config.boot_enr {
+    if let Some(mut boot_nodes) = eth2_network_config.boot_enr {
         client_config.network.boot_nodes_enr.append(&mut boot_nodes)
     }
 
-    if let Some(genesis_state_bytes) = eth2_testnet_config.genesis_state_bytes {
+    if let Some(genesis_state_bytes) = eth2_network_config.genesis_state_bytes {
         // Note: re-serializing the genesis state is not so efficient, however it avoids adding
         // trait bounds to the `ClientGenesis` enum. This would have significant flow-on
         // effects.
@@ -578,26 +578,25 @@ pub fn get_data_dir(cli_args: &ArgMatches) -> PathBuf {
         .or_else(|| {
             dirs::home_dir().map(|home| {
                 home.join(DEFAULT_ROOT_DIR)
-                    .join(directory::get_testnet_name(cli_args))
+                    .join(directory::get_network_dir(cli_args))
                     .join(DEFAULT_BEACON_NODE_DIR)
             })
         })
         .unwrap_or_else(|| PathBuf::from("."))
 }
 
-/// Try to parse the eth2 testnet config from the `network`, `testnet-dir` flags in that order.
+/// Try to parse the eth2 network config from the `network`, `testnet-dir` flags in that order.
 /// Returns the default hardcoded testnet if neither flags are set.
-pub fn get_eth2_testnet_config(cli_args: &ArgMatches) -> Result<Eth2TestnetConfig, String> {
-    let optional_testnet_config = if cli_args.is_present("network") {
+pub fn get_eth2_network_config(cli_args: &ArgMatches) -> Result<Eth2NetworkConfig, String> {
+    let optional_network_config = if cli_args.is_present("network") {
         clap_utils::parse_hardcoded_network(cli_args, "network")?
     } else if cli_args.is_present("testnet-dir") {
         clap_utils::parse_testnet_dir(cli_args, "testnet-dir")?
     } else {
-        return Err(
-            "No --network or --testnet-dir flags provided, cannot load config.".to_string(),
-        );
+        // if neither is present, assume the default network
+        Eth2NetworkConfig::constant(DEFAULT_HARDCODED_NETWORK)?
     };
-    optional_testnet_config.ok_or_else(|| BAD_TESTNET_DIR_MESSAGE.to_string())
+    optional_network_config.ok_or_else(|| BAD_TESTNET_DIR_MESSAGE.to_string())
 }
 
 /// A bit of hack to find an unused port.
diff --git a/beacon_node/src/lib.rs b/beacon_node/src/lib.rs
index a5dc2f07b..7671c15ea 100644
--- a/beacon_node/src/lib.rs
+++ b/beacon_node/src/lib.rs
@@ -12,7 +12,7 @@ use beacon_chain::{
 use clap::ArgMatches;
 pub use cli::cli_app;
 pub use client::{Client, ClientBuilder, ClientConfig, ClientGenesis};
-pub use config::{get_config, get_data_dir, get_eth2_testnet_config, set_network_config};
+pub use config::{get_config, get_data_dir, get_eth2_network_config, set_network_config};
 use environment::RuntimeContext;
 pub use eth2_config::Eth2Config;
 use slasher::Slasher;
diff --git a/boot_node/Cargo.toml b/boot_node/Cargo.toml
index 1ff3327c3..4e7578d21 100644
--- a/boot_node/Cargo.toml
+++ b/boot_node/Cargo.toml
@@ -7,9 +7,9 @@ edition = "2018"
 [dependencies]
 beacon_node = { path = "../beacon_node" }
 clap = "2.33.3"
-eth2_libp2p = { path = "../beacon_node/eth2_libp2p" } 
-types = { path = "../consensus/types" } 
-eth2_testnet_config = { path = "../common/eth2_testnet_config" } 
+eth2_libp2p = { path = "../beacon_node/eth2_libp2p" }
+types = { path = "../consensus/types" }
+eth2_network_config = { path = "../common/eth2_network_config" }
 eth2_ssz = "0.1.2"
 slog = "2.5.2"
 sloggers = "1.0.1"
diff --git a/boot_node/src/config.rs b/boot_node/src/config.rs
index 212fdd17f..c66c24c63 100644
--- a/boot_node/src/config.rs
+++ b/boot_node/src/config.rs
@@ -1,4 +1,4 @@
-use beacon_node::{get_data_dir, get_eth2_testnet_config, set_network_config};
+use beacon_node::{get_data_dir, get_eth2_network_config, set_network_config};
 use clap::ArgMatches;
 use eth2_libp2p::discv5::{enr::CombinedKey, Enr};
 use eth2_libp2p::{
@@ -28,24 +28,16 @@ impl<T: EthSpec> TryFrom<&ArgMatches<'_>> for BootNodeConfig<T> {
     fn try_from(matches: &ArgMatches<'_>) -> Result<Self, Self::Error> {
         let data_dir = get_data_dir(matches);
 
-        // Try and grab testnet config from input CLI params
-        let eth2_testnet_config = {
-            if matches.is_present("network") {
-                Some(get_eth2_testnet_config(&matches)?)
-            } else {
-                None
-            }
-        };
+        // Try and grab network config from input CLI params
+        let eth2_network_config = get_eth2_network_config(&matches)?;
 
         // Try and obtain bootnodes
 
         let boot_nodes = {
             let mut boot_nodes = Vec::new();
 
-            if let Some(testnet_config) = eth2_testnet_config.as_ref() {
-                if let Some(enr) = &testnet_config.boot_enr {
-                    boot_nodes.extend_from_slice(enr);
-                }
+            if let Some(enr) = &eth2_network_config.boot_enr {
+                boot_nodes.extend_from_slice(enr);
             }
 
             if let Some(nodes) = matches.value_of("boot-nodes") {
@@ -80,16 +72,16 @@ impl<T: EthSpec> TryFrom<&ArgMatches<'_>> for BootNodeConfig<T> {
         let local_key = CombinedKey::from_libp2p(&private_key)?;
 
         // build the enr_fork_id and add it to the local_enr if it exists
-        let enr_fork = if let Some(config) = eth2_testnet_config.as_ref() {
-            let spec = config
+        let enr_fork = {
+            let spec = eth2_network_config
                 .yaml_config
                 .as_ref()
-                .ok_or("The testnet directory must contain a spec config")?
+                .ok_or("The network directory must contain a spec config")?
                 .apply_to_chain_spec::<T>(&T::default_spec())
                 .ok_or("The loaded config is not compatible with the current spec")?;
 
-            if config.beacon_state_is_known() {
-                let genesis_state = config.beacon_state::<T>()?;
+            if eth2_network_config.beacon_state_is_known() {
+                let genesis_state = eth2_network_config.beacon_state::<T>()?;
 
                 slog::info!(logger, "Genesis state found"; "root" => genesis_state.canonical_root().to_string());
                 let enr_fork = spec.enr_fork_id(
@@ -105,12 +97,6 @@ impl<T: EthSpec> TryFrom<&ArgMatches<'_>> for BootNodeConfig<T> {
                 );
                 None
             }
-        } else {
-            slog::warn!(
-                logger,
-                "No testnet config provided. Not setting an eth2 field"
-            );
-            None
         };
 
         // Build the local ENR
diff --git a/common/clap_utils/Cargo.toml b/common/clap_utils/Cargo.toml
index 85c562a50..561691715 100644
--- a/common/clap_utils/Cargo.toml
+++ b/common/clap_utils/Cargo.toml
@@ -11,5 +11,5 @@ clap = "2.33.3"
 hex = "0.4.2"
 dirs = "3.0.1"
 types = { path = "../../consensus/types" }
-eth2_testnet_config = { path = "../eth2_testnet_config" }
+eth2_network_config = { path = "../eth2_network_config" }
 eth2_ssz = "0.1.2"
diff --git a/common/clap_utils/src/lib.rs b/common/clap_utils/src/lib.rs
index e78401b81..2d43a1b28 100644
--- a/common/clap_utils/src/lib.rs
+++ b/common/clap_utils/src/lib.rs
@@ -1,7 +1,7 @@
 //! A helper library for parsing values from `clap::ArgMatches`.
 
 use clap::ArgMatches;
-use eth2_testnet_config::Eth2TestnetConfig;
+use eth2_network_config::Eth2NetworkConfig;
 use ssz::Decode;
 use std::path::PathBuf;
 use std::str::FromStr;
@@ -16,9 +16,9 @@ pub const BAD_TESTNET_DIR_MESSAGE: &str = "The hard-coded testnet directory was
 pub fn parse_testnet_dir(
     matches: &ArgMatches,
     name: &'static str,
-) -> Result<Option<Eth2TestnetConfig>, String> {
+) -> Result<Option<Eth2NetworkConfig>, String> {
     let path = parse_required::<PathBuf>(matches, name)?;
-    Eth2TestnetConfig::load(path.clone())
+    Eth2NetworkConfig::load(path.clone())
         .map_err(|e| format!("Unable to open testnet dir at {:?}: {}", path, e))
         .map(Some)
 }
@@ -28,9 +28,9 @@ pub fn parse_testnet_dir(
 pub fn parse_hardcoded_network(
     matches: &ArgMatches,
     name: &str,
-) -> Result<Option<Eth2TestnetConfig>, String> {
+) -> Result<Option<Eth2NetworkConfig>, String> {
     let network_name = parse_required::<String>(matches, name)?;
-    Eth2TestnetConfig::constant(network_name.as_str())
+    Eth2NetworkConfig::constant(network_name.as_str())
 }
 
 /// If `name` is in `matches`, parses the value as a path. Otherwise, attempts to find the user's
diff --git a/common/directory/Cargo.toml b/common/directory/Cargo.toml
index 1687bb48b..116f20894 100644
--- a/common/directory/Cargo.toml
+++ b/common/directory/Cargo.toml
@@ -10,4 +10,4 @@ edition = "2018"
 clap = "2.33.3"
 clap_utils = {path = "../clap_utils"}
 dirs = "3.0.1"
-eth2_testnet_config = { path = "../eth2_testnet_config" }
+eth2_network_config = { path = "../eth2_network_config" }
diff --git a/common/directory/src/lib.rs b/common/directory/src/lib.rs
index 9e45dc8c6..aeb781d7a 100644
--- a/common/directory/src/lib.rs
+++ b/common/directory/src/lib.rs
@@ -1,5 +1,5 @@
 use clap::ArgMatches;
-pub use eth2_testnet_config::DEFAULT_HARDCODED_TESTNET;
+pub use eth2_network_config::DEFAULT_HARDCODED_NETWORK;
 use std::fs::{self, create_dir_all};
 use std::path::{Path, PathBuf};
 
@@ -19,13 +19,13 @@ pub const CUSTOM_TESTNET_DIR: &str = "custom";
 /// Tries to get the name first from the "network" flag,
 /// if not present, then checks the "testnet-dir" flag and returns a custom name
 /// If neither flags are present, returns the default hardcoded network name.
-pub fn get_testnet_name(matches: &ArgMatches) -> String {
-    if let Some(testnet_name) = matches.value_of("network") {
-        testnet_name.to_string()
+pub fn get_network_dir(matches: &ArgMatches) -> String {
+    if let Some(network_name) = matches.value_of("network") {
+        network_name.to_string()
     } else if matches.value_of("testnet-dir").is_some() {
         CUSTOM_TESTNET_DIR.to_string()
     } else {
-        eth2_testnet_config::DEFAULT_HARDCODED_TESTNET.to_string()
+        eth2_network_config::DEFAULT_HARDCODED_NETWORK.to_string()
     }
 }
 
@@ -54,7 +54,7 @@ pub fn parse_path_or_default_with_flag(
         arg,
         PathBuf::new()
             .join(DEFAULT_ROOT_DIR)
-            .join(get_testnet_name(matches))
+            .join(get_network_dir(matches))
             .join(flag),
     )
 }
diff --git a/common/eth2_config/src/lib.rs b/common/eth2_config/src/lib.rs
index 7ad2a8fe9..442df63a1 100644
--- a/common/eth2_config/src/lib.rs
+++ b/common/eth2_config/src/lib.rs
@@ -5,13 +5,13 @@ use types::{ChainSpec, EthSpecId};
 
 // A macro is used to define this constant so it can be used with `include_bytes!`.
 #[macro_export]
-macro_rules! testnets_dir {
+macro_rules! predefined_networks_dir {
     () => {
-        "built_in_testnet_configs"
+        "built_in_network_configs"
     };
 }
 
-pub const TESTNETS_DIR: &str = testnets_dir!();
+pub const PREDEFINED_NETWORKS_DIR: &str = predefined_networks_dir!();
 pub const GENESIS_FILE_NAME: &str = "genesis.ssz";
 pub const GENESIS_ZIP_FILE_NAME: &str = "genesis.ssz.zip";
 
@@ -57,7 +57,7 @@ impl Eth2Config {
 
 /// A directory that can be built by downloading files via HTTP.
 ///
-/// Used by the `eth2_testnet_config` crate to initialize testnet directories during build and
+/// Used by the `eth2_network_config` crate to initialize the network directories during build and
 /// access them at runtime.
 #[derive(Copy, Clone, Debug, PartialEq)]
 pub struct Eth2NetArchiveAndDirectory<'a> {
@@ -73,7 +73,7 @@ impl<'a> Eth2NetArchiveAndDirectory<'a> {
             .expect("should know manifest dir")
             .parse::<PathBuf>()
             .expect("should parse manifest dir as path")
-            .join(TESTNETS_DIR)
+            .join(PREDEFINED_NETWORKS_DIR)
             .join(self.unique_id)
     }
 
@@ -94,7 +94,7 @@ macro_rules! define_net {
                 genesis_is_known: $genesis_is_known,
             };
 
-            // A wrapper around `std::include_bytes` which includes a file from a specific testnet
+            // A wrapper around `std::include_bytes` which includes a file from a specific network
             // directory. Used by upstream crates to import files at compile time.
             #[macro_export]
             macro_rules! $macro_title {
@@ -102,7 +102,7 @@ macro_rules! define_net {
                     include_bytes!(concat!(
                         $base_dir,
                         "/",
-                        testnets_dir!(),
+                        predefined_networks_dir!(),
                         "/",
                         $name,
                         "/",
diff --git a/common/eth2_testnet_config/.gitignore b/common/eth2_network_config/.gitignore
similarity index 100%
rename from common/eth2_testnet_config/.gitignore
rename to common/eth2_network_config/.gitignore
diff --git a/common/eth2_testnet_config/Cargo.toml b/common/eth2_network_config/Cargo.toml
similarity index 93%
rename from common/eth2_testnet_config/Cargo.toml
rename to common/eth2_network_config/Cargo.toml
index e54f3ff17..f853ac5ce 100644
--- a/common/eth2_testnet_config/Cargo.toml
+++ b/common/eth2_network_config/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "eth2_testnet_config"
+name = "eth2_network_config"
 version = "0.2.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = "2018"
diff --git a/common/eth2_testnet_config/build.rs b/common/eth2_network_config/build.rs
similarity index 76%
rename from common/eth2_testnet_config/build.rs
rename to common/eth2_network_config/build.rs
index 697f63a2b..f6a07171f 100644
--- a/common/eth2_testnet_config/build.rs
+++ b/common/eth2_network_config/build.rs
@@ -1,4 +1,4 @@
-//! Downloads a testnet configuration from Github.
+//! Downloads a network configuration from Github.
 
 use eth2_config::{
     altona, mainnet, medalla, pyrmont, spadina, toledo, Eth2NetArchiveAndDirectory,
@@ -18,21 +18,21 @@ const ETH2_NET_DIRS: &[Eth2NetArchiveAndDirectory<'static>] = &[
 ];
 
 fn main() {
-    for testnet in ETH2_NET_DIRS {
-        match uncompress_state(testnet) {
+    for network in ETH2_NET_DIRS {
+        match uncompress_state(network) {
             Ok(()) => (),
             Err(e) => panic!(
                 "Failed to uncompress {} genesis state zip file: {}",
-                testnet.name, e
+                network.name, e
             ),
         }
     }
 }
 
-/// Uncompress the testnet configs archive into a testnet configs folder.
-fn uncompress_state(testnet: &Eth2NetArchiveAndDirectory<'static>) -> Result<(), String> {
-    if testnet.genesis_is_known {
-        let archive_path = testnet.genesis_state_archive();
+/// Uncompress the network configs archive into a network configs folder.
+fn uncompress_state(network: &Eth2NetArchiveAndDirectory<'static>) -> Result<(), String> {
+    if network.genesis_is_known {
+        let archive_path = network.genesis_state_archive();
         let archive_file = File::open(&archive_path)
             .map_err(|e| format!("Failed to open archive file {:?}: {:?}", archive_path, e))?;
 
@@ -45,14 +45,14 @@ fn uncompress_state(testnet: &Eth2NetArchiveAndDirectory<'static>) -> Result<(),
                 GENESIS_FILE_NAME, e
             )
         })?;
-        let path = testnet.dir().join(GENESIS_FILE_NAME);
+        let path = network.dir().join(GENESIS_FILE_NAME);
         let mut outfile = File::create(&path)
             .map_err(|e| format!("Error while creating file {:?}: {}", path, e))?;
         io::copy(&mut file, &mut outfile)
             .map_err(|e| format!("Error writing file {:?}: {}", path, e))?;
     } else {
         // Create empty genesis.ssz if genesis is unknown
-        let genesis_file = testnet.dir().join(GENESIS_FILE_NAME);
+        let genesis_file = network.dir().join(GENESIS_FILE_NAME);
         if !genesis_file.exists() {
             File::create(genesis_file)
                 .map_err(|e| format!("Failed to create {}: {}", GENESIS_FILE_NAME, e))?;
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/boot_enr.yaml b/common/eth2_network_config/built_in_network_configs/altona/boot_enr.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/altona/boot_enr.yaml
rename to common/eth2_network_config/built_in_network_configs/altona/boot_enr.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/config.yaml b/common/eth2_network_config/built_in_network_configs/altona/config.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/altona/config.yaml
rename to common/eth2_network_config/built_in_network_configs/altona/config.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/deploy_block.txt b/common/eth2_network_config/built_in_network_configs/altona/deploy_block.txt
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/altona/deploy_block.txt
rename to common/eth2_network_config/built_in_network_configs/altona/deploy_block.txt
diff --git a/common/eth2_network_config/built_in_network_configs/altona/genesis.ssz b/common/eth2_network_config/built_in_network_configs/altona/genesis.ssz
new file mode 100644
index 000000000..7a91759df
Binary files /dev/null and b/common/eth2_network_config/built_in_network_configs/altona/genesis.ssz differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/genesis.ssz.zip b/common/eth2_network_config/built_in_network_configs/altona/genesis.ssz.zip
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/altona/genesis.ssz.zip
rename to common/eth2_network_config/built_in_network_configs/altona/genesis.ssz.zip
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/mainnet/boot_enr.yaml b/common/eth2_network_config/built_in_network_configs/mainnet/boot_enr.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/mainnet/boot_enr.yaml
rename to common/eth2_network_config/built_in_network_configs/mainnet/boot_enr.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/mainnet/config.yaml b/common/eth2_network_config/built_in_network_configs/mainnet/config.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/mainnet/config.yaml
rename to common/eth2_network_config/built_in_network_configs/mainnet/config.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/mainnet/deploy_block.txt b/common/eth2_network_config/built_in_network_configs/mainnet/deploy_block.txt
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/mainnet/deploy_block.txt
rename to common/eth2_network_config/built_in_network_configs/mainnet/deploy_block.txt
diff --git a/common/eth2_network_config/built_in_network_configs/mainnet/genesis.ssz b/common/eth2_network_config/built_in_network_configs/mainnet/genesis.ssz
new file mode 100644
index 000000000..f68d0e967
Binary files /dev/null and b/common/eth2_network_config/built_in_network_configs/mainnet/genesis.ssz differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/mainnet/genesis.ssz.zip b/common/eth2_network_config/built_in_network_configs/mainnet/genesis.ssz.zip
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/mainnet/genesis.ssz.zip
rename to common/eth2_network_config/built_in_network_configs/mainnet/genesis.ssz.zip
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/boot_enr.yaml b/common/eth2_network_config/built_in_network_configs/medalla/boot_enr.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/medalla/boot_enr.yaml
rename to common/eth2_network_config/built_in_network_configs/medalla/boot_enr.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/config.yaml b/common/eth2_network_config/built_in_network_configs/medalla/config.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/medalla/config.yaml
rename to common/eth2_network_config/built_in_network_configs/medalla/config.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/deploy_block.txt b/common/eth2_network_config/built_in_network_configs/medalla/deploy_block.txt
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/medalla/deploy_block.txt
rename to common/eth2_network_config/built_in_network_configs/medalla/deploy_block.txt
diff --git a/common/eth2_network_config/built_in_network_configs/medalla/genesis.ssz b/common/eth2_network_config/built_in_network_configs/medalla/genesis.ssz
new file mode 100644
index 000000000..6691c8992
Binary files /dev/null and b/common/eth2_network_config/built_in_network_configs/medalla/genesis.ssz differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/genesis.ssz.zip b/common/eth2_network_config/built_in_network_configs/medalla/genesis.ssz.zip
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/medalla/genesis.ssz.zip
rename to common/eth2_network_config/built_in_network_configs/medalla/genesis.ssz.zip
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/pyrmont/boot_enr.yaml b/common/eth2_network_config/built_in_network_configs/pyrmont/boot_enr.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/pyrmont/boot_enr.yaml
rename to common/eth2_network_config/built_in_network_configs/pyrmont/boot_enr.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/pyrmont/config.yaml b/common/eth2_network_config/built_in_network_configs/pyrmont/config.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/pyrmont/config.yaml
rename to common/eth2_network_config/built_in_network_configs/pyrmont/config.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/pyrmont/deploy_block.txt b/common/eth2_network_config/built_in_network_configs/pyrmont/deploy_block.txt
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/pyrmont/deploy_block.txt
rename to common/eth2_network_config/built_in_network_configs/pyrmont/deploy_block.txt
diff --git a/common/eth2_network_config/built_in_network_configs/pyrmont/genesis.ssz b/common/eth2_network_config/built_in_network_configs/pyrmont/genesis.ssz
new file mode 100644
index 000000000..c566d7e04
Binary files /dev/null and b/common/eth2_network_config/built_in_network_configs/pyrmont/genesis.ssz differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/pyrmont/genesis.ssz.zip b/common/eth2_network_config/built_in_network_configs/pyrmont/genesis.ssz.zip
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/pyrmont/genesis.ssz.zip
rename to common/eth2_network_config/built_in_network_configs/pyrmont/genesis.ssz.zip
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/boot_enr.yaml b/common/eth2_network_config/built_in_network_configs/spadina/boot_enr.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/spadina/boot_enr.yaml
rename to common/eth2_network_config/built_in_network_configs/spadina/boot_enr.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/config.yaml b/common/eth2_network_config/built_in_network_configs/spadina/config.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/spadina/config.yaml
rename to common/eth2_network_config/built_in_network_configs/spadina/config.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/deploy_block.txt b/common/eth2_network_config/built_in_network_configs/spadina/deploy_block.txt
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/spadina/deploy_block.txt
rename to common/eth2_network_config/built_in_network_configs/spadina/deploy_block.txt
diff --git a/common/eth2_network_config/built_in_network_configs/spadina/genesis.ssz b/common/eth2_network_config/built_in_network_configs/spadina/genesis.ssz
new file mode 100644
index 000000000..ccc90a001
Binary files /dev/null and b/common/eth2_network_config/built_in_network_configs/spadina/genesis.ssz differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/genesis.ssz.zip b/common/eth2_network_config/built_in_network_configs/spadina/genesis.ssz.zip
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/spadina/genesis.ssz.zip
rename to common/eth2_network_config/built_in_network_configs/spadina/genesis.ssz.zip
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/toledo/boot_enr.yaml b/common/eth2_network_config/built_in_network_configs/toledo/boot_enr.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/toledo/boot_enr.yaml
rename to common/eth2_network_config/built_in_network_configs/toledo/boot_enr.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/toledo/config.yaml b/common/eth2_network_config/built_in_network_configs/toledo/config.yaml
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/toledo/config.yaml
rename to common/eth2_network_config/built_in_network_configs/toledo/config.yaml
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/toledo/deploy_block.txt b/common/eth2_network_config/built_in_network_configs/toledo/deploy_block.txt
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/toledo/deploy_block.txt
rename to common/eth2_network_config/built_in_network_configs/toledo/deploy_block.txt
diff --git a/common/eth2_network_config/built_in_network_configs/toledo/genesis.ssz b/common/eth2_network_config/built_in_network_configs/toledo/genesis.ssz
new file mode 100644
index 000000000..a5b588a9f
Binary files /dev/null and b/common/eth2_network_config/built_in_network_configs/toledo/genesis.ssz differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/toledo/genesis.ssz.zip b/common/eth2_network_config/built_in_network_configs/toledo/genesis.ssz.zip
similarity index 100%
rename from common/eth2_testnet_config/built_in_testnet_configs/toledo/genesis.ssz.zip
rename to common/eth2_network_config/built_in_network_configs/toledo/genesis.ssz.zip
diff --git a/common/eth2_network_config/built_in_network_configs/zinken/genesis.ssz b/common/eth2_network_config/built_in_network_configs/zinken/genesis.ssz
new file mode 100644
index 000000000..f645a7f24
Binary files /dev/null and b/common/eth2_network_config/built_in_network_configs/zinken/genesis.ssz differ
diff --git a/common/eth2_testnet_config/src/lib.rs b/common/eth2_network_config/src/lib.rs
similarity index 93%
rename from common/eth2_testnet_config/src/lib.rs
rename to common/eth2_network_config/src/lib.rs
index fc0c1404e..c3e1e6db2 100644
--- a/common/eth2_testnet_config/src/lib.rs
+++ b/common/eth2_network_config/src/lib.rs
@@ -1,13 +1,4 @@
-//! This crate should eventually represent the structure at this repo:
-//!
-//! https://github.com/eth2-clients/eth2-testnets/tree/master/nimbus/testnet1
-//!
-//! It is not accurate at the moment, we include extra files and we also don't support a few
-//! others. We are unable to conform to the repo until we have the following PR merged:
-//!
-//! https://github.com/sigp/lighthouse/pull/605
-//!
-use eth2_config::{testnets_dir, *};
+use eth2_config::{predefined_networks_dir, *};
 
 use enr::{CombinedKey, Enr};
 use ssz::Decode;
@@ -55,13 +46,13 @@ const MAINNET: HardcodedNet = define_net!(mainnet, include_mainnet_file);
 const TOLEDO: HardcodedNet = define_net!(toledo, include_toledo_file);
 
 const HARDCODED_NETS: &[HardcodedNet] = &[ALTONA, MEDALLA, SPADINA, PYRMONT, MAINNET, TOLEDO];
-pub const DEFAULT_HARDCODED_TESTNET: &str = "mainnet";
+pub const DEFAULT_HARDCODED_NETWORK: &str = "mainnet";
 
-/// Specifies an Eth2 testnet.
+/// Specifies an Eth2 network.
 ///
 /// See the crate-level documentation for more details.
 #[derive(Clone, PartialEq, Debug)]
-pub struct Eth2TestnetConfig {
+pub struct Eth2NetworkConfig {
     /// Note: instead of the block where the contract is deployed, it is acceptable to set this
     /// value to be the block number where the first deposit occurs.
     pub deposit_contract_deploy_block: u64,
@@ -70,7 +61,7 @@ pub struct Eth2TestnetConfig {
     pub yaml_config: Option<YamlConfig>,
 }
 
-impl Eth2TestnetConfig {
+impl Eth2NetworkConfig {
     /// When Lighthouse is built it includes zero or more "hardcoded" network specifications. This
     /// function allows for instantiating one of these nets by name.
     pub fn constant(name: &str) -> Result<Option<Self>, String> {
@@ -100,7 +91,7 @@ impl Eth2TestnetConfig {
     }
 
     /// Returns an identifier that should be used for selecting an `EthSpec` instance for this
-    /// testnet.
+    /// network configuration.
     pub fn eth_spec_id(&self) -> Result<EthSpecId, String> {
         self.yaml_config
             .as_ref()
@@ -133,7 +124,7 @@ impl Eth2TestnetConfig {
     /// Overwrites files if specified to do so.
     pub fn write_to_file(&self, base_dir: PathBuf, overwrite: bool) -> Result<(), String> {
         if base_dir.exists() && !overwrite {
-            return Err("Testnet directory already exists".to_string());
+            return Err("Network directory already exists".to_string());
         }
 
         self.force_write_to_file(base_dir)
@@ -257,7 +248,7 @@ mod tests {
     fn hard_coded_nets_work() {
         for net in HARDCODED_NETS {
             let config =
-                Eth2TestnetConfig::from_hardcoded_net(net).expect(&format!("{:?}", net.name));
+                Eth2NetworkConfig::from_hardcoded_net(net).expect(&format!("{:?}", net.name));
 
             if net.name == "mainnet" || net.name == "toledo" || net.name == "pyrmont" {
                 // Ensure we can parse the YAML config to a chain spec.
@@ -314,7 +305,7 @@ mod tests {
         let base_dir = temp_dir.path().join("my_testnet");
         let deposit_contract_deploy_block = 42;
 
-        let testnet: Eth2TestnetConfig = Eth2TestnetConfig {
+        let testnet: Eth2NetworkConfig = Eth2NetworkConfig {
             deposit_contract_deploy_block,
             boot_enr,
             genesis_state_bytes: genesis_state.as_ref().map(Encode::as_ssz_bytes),
@@ -325,7 +316,7 @@ mod tests {
             .write_to_file(base_dir.clone(), false)
             .expect("should write to file");
 
-        let decoded = Eth2TestnetConfig::load(base_dir).expect("should load struct");
+        let decoded = Eth2NetworkConfig::load(base_dir).expect("should load struct");
 
         assert_eq!(testnet, decoded, "should decode as encoded");
     }
diff --git a/lcli/Cargo.toml b/lcli/Cargo.toml
index eb98d6dcf..7b021ddb1 100644
--- a/lcli/Cargo.toml
+++ b/lcli/Cargo.toml
@@ -23,7 +23,7 @@ regex = "1.3.9"
 futures = { version = "0.3.7", features = ["compat"] }
 environment = { path = "../lighthouse/environment" }
 web3 = "0.11.0"
-eth2_testnet_config = { path = "../common/eth2_testnet_config" }
+eth2_network_config = { path = "../common/eth2_network_config" }
 dirs = "3.0.1"
 genesis = { path = "../beacon_node/genesis" }
 deposit_contract = { path = "../common/deposit_contract" }
diff --git a/lcli/src/eth1_genesis.rs b/lcli/src/eth1_genesis.rs
index 97aefe560..7b91d1141 100644
--- a/lcli/src/eth1_genesis.rs
+++ b/lcli/src/eth1_genesis.rs
@@ -1,6 +1,6 @@
 use clap::ArgMatches;
 use environment::Environment;
-use eth2_testnet_config::Eth2TestnetConfig;
+use eth2_network_config::Eth2NetworkConfig;
 use genesis::{Eth1Config, Eth1GenesisService};
 use ssz::Encode;
 use std::cmp::max;
@@ -32,9 +32,9 @@ pub fn run<T: EthSpec>(mut env: Environment<T>, matches: &ArgMatches<'_>) -> Res
                 .expect("should locate home directory")
         });
 
-    let mut eth2_testnet_config = Eth2TestnetConfig::load(testnet_dir.clone())?;
+    let mut eth2_network_config = Eth2NetworkConfig::load(testnet_dir.clone())?;
 
-    let spec = eth2_testnet_config
+    let spec = eth2_network_config
         .yaml_config
         .as_ref()
         .ok_or("The testnet directory must contain a spec config")?
@@ -51,8 +51,8 @@ pub fn run<T: EthSpec>(mut env: Environment<T>, matches: &ArgMatches<'_>) -> Res
         config.endpoints = v;
     }
     config.deposit_contract_address = format!("{:?}", spec.deposit_contract_address);
-    config.deposit_contract_deploy_block = eth2_testnet_config.deposit_contract_deploy_block;
-    config.lowest_cached_block_number = eth2_testnet_config.deposit_contract_deploy_block;
+    config.deposit_contract_deploy_block = eth2_network_config.deposit_contract_deploy_block;
+    config.lowest_cached_block_number = eth2_network_config.deposit_contract_deploy_block;
     config.follow_distance = spec.eth1_follow_distance / 2;
     config.node_far_behind_seconds = max(5, config.follow_distance) * spec.seconds_per_eth1_block;
 
@@ -65,8 +65,8 @@ pub fn run<T: EthSpec>(mut env: Environment<T>, matches: &ArgMatches<'_>) -> Res
                 .wait_for_genesis_state::<T>(ETH1_GENESIS_UPDATE_INTERVAL, spec)
                 .await
                 .map(move |genesis_state| {
-                    eth2_testnet_config.genesis_state_bytes = Some(genesis_state.as_ssz_bytes());
-                    eth2_testnet_config.force_write_to_file(testnet_dir)
+                    eth2_network_config.genesis_state_bytes = Some(genesis_state.as_ssz_bytes());
+                    eth2_network_config.force_write_to_file(testnet_dir)
                 })
                 .map_err(|e| format!("Failed to find genesis: {}", e))?;
 
diff --git a/lcli/src/interop_genesis.rs b/lcli/src/interop_genesis.rs
index 4aed06b3d..744dd4447 100644
--- a/lcli/src/interop_genesis.rs
+++ b/lcli/src/interop_genesis.rs
@@ -1,7 +1,7 @@
 use clap::ArgMatches;
 use clap_utils::parse_ssz_optional;
 use environment::Environment;
-use eth2_testnet_config::Eth2TestnetConfig;
+use eth2_network_config::Eth2NetworkConfig;
 use genesis::interop_genesis_state;
 use ssz::Encode;
 use std::path::PathBuf;
@@ -36,9 +36,9 @@ pub fn run<T: EthSpec>(mut env: Environment<T>, matches: &ArgMatches) -> Result<
                 .expect("should locate home directory")
         });
 
-    let mut eth2_testnet_config = Eth2TestnetConfig::load(testnet_dir.clone())?;
+    let mut eth2_network_config = Eth2NetworkConfig::load(testnet_dir.clone())?;
 
-    let mut spec = eth2_testnet_config
+    let mut spec = eth2_network_config
         .yaml_config
         .as_ref()
         .ok_or("The testnet directory must contain a spec config")?
@@ -57,8 +57,8 @@ pub fn run<T: EthSpec>(mut env: Environment<T>, matches: &ArgMatches) -> Result<
     let keypairs = generate_deterministic_keypairs(validator_count);
     let genesis_state = interop_genesis_state::<T>(&keypairs, genesis_time, &spec)?;
 
-    eth2_testnet_config.genesis_state_bytes = Some(genesis_state.as_ssz_bytes());
-    eth2_testnet_config.force_write_to_file(testnet_dir)?;
+    eth2_network_config.genesis_state_bytes = Some(genesis_state.as_ssz_bytes());
+    eth2_network_config.force_write_to_file(testnet_dir)?;
 
     Ok(())
 }
diff --git a/lcli/src/new_testnet.rs b/lcli/src/new_testnet.rs
index de1aeb9cf..e45cc368c 100644
--- a/lcli/src/new_testnet.rs
+++ b/lcli/src/new_testnet.rs
@@ -2,7 +2,7 @@ use clap::ArgMatches;
 use clap_utils::{
     parse_optional, parse_path_with_default_in_home_dir, parse_required, parse_ssz_optional,
 };
-use eth2_testnet_config::Eth2TestnetConfig;
+use eth2_network_config::Eth2NetworkConfig;
 use std::path::PathBuf;
 use types::{Address, EthSpec, YamlConfig};
 
@@ -53,7 +53,7 @@ pub fn run<T: EthSpec>(matches: &ArgMatches) -> Result<(), String> {
         spec.genesis_fork_version = v;
     }
 
-    let testnet = Eth2TestnetConfig {
+    let testnet = Eth2NetworkConfig {
         deposit_contract_deploy_block,
         boot_enr: Some(vec![]),
         genesis_state_bytes: None,
diff --git a/lighthouse/Cargo.toml b/lighthouse/Cargo.toml
index 3c1c4c4b0..50a491f69 100644
--- a/lighthouse/Cargo.toml
+++ b/lighthouse/Cargo.toml
@@ -32,7 +32,7 @@ futures = "0.3.7"
 validator_client = { "path" = "../validator_client" }
 account_manager = { "path" = "../account_manager" }
 clap_utils = { path = "../common/clap_utils" }
-eth2_testnet_config = { path = "../common/eth2_testnet_config" }
+eth2_network_config = { path = "../common/eth2_network_config" }
 directory = { path = "../common/directory" }
 lighthouse_version = { path = "../common/lighthouse_version" }
 account_utils = { path = "../common/account_utils" }
diff --git a/lighthouse/environment/Cargo.toml b/lighthouse/environment/Cargo.toml
index 832505807..9260b9cfd 100644
--- a/lighthouse/environment/Cargo.toml
+++ b/lighthouse/environment/Cargo.toml
@@ -11,7 +11,7 @@ sloggers = "1.0.1"
 types = { "path" = "../../consensus/types" }
 eth2_config = { "path" = "../../common/eth2_config" }
 task_executor = { "path" = "../../common/task_executor" }
-eth2_testnet_config = { path = "../../common/eth2_testnet_config" }
+eth2_network_config = { path = "../../common/eth2_network_config" }
 logging = { path = "../../common/logging" }
 slog-term = "2.6.0"
 slog-async = "2.5.0"
diff --git a/lighthouse/environment/src/lib.rs b/lighthouse/environment/src/lib.rs
index f892d2b61..fee7369ac 100644
--- a/lighthouse/environment/src/lib.rs
+++ b/lighthouse/environment/src/lib.rs
@@ -8,7 +8,7 @@
 //! logging.
 
 use eth2_config::Eth2Config;
-use eth2_testnet_config::Eth2TestnetConfig;
+use eth2_network_config::Eth2NetworkConfig;
 use futures::channel::{
     mpsc::{channel, Receiver, Sender},
     oneshot,
@@ -38,7 +38,7 @@ pub struct EnvironmentBuilder<E: EthSpec> {
     log: Option<Logger>,
     eth_spec_instance: E,
     eth2_config: Eth2Config,
-    testnet: Option<Eth2TestnetConfig>,
+    testnet: Option<Eth2NetworkConfig>,
 }
 
 impl EnvironmentBuilder<MinimalEthSpec> {
@@ -221,12 +221,12 @@ impl<E: EthSpec> EnvironmentBuilder<E> {
     }
 
     /// Adds a testnet configuration to the environment.
-    pub fn eth2_testnet_config(
+    pub fn eth2_network_config(
         mut self,
-        eth2_testnet_config: Eth2TestnetConfig,
+        eth2_network_config: Eth2NetworkConfig,
     ) -> Result<Self, String> {
         // Create a new chain spec from the default configuration.
-        self.eth2_config.spec = eth2_testnet_config
+        self.eth2_config.spec = eth2_network_config
             .yaml_config
             .as_ref()
             .ok_or("The testnet directory must contain a spec config")?
@@ -238,18 +238,18 @@ impl<E: EthSpec> EnvironmentBuilder<E> {
                 )
             })?;
 
-        self.testnet = Some(eth2_testnet_config);
+        self.testnet = Some(eth2_network_config);
 
         Ok(self)
     }
 
     /// Optionally adds a testnet configuration to the environment.
-    pub fn optional_eth2_testnet_config(
+    pub fn optional_eth2_network_config(
         self,
-        optional_config: Option<Eth2TestnetConfig>,
+        optional_config: Option<Eth2NetworkConfig>,
     ) -> Result<Self, String> {
         if let Some(config) = optional_config {
-            self.eth2_testnet_config(config)
+            self.eth2_network_config(config)
         } else {
             Ok(self)
         }
@@ -322,7 +322,7 @@ pub struct Environment<E: EthSpec> {
     log: Logger,
     eth_spec_instance: E,
     pub eth2_config: Eth2Config,
-    pub testnet: Option<Eth2TestnetConfig>,
+    pub testnet: Option<Eth2NetworkConfig>,
 }
 
 impl<E: EthSpec> Environment<E> {
diff --git a/lighthouse/environment/tests/environment_builder.rs b/lighthouse/environment/tests/environment_builder.rs
index 439da974d..ce03e686c 100644
--- a/lighthouse/environment/tests/environment_builder.rs
+++ b/lighthouse/environment/tests/environment_builder.rs
@@ -1,7 +1,7 @@
 #![cfg(test)]
 
 use environment::EnvironmentBuilder;
-use eth2_testnet_config::{Eth2TestnetConfig, DEFAULT_HARDCODED_TESTNET};
+use eth2_network_config::{Eth2NetworkConfig, DEFAULT_HARDCODED_NETWORK};
 use std::path::PathBuf;
 use types::{V012LegacyEthSpec, YamlConfig};
 
@@ -13,8 +13,8 @@ fn builder() -> EnvironmentBuilder<V012LegacyEthSpec> {
         .expect("should set logger")
 }
 
-fn eth2_testnet_config() -> Option<Eth2TestnetConfig> {
-    Eth2TestnetConfig::constant(DEFAULT_HARDCODED_TESTNET).expect("should decode mainnet params")
+fn eth2_network_config() -> Option<Eth2NetworkConfig> {
+    Eth2NetworkConfig::constant(DEFAULT_HARDCODED_NETWORK).expect("should decode mainnet params")
 }
 
 mod setup_eth2_config {
@@ -22,15 +22,15 @@ mod setup_eth2_config {
 
     #[test]
     fn update_spec_with_yaml_config() {
-        if let Some(mut eth2_testnet_config) = eth2_testnet_config() {
+        if let Some(mut eth2_network_config) = eth2_network_config() {
             let config_yaml = PathBuf::from("./tests/testnet_dir/config.yaml");
 
-            eth2_testnet_config.yaml_config = Some(
+            eth2_network_config.yaml_config = Some(
                 YamlConfig::from_file(config_yaml.as_path()).expect("should load yaml config"),
             );
 
             let environment = builder()
-                .eth2_testnet_config(eth2_testnet_config)
+                .eth2_network_config(eth2_network_config)
                 .expect("should setup eth2_config")
                 .build()
                 .expect("should build environment");
diff --git a/lighthouse/src/main.rs b/lighthouse/src/main.rs
index 251e25aea..b53ab43b1 100644
--- a/lighthouse/src/main.rs
+++ b/lighthouse/src/main.rs
@@ -1,8 +1,8 @@
-use beacon_node::ProductionBeaconNode;
+use beacon_node::{get_eth2_network_config, ProductionBeaconNode};
 use clap::{App, Arg, ArgMatches};
 use env_logger::{Builder, Env};
 use environment::EnvironmentBuilder;
-use eth2_testnet_config::{Eth2TestnetConfig, DEFAULT_HARDCODED_TESTNET};
+use eth2_network_config::{Eth2NetworkConfig, DEFAULT_HARDCODED_NETWORK};
 use lighthouse_version::VERSION;
 use slog::{crit, info, warn};
 use std::path::PathBuf;
@@ -118,7 +118,6 @@ fn main() {
                 .help("Name of the Eth2 chain Lighthouse will sync and follow.")
                 .possible_values(&["medalla", "altona", "spadina", "pyrmont", "mainnet", "toledo"])
                 .conflicts_with("testnet-dir")
-                .default_value(DEFAULT_HARDCODED_TESTNET)
                 .takes_value(true)
                 .global(true)
 
@@ -135,7 +134,7 @@ fn main() {
         Builder::from_env(Env::default()).init();
     }
 
-    let result = load_testnet_config(&matches).and_then(|testnet_config| {
+    let result = get_eth2_network_config(&matches).and_then(|testnet_config| {
         let eth_spec_id = testnet_config.eth_spec_id()?;
 
         // boot node subcommand circumvents the environment
@@ -174,22 +173,10 @@ fn main() {
     }
 }
 
-fn load_testnet_config(matches: &ArgMatches) -> Result<Eth2TestnetConfig, String> {
-    if matches.is_present("testnet-dir") {
-        clap_utils::parse_testnet_dir(matches, "testnet-dir")?
-            .ok_or_else(|| "Unable to load testnet dir".to_string())
-    } else if matches.is_present("network") {
-        clap_utils::parse_hardcoded_network(matches, "network")?
-            .ok_or_else(|| "Unable to load hard coded network config".to_string())
-    } else {
-        Err("No --network or --testnet-dir flags provided, cannot start.".to_string())
-    }
-}
-
 fn run<E: EthSpec>(
     environment_builder: EnvironmentBuilder<E>,
     matches: &ArgMatches,
-    testnet_config: Eth2TestnetConfig,
+    testnet_config: Eth2NetworkConfig,
 ) -> Result<(), String> {
     if std::mem::size_of::<usize>() != 8 {
         return Err(format!(
@@ -215,7 +202,7 @@ fn run<E: EthSpec>(
 
     let mut environment = builder
         .multi_threaded_tokio_runtime()?
-        .optional_eth2_testnet_config(Some(testnet_config))?
+        .optional_eth2_network_config(Some(testnet_config))?
         .build()?;
 
     let log = environment.core_context().log().clone();
@@ -248,15 +235,15 @@ fn run<E: EthSpec>(
     let optional_testnet = clap_utils::parse_optional::<String>(matches, "network")?;
     let optional_testnet_dir = clap_utils::parse_optional::<PathBuf>(matches, "testnet-dir")?;
 
-    let testnet_name = match (optional_testnet, optional_testnet_dir) {
+    let network_name = match (optional_testnet, optional_testnet_dir) {
         (Some(testnet), None) => testnet,
         (None, Some(testnet_dir)) => format!("custom ({})", testnet_dir.display()),
-        (None, None) => DEFAULT_HARDCODED_TESTNET.to_string(),
+        (None, None) => DEFAULT_HARDCODED_NETWORK.to_string(),
         (Some(_), Some(_)) => panic!("CLI prevents both --network and --testnet-dir"),
     };
 
     if let Some(sub_matches) = matches.subcommand_matches("account_manager") {
-        eprintln!("Running account manager for {} network", testnet_name);
+        eprintln!("Running account manager for {} network", network_name);
         // Pass the entire `environment` to the account manager so it can run blocking operations.
         account_manager::run(sub_matches, environment)?;
 
@@ -268,7 +255,7 @@ fn run<E: EthSpec>(
     info!(
         log,
         "Configured for network";
-        "name" => &testnet_name
+        "name" => &network_name
     );
 
     match matches.subcommand() {
diff --git a/validator_client/src/config.rs b/validator_client/src/config.rs
index c43a02929..fcba726ad 100644
--- a/validator_client/src/config.rs
+++ b/validator_client/src/config.rs
@@ -2,7 +2,7 @@ use crate::{http_api, http_metrics};
 use clap::ArgMatches;
 use clap_utils::{parse_optional, parse_required};
 use directory::{
-    get_testnet_name, DEFAULT_HARDCODED_TESTNET, DEFAULT_ROOT_DIR, DEFAULT_SECRET_DIR,
+    get_network_dir, DEFAULT_HARDCODED_NETWORK, DEFAULT_ROOT_DIR, DEFAULT_SECRET_DIR,
     DEFAULT_VALIDATOR_DIR,
 };
 use eth2::types::Graffiti;
@@ -44,12 +44,12 @@ pub struct Config {
 impl Default for Config {
     /// Build a new configuration from defaults.
     fn default() -> Self {
-        // WARNING: these directory defaults should be always overrided with parameters
-        // from cli for specific networks.
+        // WARNING: these directory defaults should be always overwritten with parameters from cli
+        // for specific networks.
         let base_dir = dirs::home_dir()
             .unwrap_or_else(|| PathBuf::from("."))
             .join(DEFAULT_ROOT_DIR)
-            .join(DEFAULT_HARDCODED_TESTNET);
+            .join(DEFAULT_HARDCODED_NETWORK);
         let validator_dir = base_dir.join(DEFAULT_VALIDATOR_DIR);
         let secrets_dir = base_dir.join(DEFAULT_SECRET_DIR);
         Self {
@@ -91,13 +91,13 @@ impl Config {
 
         config.validator_dir = validator_dir.unwrap_or_else(|| {
             default_root_dir
-                .join(get_testnet_name(cli_args))
+                .join(get_network_dir(cli_args))
                 .join(DEFAULT_VALIDATOR_DIR)
         });
 
         config.secrets_dir = secrets_dir.unwrap_or_else(|| {
             default_root_dir
-                .join(get_testnet_name(cli_args))
+                .join(get_network_dir(cli_args))
                 .join(DEFAULT_SECRET_DIR)
         });