diff --git a/beacon_node/src/config.rs b/beacon_node/src/config.rs
index 070c99734..83757fc7c 100644
--- a/beacon_node/src/config.rs
+++ b/beacon_node/src/config.rs
@@ -270,6 +270,7 @@ pub fn get_config<E: EthSpec>(
     client_config.eth1.lowest_cached_block_number =
         client_config.eth1.deposit_contract_deploy_block;
     client_config.eth1.follow_distance = spec.eth1_follow_distance;
+    client_config.eth1.network_id = spec.deposit_network_id.into();
 
     if let Some(mut boot_nodes) = eth2_testnet_config.boot_enr {
         client_config.network.boot_nodes_enr.append(&mut boot_nodes)
diff --git a/common/eth2_config/src/lib.rs b/common/eth2_config/src/lib.rs
index 31258a2ad..598aadbe1 100644
--- a/common/eth2_config/src/lib.rs
+++ b/common/eth2_config/src/lib.rs
@@ -3,6 +3,18 @@ use std::env;
 use std::path::PathBuf;
 use types::ChainSpec;
 
+// A macro is used to define this constant so it can be used with `include_bytes!`.
+#[macro_export]
+macro_rules! testnets_dir {
+    () => {
+        "built_in_testnet_configs"
+    };
+}
+
+pub const TESTNETS_DIR: &str = testnets_dir!();
+pub const GENESIS_FILE_NAME: &str = "genesis.ssz";
+pub const GENESIS_ZIP_FILE_NAME: &str = "genesis.ssz.zip";
+
 /// The core configuration of a Lighthouse beacon node.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(default)]
@@ -51,33 +63,23 @@ impl Eth2Config {
 pub struct Eth2NetArchiveAndDirectory<'a> {
     pub name: &'a str,
     pub unique_id: &'a str,
-    pub archive_name: &'a str,
     pub genesis_is_known: bool,
 }
 
 impl<'a> Eth2NetArchiveAndDirectory<'a> {
     /// The directory that should be used to store files downloaded for this net.
-    fn pwd(&self) -> PathBuf {
+    pub fn dir(&self) -> PathBuf {
         env::var("CARGO_MANIFEST_DIR")
             .expect("should know manifest dir")
             .parse::<PathBuf>()
             .expect("should parse manifest dir as path")
+            .join(TESTNETS_DIR)
+            .join(self.unique_id)
     }
 
-    pub fn dir(&self) -> PathBuf {
-        self.pwd().join(self.unique_id)
+    pub fn genesis_state_archive(&self) -> PathBuf {
+        self.dir().join(GENESIS_ZIP_FILE_NAME)
     }
-
-    pub fn archive_fullpath(&self) -> PathBuf {
-        self.pwd().join(self.archive_name)
-    }
-}
-
-#[macro_export]
-macro_rules! unique_id {
-    ($name: tt) => {
-        concat!("testnet_", $name);
-    };
 }
 
 macro_rules! define_net {
@@ -88,8 +90,7 @@ macro_rules! define_net {
 
             pub const ETH2_NET_DIR: Eth2NetArchiveAndDirectory = Eth2NetArchiveAndDirectory {
                 name: $name,
-                unique_id: unique_id!($name),
-                archive_name: concat!(unique_id!($name), ".zip"),
+                unique_id: $name,
                 genesis_is_known: $genesis_is_known,
             };
 
@@ -98,7 +99,15 @@ macro_rules! define_net {
             #[macro_export]
             macro_rules! $macro_title {
                 ($base_dir: tt, $filename: tt) => {
-                    include_bytes!(concat!($base_dir, unique_id!($name), "/", $filename))
+                    include_bytes!(concat!(
+                        $base_dir,
+                        "/",
+                        testnets_dir!(),
+                        "/",
+                        $name,
+                        "/",
+                        $filename
+                    ))
                 };
             }
         }
diff --git a/common/eth2_testnet_config/.gitignore b/common/eth2_testnet_config/.gitignore
index eddff8082..9cf78e1ae 100644
--- a/common/eth2_testnet_config/.gitignore
+++ b/common/eth2_testnet_config/.gitignore
@@ -1,4 +1,5 @@
 testnet*/*
 schlesi-*
 witti-*
-altona*
+/altona*
+built_in_testnet_configs/*/genesis.ssz
diff --git a/common/eth2_testnet_config/build.rs b/common/eth2_testnet_config/build.rs
index e9f4794d4..073422ace 100644
--- a/common/eth2_testnet_config/build.rs
+++ b/common/eth2_testnet_config/build.rs
@@ -1,7 +1,8 @@
 //! Downloads a testnet configuration from Github.
 
-use eth2_config::{altona, medalla, spadina, zinken, Eth2NetArchiveAndDirectory};
-use std::fs;
+use eth2_config::{
+    altona, medalla, spadina, zinken, Eth2NetArchiveAndDirectory, GENESIS_FILE_NAME,
+};
 use std::fs::File;
 use std::io;
 use zip::ZipArchive;
@@ -15,42 +16,41 @@ const ETH2_NET_DIRS: &[Eth2NetArchiveAndDirectory<'static>] = &[
 
 fn main() {
     for testnet in ETH2_NET_DIRS {
-        match uncompress(testnet) {
+        match uncompress_state(testnet) {
             Ok(()) => (),
-            Err(e) => panic!("Failed to uncompress testnet zip file: {}", e),
+            Err(e) => panic!(
+                "Failed to uncompress {} genesis state zip file: {}",
+                testnet.name, e
+            ),
         }
     }
 }
 
 /// Uncompress the testnet configs archive into a testnet configs folder.
-fn uncompress(testnet: &Eth2NetArchiveAndDirectory<'static>) -> Result<(), String> {
-    let archive_file = File::open(&testnet.archive_fullpath())
-        .map_err(|e| format!("Failed to open archive file: {:?}", e))?;
+fn uncompress_state(testnet: &Eth2NetArchiveAndDirectory<'static>) -> Result<(), String> {
+    let archive_path = testnet.genesis_state_archive();
+    let archive_file = File::open(&archive_path)
+        .map_err(|e| format!("Failed to open archive file {:?}: {:?}", archive_path, e))?;
 
     let mut archive =
         ZipArchive::new(archive_file).map_err(|e| format!("Error with zip file: {}", e))?;
 
-    // Create testnet dir
-    fs::create_dir_all(testnet.dir())
-        .map_err(|e| format!("Failed to create testnet directory: {:?}", e))?;
-
-    // Create empty genesis.ssz if genesis is unknown
-    if !testnet.genesis_is_known {
-        File::create(testnet.dir().join("genesis.ssz"))
-            .map_err(|e| format!("Failed to create genesis.ssz: {}", e))?;
-    }
-
-    for i in 0..archive.len() {
-        let mut file = archive
-            .by_index(i)
-            .map_err(|e| format!("Error retrieving file {} inside zip: {}", i, e))?;
-
-        let path = testnet.dir().join(file.name());
-
+    if testnet.genesis_is_known {
+        let mut file = archive.by_name(GENESIS_FILE_NAME).map_err(|e| {
+            format!(
+                "Error retrieving file {} inside zip: {}",
+                GENESIS_FILE_NAME, e
+            )
+        })?;
+        let path = testnet.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
+        File::create(testnet.dir().join(GENESIS_FILE_NAME))
+            .map_err(|e| format!("Failed to create {}: {}", GENESIS_FILE_NAME, e))?;
     }
 
     Ok(())
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/boot_enr.yaml b/common/eth2_testnet_config/built_in_testnet_configs/altona/boot_enr.yaml
new file mode 100644
index 000000000..3e50ecd9d
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/altona/boot_enr.yaml
@@ -0,0 +1,10 @@
+- enr:-LK4QFtV7Pz4reD5a7cpfi1z6yPrZ2I9eMMU5mGQpFXLnLoKZW8TXvVubShzLLpsEj6aayvVO1vFx-MApijD3HLPhlECh2F0dG5ldHOIAAAAAAAAAACEZXRoMpD6etXjAAABIf__________gmlkgnY0gmlwhDMPYfCJc2VjcDI1NmsxoQIerw_qBc9apYfZqo2awiwS930_vvmGnW2psuHsTzrJ8YN0Y3CCIyiDdWRwgiMo
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+- enr:-LK4QLkbbq7xuRa_EnWd_kc0TkQk0pd0B0cZYR5LvBsncFQBDyPbGdy8d24TzRVeK7ZWwM5_2EcSJK223f8TYUOQYfwBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpD9yjmwAAABIf__________gmlkgnY0gmlwhAPsjtOJc2VjcDI1NmsxoQJNw_aZgWXl2SstD--WAjooGudjWLjEbbCIddJuEPxzWYN0Y3CCIyiDdWRwgiMo
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+- enr:-Ku4QMqmWPFkgM58F16wxB50cqWDaWaIsyANHL8wUNSB4Cy1TP9__uJQNRODvx_dvO6rY-BT3psrYTMAaxnMGXb6DuoBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpD1pf1CAAAAAP__________gmlkgnY0gmlwhBLf22SJc2VjcDI1NmsxoQNoed9JnQh7ltcAacHEGOjwocL1BhMQbYTgaPX0kFuXtIN1ZHCCE4g
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+- enr:-LK4QF3lT3Ch8Ljyx-KwoPrvoJHO-HDd3jOREMIZCWzi_HkHFVub5qt52MliDTLDgpXMS9tBzzLI4ObT_Z2m2Kus9vMBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpAAAAAAAAAAAAAAAAAAAAAAgmlkgnY0gmlwhBKNqHeJc2VjcDI1NmsxoQOTO9uI9UZjuTOpcWvnCfhfQTmcMaIzBFsjMpXYnppET4N0Y3CCIyiDdWRwgiMo
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/config.yaml b/common/eth2_testnet_config/built_in_testnet_configs/altona/config.yaml
new file mode 100644
index 000000000..bcda638e0
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/altona/config.yaml
@@ -0,0 +1,58 @@
+MAX_COMMITTEES_PER_SLOT: 64
+TARGET_COMMITTEE_SIZE: 128
+MAX_VALIDATORS_PER_COMMITTEE: 2048
+MIN_PER_EPOCH_CHURN_LIMIT: 4
+CHURN_LIMIT_QUOTIENT: 65536
+SHUFFLE_ROUND_COUNT: 90
+MIN_GENESIS_ACTIVE_VALIDATOR_COUNT: 640
+MIN_GENESIS_TIME: 1593433800
+HYSTERESIS_QUOTIENT: 4
+HYSTERESIS_DOWNWARD_MULTIPLIER: 1
+HYSTERESIS_UPWARD_MULTIPLIER: 5
+SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
+ETH1_FOLLOW_DISTANCE: 1024
+TARGET_AGGREGATORS_PER_COMMITTEE: 16
+RANDOM_SUBNETS_PER_VALIDATOR: 1
+EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
+SECONDS_PER_ETH1_BLOCK: 14
+DEPOSIT_CONTRACT_ADDRESS: 0x16e82D77882A663454Ef92806b7DeCa1D394810f
+MIN_DEPOSIT_AMOUNT: 1000000000
+MAX_EFFECTIVE_BALANCE: 32000000000
+EJECTION_BALANCE: 16000000000
+EFFECTIVE_BALANCE_INCREMENT: 1000000000
+GENESIS_FORK_VERSION: 0x00000121
+BLS_WITHDRAWAL_PREFIX: 0x00
+GENESIS_DELAY: 172800
+SECONDS_PER_SLOT: 12
+MIN_ATTESTATION_INCLUSION_DELAY: 1
+SLOTS_PER_EPOCH: 32
+MIN_SEED_LOOKAHEAD: 1
+MAX_SEED_LOOKAHEAD: 4
+EPOCHS_PER_ETH1_VOTING_PERIOD: 32
+SLOTS_PER_HISTORICAL_ROOT: 8192
+MIN_VALIDATOR_WITHDRAWABILITY_DELAY: 256
+SHARD_COMMITTEE_PERIOD: 256
+MIN_EPOCHS_TO_INACTIVITY_PENALTY: 4
+EPOCHS_PER_HISTORICAL_VECTOR: 65536
+EPOCHS_PER_SLASHINGS_VECTOR: 8192
+HISTORICAL_ROOTS_LIMIT: 16777216
+VALIDATOR_REGISTRY_LIMIT: 1099511627776
+BASE_REWARD_FACTOR: 64
+WHISTLEBLOWER_REWARD_QUOTIENT: 512
+PROPOSER_REWARD_QUOTIENT: 8
+INACTIVITY_PENALTY_QUOTIENT: 16777216
+MIN_SLASHING_PENALTY_QUOTIENT: 32
+MAX_PROPOSER_SLASHINGS: 16
+MAX_ATTESTER_SLASHINGS: 2
+MAX_ATTESTATIONS: 128
+MAX_DEPOSITS: 16
+MAX_VOLUNTARY_EXITS: 16
+DOMAIN_BEACON_PROPOSER: 0x00000000
+DOMAIN_BEACON_ATTESTER: 0x01000000
+DOMAIN_RANDAO: 0x02000000
+DOMAIN_DEPOSIT: 0x03000000
+DOMAIN_VOLUNTARY_EXIT: 0x04000000
+DOMAIN_SELECTION_PROOF: 0x05000000
+DOMAIN_AGGREGATE_AND_PROOF: 0x06000000
+DEPOSIT_CHAIN_ID: 5
+DEPOSIT_NETWORK_ID: 5
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/deploy_block.txt b/common/eth2_testnet_config/built_in_testnet_configs/altona/deploy_block.txt
new file mode 100644
index 000000000..5306ea664
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/altona/deploy_block.txt
@@ -0,0 +1 @@
+2917810
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/deposit_contract.txt b/common/eth2_testnet_config/built_in_testnet_configs/altona/deposit_contract.txt
new file mode 100644
index 000000000..3a81ea803
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/altona/deposit_contract.txt
@@ -0,0 +1 @@
+0x16e82D77882A663454Ef92806b7DeCa1D394810f
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/altona/genesis.ssz.zip b/common/eth2_testnet_config/built_in_testnet_configs/altona/genesis.ssz.zip
new file mode 100644
index 000000000..79fd978bb
Binary files /dev/null and b/common/eth2_testnet_config/built_in_testnet_configs/altona/genesis.ssz.zip differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/boot_enr.yaml b/common/eth2_testnet_config/built_in_testnet_configs/medalla/boot_enr.yaml
new file mode 100644
index 000000000..e4a81fa0a
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/medalla/boot_enr.yaml
@@ -0,0 +1,10 @@
+- enr:-LK4QKWk9yZo258PQouLshTOEEGWVHH7GhKwpYmB5tmKE4eHeSfman0PZvM2Rpp54RWgoOagAsOfKoXgZSbiCYzERWABh2F0dG5ldHOIAAAAAAAAAACEZXRoMpAAAAAAAAAAAAAAAAAAAAAAgmlkgnY0gmlwhDQlA5CJc2VjcDI1NmsxoQOYiWqrQtQksTEtS3qY6idxJE5wkm0t9wKqpzv2gCR21oN0Y3CCIyiDdWRwgiMo
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+
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/config.yaml b/common/eth2_testnet_config/built_in_testnet_configs/medalla/config.yaml
new file mode 100644
index 000000000..dbe384f5c
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/medalla/config.yaml
@@ -0,0 +1,58 @@
+MAX_COMMITTEES_PER_SLOT: 64
+TARGET_COMMITTEE_SIZE: 128
+MAX_VALIDATORS_PER_COMMITTEE: 2048
+MIN_PER_EPOCH_CHURN_LIMIT: 4
+CHURN_LIMIT_QUOTIENT: 65536
+SHUFFLE_ROUND_COUNT: 90
+MIN_GENESIS_ACTIVE_VALIDATOR_COUNT: 16384
+MIN_GENESIS_TIME: 1596546000
+HYSTERESIS_QUOTIENT: 4
+HYSTERESIS_DOWNWARD_MULTIPLIER: 1
+HYSTERESIS_UPWARD_MULTIPLIER: 5
+SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
+ETH1_FOLLOW_DISTANCE: 1024
+TARGET_AGGREGATORS_PER_COMMITTEE: 16
+RANDOM_SUBNETS_PER_VALIDATOR: 1
+EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
+SECONDS_PER_ETH1_BLOCK: 14
+DEPOSIT_CONTRACT_ADDRESS: 0x07b39F4fDE4A38bACe212b546dAc87C58DfE3fDC
+MIN_DEPOSIT_AMOUNT: 1000000000
+MAX_EFFECTIVE_BALANCE: 32000000000
+EJECTION_BALANCE: 16000000000
+EFFECTIVE_BALANCE_INCREMENT: 1000000000
+GENESIS_FORK_VERSION: 0x00000001
+BLS_WITHDRAWAL_PREFIX: 0x00
+GENESIS_DELAY: 172800
+SECONDS_PER_SLOT: 12
+MIN_ATTESTATION_INCLUSION_DELAY: 1
+SLOTS_PER_EPOCH: 32
+MIN_SEED_LOOKAHEAD: 1
+MAX_SEED_LOOKAHEAD: 4
+EPOCHS_PER_ETH1_VOTING_PERIOD: 32
+SLOTS_PER_HISTORICAL_ROOT: 8192
+MIN_VALIDATOR_WITHDRAWABILITY_DELAY: 256
+SHARD_COMMITTEE_PERIOD: 256
+MIN_EPOCHS_TO_INACTIVITY_PENALTY: 4
+EPOCHS_PER_HISTORICAL_VECTOR: 65536
+EPOCHS_PER_SLASHINGS_VECTOR: 8192
+HISTORICAL_ROOTS_LIMIT: 16777216
+VALIDATOR_REGISTRY_LIMIT: 1099511627776
+BASE_REWARD_FACTOR: 64
+WHISTLEBLOWER_REWARD_QUOTIENT: 512
+PROPOSER_REWARD_QUOTIENT: 8
+INACTIVITY_PENALTY_QUOTIENT: 16777216
+MIN_SLASHING_PENALTY_QUOTIENT: 32
+MAX_PROPOSER_SLASHINGS: 16
+MAX_ATTESTER_SLASHINGS: 2
+MAX_ATTESTATIONS: 128
+MAX_DEPOSITS: 16
+MAX_VOLUNTARY_EXITS: 16
+DOMAIN_BEACON_PROPOSER: 0x00000000
+DOMAIN_BEACON_ATTESTER: 0x01000000
+DOMAIN_RANDAO: 0x02000000
+DOMAIN_DEPOSIT: 0x03000000
+DOMAIN_VOLUNTARY_EXIT: 0x04000000
+DOMAIN_SELECTION_PROOF: 0x05000000
+DOMAIN_AGGREGATE_AND_PROOF: 0x06000000
+DEPOSIT_CHAIN_ID: 5
+DEPOSIT_NETWORK_ID: 5
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/deploy_block.txt b/common/eth2_testnet_config/built_in_testnet_configs/medalla/deploy_block.txt
new file mode 100644
index 000000000..a5ea0ed2e
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/medalla/deploy_block.txt
@@ -0,0 +1 @@
+3085928
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/deposit_contract.txt b/common/eth2_testnet_config/built_in_testnet_configs/medalla/deposit_contract.txt
new file mode 100644
index 000000000..5d53be4a8
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/medalla/deposit_contract.txt
@@ -0,0 +1 @@
+0x07b39F4fDE4A38bACe212b546dAc87C58DfE3fDC
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/medalla/genesis.ssz.zip b/common/eth2_testnet_config/built_in_testnet_configs/medalla/genesis.ssz.zip
new file mode 100644
index 000000000..761b72c0d
Binary files /dev/null and b/common/eth2_testnet_config/built_in_testnet_configs/medalla/genesis.ssz.zip differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/boot_enr.yaml b/common/eth2_testnet_config/built_in_testnet_configs/spadina/boot_enr.yaml
new file mode 100644
index 000000000..e5da1c73c
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/spadina/boot_enr.yaml
@@ -0,0 +1,8 @@
+# Lighthouse
+- enr:-KG4QEPVpcw8HLNsDuqNPIx4sXLCUsuDOHVtPcNmgSewWcDgSkd6s-vGCXlac86BTYIU8sYqhvD-ZeTW1uG5OtEBm-QDhGV0aDKQCfsKEgAAAAL__________4JpZIJ2NIJpcIQ0ECjWiXNlY3AyNTZrMaEDCavdC37lb2fgBgKrvrLRZ-ZvL6JFNeUHHc5TXZ_BYqmDdGNwgiMog3VkcIIjKA
+# teku
+- enr:-KG4QA-EcFfXQsL2dcneG8vp8HTWLrpwHQ5HhfyIytfpeKOISzROy2kYSsf_v-BZKnIx5XHDjqJ-ttz0hoz6qJA7tasEhGV0aDKQxKgkDQAAAAL__________4JpZIJ2NIJpcIQDFt-UiXNlY3AyNTZrMaECkR4C5DVO_9rB48eHTY4kdyOHsguTEDlvb7Ce0_mvghSDdGNwgiMog3VkcIIjKA
+# prysm 
+- enr:-Ku4QGQJf2bcDAwVGvbvtq3AB4KKwAvStTenY-i_QnW2ABNRRBncIU_5qR_e_um-9t3s9g-Y5ZfFATj1nhtzq6lvgc4Bh2F0dG5ldHOIAAAAAAAAAACEZXRoMpDEqCQNAAAAAv__________gmlkgnY0gmlwhBLf22SJc2VjcDI1NmsxoQNoed9JnQh7ltcAacHEGOjwocL1BhMQbYTgaPX0kFuXtIN1ZHCCE4g
+# proto
+- enr:-Ku4QFW1SLbtzJ_ghQQC8-8xezvZ1Mx95J-zer9IPmDE2BKeD_SM7j4vH6xmroUFVuyK-54n2Ey2ueB-Lf-fkbcLwAQBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpDEqCQNAAAAAv__________gmlkgnY0gmlwhGQZkSyJc2VjcDI1NmsxoQJMcbZhTCEKYSH5-qPQPgYfSHHUMLGBAKU-f-96yYKFMIN1ZHCCIyg
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/config.yaml b/common/eth2_testnet_config/built_in_testnet_configs/spadina/config.yaml
new file mode 100644
index 000000000..59b810531
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/spadina/config.yaml
@@ -0,0 +1,59 @@
+MAX_COMMITTEES_PER_SLOT: 64
+TARGET_COMMITTEE_SIZE: 128
+MAX_VALIDATORS_PER_COMMITTEE: 2048
+MIN_PER_EPOCH_CHURN_LIMIT: 4
+CHURN_LIMIT_QUOTIENT: 65536
+SHUFFLE_ROUND_COUNT: 90
+MIN_GENESIS_ACTIVE_VALIDATOR_COUNT: 1024
+MIN_GENESIS_TIME: 1601380800
+HYSTERESIS_QUOTIENT: 4
+HYSTERESIS_DOWNWARD_MULTIPLIER: 1
+HYSTERESIS_UPWARD_MULTIPLIER: 5
+PROPORTIONAL_SLASHING_MULTIPLIER: 3
+SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
+ETH1_FOLLOW_DISTANCE: 1024
+TARGET_AGGREGATORS_PER_COMMITTEE: 16
+RANDOM_SUBNETS_PER_VALIDATOR: 1
+EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
+SECONDS_PER_ETH1_BLOCK: 14
+DEPOSIT_CHAIN_ID: 5
+DEPOSIT_NETWORK_ID: 5
+DEPOSIT_CONTRACT_ADDRESS: 0x48B597F4b53C21B48AD95c7256B49D1779Bd5890
+MIN_DEPOSIT_AMOUNT: 1000000000
+MAX_EFFECTIVE_BALANCE: 32000000000
+EJECTION_BALANCE: 16000000000
+EFFECTIVE_BALANCE_INCREMENT: 1000000000
+GENESIS_FORK_VERSION: 0x00000002
+BLS_WITHDRAWAL_PREFIX: 0x00
+GENESIS_DELAY: 172800
+SECONDS_PER_SLOT: 12
+MIN_ATTESTATION_INCLUSION_DELAY: 1
+SLOTS_PER_EPOCH: 32
+MIN_SEED_LOOKAHEAD: 1
+MAX_SEED_LOOKAHEAD: 4
+EPOCHS_PER_ETH1_VOTING_PERIOD: 32
+SLOTS_PER_HISTORICAL_ROOT: 8192
+MIN_VALIDATOR_WITHDRAWABILITY_DELAY: 256
+SHARD_COMMITTEE_PERIOD: 256
+MIN_EPOCHS_TO_INACTIVITY_PENALTY: 4
+EPOCHS_PER_HISTORICAL_VECTOR: 65536
+EPOCHS_PER_SLASHINGS_VECTOR: 8192
+HISTORICAL_ROOTS_LIMIT: 16777216
+VALIDATOR_REGISTRY_LIMIT: 1099511627776
+BASE_REWARD_FACTOR: 64
+WHISTLEBLOWER_REWARD_QUOTIENT: 512
+PROPOSER_REWARD_QUOTIENT: 8
+INACTIVITY_PENALTY_QUOTIENT: 16777216
+MIN_SLASHING_PENALTY_QUOTIENT: 32
+MAX_PROPOSER_SLASHINGS: 16
+MAX_ATTESTER_SLASHINGS: 2
+MAX_ATTESTATIONS: 128
+MAX_DEPOSITS: 16
+MAX_VOLUNTARY_EXITS: 16
+DOMAIN_BEACON_PROPOSER: 0x00000000
+DOMAIN_BEACON_ATTESTER: 0x01000000
+DOMAIN_RANDAO: 0x02000000
+DOMAIN_DEPOSIT: 0x03000000
+DOMAIN_VOLUNTARY_EXIT: 0x04000000
+DOMAIN_SELECTION_PROOF: 0x05000000
+DOMAIN_AGGREGATE_AND_PROOF: 0x06000000
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/deploy_block.txt b/common/eth2_testnet_config/built_in_testnet_configs/spadina/deploy_block.txt
new file mode 100644
index 000000000..afa03d34e
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/spadina/deploy_block.txt
@@ -0,0 +1 @@
+3384340
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/deposit_contract.txt b/common/eth2_testnet_config/built_in_testnet_configs/spadina/deposit_contract.txt
new file mode 100644
index 000000000..155f62319
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/spadina/deposit_contract.txt
@@ -0,0 +1 @@
+0x48B597F4b53C21B48AD95c7256B49D1779Bd5890
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/spadina/genesis.ssz.zip b/common/eth2_testnet_config/built_in_testnet_configs/spadina/genesis.ssz.zip
new file mode 100644
index 000000000..3b97893c5
Binary files /dev/null and b/common/eth2_testnet_config/built_in_testnet_configs/spadina/genesis.ssz.zip differ
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/zinken/boot_enr.yaml b/common/eth2_testnet_config/built_in_testnet_configs/zinken/boot_enr.yaml
new file mode 100644
index 000000000..f29496ed6
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/zinken/boot_enr.yaml
@@ -0,0 +1,4 @@
+- enr:-KG4QHPtVnKHEOkEJT1f5C6Hs-C_c4SlipTfkPrDIikLTzhqA_3m6bTq-CirsljlVP4IJybXelHE7J3l9DojR14_ZHUGhGV0aDKQ2jUIggAAAAP__________4JpZIJ2NIJpcIQSv2qciXNlY3AyNTZrMaECi_CNPDkKPilhimY7aEY-mBtSzI8AKMDvvv_I2Un74_qDdGNwgiMog3VkcIIjKA
+- enr:-Ku4QH63huZ12miIY0kLI9dunG5fwKpnn-zR3XyA_kH6rQpRD1VoyLyzIcFysCJ09JDprdX-EzXp-Nc8swYqBznkXggBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpDaNQiCAAAAA___________gmlkgnY0gmlwhBLf22SJc2VjcDI1NmsxoQILqxBY-_SF8o_5FjFD3yM92s50zT_ciFi8hStde5AEjIN1ZHCCH0A
+- enr:-Ku4QMGGAuQO8NPhYCz29wsahrFR-betfxKx6ltyzLUM70yJWoaRjJZ-n1Oiof2PiKnzjVG1n6RoyO4ZNJkQtqEkqNkBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpDaNQiCAAAAA___________gmlkgnY0gmlwhDZUyU6Jc2VjcDI1NmsxoQNMOowBnXeUYjK71_Zz78j3y7EYKSXH9ZGhYB4wB6V8lIN1ZHCCIyg
+- enr:-KG4QDCt7b_zpzEoKEATUYgvdfBy28DCtGs54E4U_IIKd5e1Pj71nUAJKqdNjjqH5L8wNVsGNI67dzX5_ATfVMHQ7ygChGV0aDKQufleewAAAAP__________4JpZIJ2NIJpcIQ0ECjWiXNlY3AyNTZrMaEC64bJmIc-R6ynv5PqUqMBjblHILK46WWi4bbXO9DAGbeDdGNwgiMog3VkcIIjKA
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/zinken/config.yaml b/common/eth2_testnet_config/built_in_testnet_configs/zinken/config.yaml
new file mode 100644
index 000000000..d5231127a
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/zinken/config.yaml
@@ -0,0 +1,60 @@
+CONFIG_NAME: "zinken"
+MAX_COMMITTEES_PER_SLOT: 64
+TARGET_COMMITTEE_SIZE: 128
+MAX_VALIDATORS_PER_COMMITTEE: 2048
+MIN_PER_EPOCH_CHURN_LIMIT: 4
+CHURN_LIMIT_QUOTIENT: 65536
+SHUFFLE_ROUND_COUNT: 90
+MIN_GENESIS_ACTIVE_VALIDATOR_COUNT: 1024
+MIN_GENESIS_TIME: 1602504000
+HYSTERESIS_QUOTIENT: 4
+HYSTERESIS_DOWNWARD_MULTIPLIER: 1
+HYSTERESIS_UPWARD_MULTIPLIER: 5
+PROPORTIONAL_SLASHING_MULTIPLIER: 3
+SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
+ETH1_FOLLOW_DISTANCE: 1024
+TARGET_AGGREGATORS_PER_COMMITTEE: 16
+RANDOM_SUBNETS_PER_VALIDATOR: 1
+EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
+SECONDS_PER_ETH1_BLOCK: 14
+DEPOSIT_CHAIN_ID: 5
+DEPOSIT_NETWORK_ID: 5
+DEPOSIT_CONTRACT_ADDRESS: 0x99F0Ec06548b086E46Cb0019C78D0b9b9F36cD53
+MIN_DEPOSIT_AMOUNT: 1000000000
+MAX_EFFECTIVE_BALANCE: 32000000000
+EJECTION_BALANCE: 16000000000
+EFFECTIVE_BALANCE_INCREMENT: 1000000000
+GENESIS_FORK_VERSION: 0x00000003
+BLS_WITHDRAWAL_PREFIX: 0x00
+GENESIS_DELAY: 345600
+SECONDS_PER_SLOT: 12
+MIN_ATTESTATION_INCLUSION_DELAY: 1
+SLOTS_PER_EPOCH: 32
+MIN_SEED_LOOKAHEAD: 1
+MAX_SEED_LOOKAHEAD: 4
+EPOCHS_PER_ETH1_VOTING_PERIOD: 32
+SLOTS_PER_HISTORICAL_ROOT: 8192
+MIN_VALIDATOR_WITHDRAWABILITY_DELAY: 256
+SHARD_COMMITTEE_PERIOD: 256
+MIN_EPOCHS_TO_INACTIVITY_PENALTY: 4
+EPOCHS_PER_HISTORICAL_VECTOR: 65536
+EPOCHS_PER_SLASHINGS_VECTOR: 8192
+HISTORICAL_ROOTS_LIMIT: 16777216
+VALIDATOR_REGISTRY_LIMIT: 1099511627776
+BASE_REWARD_FACTOR: 64
+WHISTLEBLOWER_REWARD_QUOTIENT: 512
+PROPOSER_REWARD_QUOTIENT: 8
+INACTIVITY_PENALTY_QUOTIENT: 16777216
+MIN_SLASHING_PENALTY_QUOTIENT: 32
+MAX_PROPOSER_SLASHINGS: 16
+MAX_ATTESTER_SLASHINGS: 2
+MAX_ATTESTATIONS: 128
+MAX_DEPOSITS: 16
+MAX_VOLUNTARY_EXITS: 16
+DOMAIN_BEACON_PROPOSER: 0x00000000
+DOMAIN_BEACON_ATTESTER: 0x01000000
+DOMAIN_RANDAO: 0x02000000
+DOMAIN_DEPOSIT: 0x03000000
+DOMAIN_VOLUNTARY_EXIT: 0x04000000
+DOMAIN_SELECTION_PROOF: 0x05000000
+DOMAIN_AGGREGATE_AND_PROOF: 0x06000000
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/zinken/deploy_block.txt b/common/eth2_testnet_config/built_in_testnet_configs/zinken/deploy_block.txt
new file mode 100644
index 000000000..6b0325b6f
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/zinken/deploy_block.txt
@@ -0,0 +1 @@
+3488417
diff --git a/common/eth2_testnet_config/built_in_testnet_configs/zinken/deposit_contract.txt b/common/eth2_testnet_config/built_in_testnet_configs/zinken/deposit_contract.txt
new file mode 100644
index 000000000..67b5d86b2
--- /dev/null
+++ b/common/eth2_testnet_config/built_in_testnet_configs/zinken/deposit_contract.txt
@@ -0,0 +1 @@
+0x99F0Ec06548b086E46Cb0019C78D0b9b9F36cD53
diff --git a/common/eth2_testnet_config/testnet_zinken.zip b/common/eth2_testnet_config/built_in_testnet_configs/zinken/genesis.ssz.zip
similarity index 99%
rename from common/eth2_testnet_config/testnet_zinken.zip
rename to common/eth2_testnet_config/built_in_testnet_configs/zinken/genesis.ssz.zip
index 1457638d1..c0c8c69e5 100644
Binary files a/common/eth2_testnet_config/testnet_zinken.zip and b/common/eth2_testnet_config/built_in_testnet_configs/zinken/genesis.ssz.zip differ
diff --git a/common/eth2_testnet_config/src/lib.rs b/common/eth2_testnet_config/src/lib.rs
index 37d532145..572eb168e 100644
--- a/common/eth2_testnet_config/src/lib.rs
+++ b/common/eth2_testnet_config/src/lib.rs
@@ -8,7 +8,8 @@
 //! https://github.com/sigp/lighthouse/pull/605
 //!
 use eth2_config::{
-    include_altona_file, include_medalla_file, include_spadina_file, include_zinken_file, unique_id,
+    include_altona_file, include_medalla_file, include_spadina_file, include_zinken_file,
+    testnets_dir,
 };
 
 use enr::{CombinedKey, Enr};
@@ -26,7 +27,6 @@ pub const YAML_CONFIG_FILE: &str = "config.yaml";
 
 #[derive(Copy, Clone, Debug, PartialEq)]
 pub struct HardcodedNet {
-    pub unique_id: &'static str,
     pub name: &'static str,
     pub genesis_is_known: bool,
     pub yaml_config: &'static [u8],
@@ -41,7 +41,6 @@ macro_rules! define_net {
         use eth2_config::$mod::ETH2_NET_DIR;
 
         HardcodedNet {
-            unique_id: ETH2_NET_DIR.unique_id,
             name: ETH2_NET_DIR.name,
             genesis_is_known: ETH2_NET_DIR.genesis_is_known,
             yaml_config: $include_file!("../", "config.yaml"),
@@ -259,8 +258,14 @@ mod tests {
     #[test]
     fn hard_coded_nets_work() {
         for net in HARDCODED_NETS {
-            let config = Eth2TestnetConfig::<E>::from_hardcoded_net(net).unwrap();
-            assert_eq!(config.genesis_state.is_some(), net.genesis_is_known);
+            let config =
+                Eth2TestnetConfig::<E>::from_hardcoded_net(net).expect(&format!("{:?}", net.name));
+            assert_eq!(
+                config.genesis_state.is_some(),
+                net.genesis_is_known,
+                "{:?}",
+                net.name
+            );
         }
     }
 
diff --git a/common/eth2_testnet_config/testnet_altona.zip b/common/eth2_testnet_config/testnet_altona.zip
deleted file mode 100644
index b2c264803..000000000
Binary files a/common/eth2_testnet_config/testnet_altona.zip and /dev/null differ
diff --git a/common/eth2_testnet_config/testnet_medalla.zip b/common/eth2_testnet_config/testnet_medalla.zip
deleted file mode 100644
index 13f6d069d..000000000
Binary files a/common/eth2_testnet_config/testnet_medalla.zip and /dev/null differ
diff --git a/common/eth2_testnet_config/testnet_spadina.zip b/common/eth2_testnet_config/testnet_spadina.zip
deleted file mode 100644
index a1cf5e206..000000000
Binary files a/common/eth2_testnet_config/testnet_spadina.zip and /dev/null differ
diff --git a/consensus/types/src/chain_spec.rs b/consensus/types/src/chain_spec.rs
index 7327895ee..4cf56afe0 100644
--- a/consensus/types/src/chain_spec.rs
+++ b/consensus/types/src/chain_spec.rs
@@ -108,6 +108,8 @@ pub struct ChainSpec {
      */
     pub eth1_follow_distance: u64,
     pub seconds_per_eth1_block: u64,
+    pub deposit_chain_id: u64,
+    pub deposit_network_id: u64,
     pub deposit_contract_address: Address,
 
     /*
@@ -320,6 +322,8 @@ impl ChainSpec {
              */
             eth1_follow_distance: 1_024,
             seconds_per_eth1_block: 14,
+            deposit_chain_id: 1,
+            deposit_network_id: 1,
             deposit_contract_address: "1234567890123456789012345678901234567890"
                 .parse()
                 .expect("chain spec deposit contract address"),
@@ -357,6 +361,8 @@ impl ChainSpec {
             milliseconds_per_slot: 6_000,
             safe_slots_to_update_justified: 2,
             network_id: 2, // lighthouse testnet network id
+            deposit_chain_id: 5,
+            deposit_network_id: 5,
             boot_nodes,
             ..ChainSpec::mainnet()
         }
@@ -440,7 +446,7 @@ mod tests {
 ///
 /// Spec v0.12.3
 #[derive(Serialize, Deserialize, Debug, PartialEq, Clone)]
-#[serde(rename_all = "UPPERCASE")]
+#[serde(rename_all = "UPPERCASE", deny_unknown_fields)]
 pub struct YamlConfig {
     #[serde(default)]
     config_name: String,
@@ -562,11 +568,11 @@ pub struct YamlConfig {
     epochs_per_random_subnet_subscription: u64,
     #[serde(with = "serde_utils::quoted_u64")]
     seconds_per_eth1_block: u64,
-    deposit_contract_address: Address,
-    /* TODO: incorporate these into ChainSpec and turn on `serde(deny_unknown_fields)`
+    #[serde(with = "serde_utils::quoted_u64")]
     deposit_chain_id: u64,
+    #[serde(with = "serde_utils::quoted_u64")]
     deposit_network_id: u64,
-    */
+    deposit_contract_address: Address,
 }
 
 // Compatibility shim for proportional slashing multpilier on Altona and Medalla.
@@ -648,6 +654,8 @@ impl YamlConfig {
             random_subnets_per_validator: spec.random_subnets_per_validator,
             epochs_per_random_subnet_subscription: spec.epochs_per_random_subnet_subscription,
             seconds_per_eth1_block: spec.seconds_per_eth1_block,
+            deposit_chain_id: spec.deposit_chain_id,
+            deposit_network_id: spec.deposit_network_id,
             deposit_contract_address: spec.deposit_contract_address,
         }
     }
@@ -768,6 +776,8 @@ impl YamlConfig {
             genesis_slot: chain_spec.genesis_slot,
             far_future_epoch: chain_spec.far_future_epoch,
             base_rewards_per_epoch: chain_spec.base_rewards_per_epoch,
+            deposit_chain_id: chain_spec.deposit_chain_id,
+            deposit_network_id: chain_spec.deposit_network_id,
             deposit_contract_tree_depth: chain_spec.deposit_contract_tree_depth,
         })
     }