# Supported Networks

Use the flag `--chain=<tag>` to sync one of the supported network.

<table><thead><tr><th>Chain name</th><th>Tag</th><th data-type="number">ChainId</th></tr></thead><tbody><tr><td>Ethereum</td><td><code>mainnet</code></td><td>1</td></tr><tr><td>Holesky Testnet</td><td><code>holesky</code></td><td>17000</td></tr><tr><td>Sepolia Testnet</td><td><code>sepolia</code></td><td>11155111</td></tr><tr><td>Polygon</td><td><code>bor-mainnet</code></td><td>137</td></tr><tr><td>Polygon Amoy Testnet</td><td><code>amoy</code></td><td>80002</td></tr><tr><td>Gnosis Chain</td><td><code>gnosis</code></td><td>100</td></tr><tr><td>Gnosis Chain Chiado Testnet</td><td><code>chiado</code></td><td>10200</td></tr></tbody></table>

## External implementations

The following implementations are not officially supported by Erigon, but are maintained by their respective teams:

* **Ethereum Classic** <https://github.com/ETCCooperative/erigon>
* **Binance Smart Chain** <https://github.com/node-real/bsc-erigon/>
* **Optimism** <https://github.com/testinprod-io/op-erigon>