There is step while configuring fabric network to update anchor peer. There is one anchor peer per organization, but not able to understand why do we need anchor peer.
A peer node on a channel that all other peers can discover and communicate with. Each Member on a channel has an anchor peer (or multiple anchor peers to prevent single point of failure), allowing for peers belonging to different Members to discover all existing peers on a channel.
You can read about this in glossary on hyperledjer fabric web site:
https://hyperledger-fabric.readthedocs.io/en/release-1.1/glossary.html#anchor-peer