Joining a cache hierarchy

In the previous chapters, we learned about the cache_peer directive in the Squid configuration file and how to use cache_peer to add other proxy servers in our configuration file, so that our proxy server can forward requests to neighbors. However, we only had a brief overview of the options used along with cache_peer. In this chapter, we'll explore cache_peer and its various options in detail.

The following is the format to add a proxy server in a configuration file using cache_peer:

cache_peer HOSTNAME TYPE HTTP_PORT ICP_OR_HTCP_PORT [OPTIONS]

The parameter HOSTNAME is the IP address or domain name of the proxy server we are trying to add to the configuration file. The TYPE parameter takes one of the values parent, sibling, or multicast, and specifies the type of the proxy server, which further determines the type of communication between the two servers.

Note

Please note that DNS resolution must be working if you want to use domain name as a value for the HOSTNAME...