Is it Possible to Configure Upstream Proxy?

Q: We have deployed Web Safety within our LAN but according to the corporate policies it needs to utilize upstream proxy and thus cannot go direct to the Internet. How to configure it in Admin UI?

A: Currently there is no specific part in Admin UI that can be used to easily configure upstream proxy but this can be done by using some advanced ACLs manually.

Open Admin UI / Squid / Settings / Default ACLs page. Type the following into the Advanced text area.

cache_peer 10.1.2.3 parent 3128 0 no-query default
never_direct allow all

Be sure to change the 10.1.2.3 to the actual IP address of your upstream proxy and check that 3128 is indeed the port your upstream proxy listens on. After clicking Save and Restart in Admin UI, all connections should now go through the upstream proxy and not directly.

You can read more info at https://wiki.squid-cache.org/Features/CacheHierarchy