Squid - Listen on multiple ports and forward to different proxy

Question

I would like to setup a proxy that listens for multiple ports and each port forwards the requests to different proxies, for example:

LISTEN          FORWARD TO 
1.2.3.4:3128 -> 5.6.7.8:3128
1.2.3.4:3129 -> 5.6.7.9:3128
1.2.3.4:3130 -> 5.6.7.10:3128

Is this possible to implement with squid?

I have configured this so far:

cache_peer 5.6.7.8 parent 3128 0000 default no-query no-digest
cache_peer 5.6.7.9 parent 3128 0000 default no-query no-digest
cache_peer 5.6.7.10 parent 3128 0000 default no-query no-digest

http_port 3128
http_port 3129
http_port 3130

I don't know how to handle the redirection

Answer 1

You are missing cache_peer_access and the acl.

Try this config:

acl port_1 localport 3128
acl port_2 localport 3129
acl port_3 localport 3130 # I woudn't use this one, This is reserved for ICP

http_port 3128
http_port 3129
http_port 3130

cache_peer 5.6.7.8 parent 3128 0 name=host_1
cache_peer 5.6.7.9 parent 3128 0 name=host_2
cache_peer 5.6.7.10 parent 3128 0 name=host_3

cache_peer_access host_1 allow port_1
cache_peer_access host_2 allow port_2
cache_peer_access host_3 allow port_3

never_direct allow all # Tells your squid to never use its own internet connection to process the requests. If your parent proxy won't work it will return an Error.   

GL!