Some Schools or Institutions can have more than one internet link, from different providers. While a common option is to load balance across the different links, Sonar can also direct traffic for different groups out different internet links. This is useful for when you want to separate Staff and Students from using the same internet link, or you want to have a dedicated server using a particular link, and not have other traffic interfere. So how do we split users between your two links?

Each Group on Sonar has an upstream cache IP and port. Using this, we can point certain groups out a certain internet links that we must configure in the Squid Cache first. You can edit the Squid Config in the Sonar GUI, by navigating to Network -> CacheBy default, Squid runs on port 3128. In order for us to add a new link, we must enable another port for Squid to run on. It can essentially be any other port, but for the purpose of keeping things neat and in order, for this example, we will use 3129. At the bottim of the Squid Config, we will enter the following lines:

  • htto_port

This will enable Squid to run on 3129. Next, we must create an ACL (Access Control List) so Squid can reference port 3129.

  • acl SecondaryLink myport 3129

Where "SecondaryLink" is the name you give the ACL to reference the port. The name can be anything you wish to name it. Following this, we now direct the traffic out the desired internet link referencing the ACL we just created.

  • tcp_outgoing_address SecondaryLink.

Where is the IP address of your Secondary Internet Link on Sonar. With these 3 configurations in place, we now have to change the Upstream Cache Port of the Groups you want to direct out the Secondary Internet Link. Open up Groups in the GUI, navigate to the desired group and under Rules -> HTTP, you'll notice an Upstream Cache IP and Port field below. Change the port from 3128 to 3129 and click Apply.

To test whether the configuration is working, ensure that you are connected to the proxy and go to The public IP that comes back should tell you which Link you're going out of.