Squid Transparent Proxy in Linux + pfSense Firewall (Help)

Networking Networking Software
1

Hey there,

Here's my setup:

Proxmox Server containing:

  1. pfSense KVM (Firewall + NAT) working fine as is no issue on that.
  2. Debian LXC (squid for caching)

I don't want to use squid within pfSense because pfSense has a limitaion where squid can't work with gateway groups (which are fundamental for my setup).

I created a network interface in pfSense called SQUID that has an IP address of 192.168.5.1/30 which runs on its own vlan VLAN3. The squid LXC in proxmox has a network adapter on VLAN3 with IP address 192.168.5.2/30 and gateway 192.168.5.1

I created a firewall rule on SQUID interface which allows SQUID_net to any through my specified gateway group.

I created a firewall rule on LAN interface which allows LAN_net to SQUID_net.

Everything is cool so far. squid has internet access. LAN has access to squid

Now in my squid LXC vm:

sudo apt update && sudo apt install squid3

I edited /etc/squid3/squid.conf

Changed #http_access deny all to http_access allow all

Changed http_port 3128 to http_port 3128 transparent

sudo service squid3 restart

In pfSense:

In NAT portforwarding I added this:

Interface: LAN

Source: LAN_net
Source port: any

Destination: any
Destiation port: 80

Redirect IP: 192.168.5.2 (squid)
Redirect port: 3128

Right now I expect that http requests from my LAN clients (192.168.3.0/24) should be redirected to squid (192.168.5.2) on squid's port (3128).

However, what I get when I try to access http websites on my LAN is an error message in chrome "ERR_EMPTY_RESPONSE".

It is confirmed that pfSense is doing what it's supposed to do in forwarding the ports. The only issue as I see it is a miss-configuration on squid's side.

Any help is highly appreciated.

2

If you want it to work transparently then it needs to be bridged between the lan interface and the lan network. To have it work in a routed configuration like that requires you to configure it manually on each device.

Pretty sure, there may be some dhcp setting you can use to get it working but I don't know.

Squid on pfsense used to work with different gateways just fine, you used to be able to configure firewall rules like normal and squid would honor any gateway settings. But then they changed the order of operation so now squid just uses the default gateway and theres nothing you can do about that apparently.