[sdnog] configure outgoing configuration based on incoming ports

[Patrick Okui]

Hi Samir, all,

On 29 Jun 2016, at 10:59 EAT, Samir S. Omer wrote:

> Hi all
>
> I'm configuring a Linux CentOS machine with multiple virtual IPs to 
> run a squid service listening on different ports.
> how can I bind requests coming for each port to go through specific IP 
> ?
>
> for example requests coming to port 8081 to go out with the IP 
> 192.168.1.1 and requests coming through port 8082 goes out with IP 
> 192.168.1.2
>
> incoming -> Squid -> Outgoing
> *:8081   -> Squid -> 192.168.1.1:80
> *:8082   -> Squid -> 192.168.1.2:80


You want the configuration directive tcp_outgoing_address (it won’t 
fix the port number but it’ll fix the outgoing ip address).

Documentation for this is at 
<http://www.squid-cache.org/Doc/config/tcp_outgoing_address/>


In short you also need an ACL to match the incoming packets. So 
something along the following lines


acl net1 localport 8081
acl net2 localport 8082

tcp_outgoing_address 192.168.1.1 net1
tcp_outgoing_address 192.168.1.2 net2

Please read the configuration for tcp_outgoing_address, it lists some 
configuration options it is incompatible with e.g TPROXY.

The ACL documentation is at <http://www.squid-cache.org/Doc/config/acl/>

If you have ipv6 on your network you also need a tcp_outgoing_address 
entry either for each entry based on your port numbers or a general one 
that matches all ipv6 addresses.

I’m curious though why you need to do this.

--
patrick