[squid-users] Prefer or force ipv6 usage on dual stack interface

[Amos Jeffries]

On 17/07/24 01:31, Rasmus Horndrup wrote:
> Hi,
> On a dual stack network interface I’m interested in using squid as a ipv6 only forward proxy.
> My general understanding was that squid will prefer to use ipv6 whenever available, but I’m having issues with squid seemingly preferring ipv4 in some cases.
> 
> I have two examples, where it proceeds using IPv6 for the first and IPv4 for the second.
> 
>  From the looks of it, they both successfully receive A and AAAA records, but how can I basically force squid to use IPv6?
> 

Squid obeys the IPv6 specifications which still require IPv4 transition 
capabilities. Including whether you are on an IPv4-only or IPv6-only or 
Dual-Stack network.

The best way to make Squid IPv6-only is to make the machine it is 
running on IPv6-only.

Alternatively, to setup a firewall rule matching the proxy by PID/UID to 
reject TCPv4 connections with an ICMP "(3) Destination Unreachable" packet.


Cheers
Amos