[squid-users] Squid v4.1: commBind Cannot bind [::1] on SNMP with no ipv6

[Amos Jeffries]

On 15/07/18 11:40, David Touzeau wrote:
> Hi
> 
>  
> 
> Hi,
> 
>  
> 
> Ipv6 is not enabled on this Debian 9 system.
> 

Nod. That would be why is cannot open IPv6 sockets.

Squid is designed to comply with RFC 6540 (aka BCP 177), and to assume
the machine it is running on also complies:
 "IPv6 Support Required for All IP-Capable Nodes"

Anyhow ...

> 
> Squid try to open a socket on ipv6 loopback…
> 
>  
> 
> 2018/07/15 01:32:45 kid2| Sending SNMP messages from 0.0.0.0:3401
> 

Above says SNMP is working fine.

Then _something else_ has issues ...

> 2018/07/15 01:32:45 kid2| commBind Cannot bind socket FD 155 to [::1]:
> (99) Cannot assign requested address
> 
> 2018/07/15 01:32:45 kid2| commBind Cannot bind socket FD 156 to [::1]:
> (99) Cannot assign requested address
> 
> 2018/07/15 01:32:45 kid2| ERROR: Failed to create helper child read FD:
> UDP[::1]
> 

One of the helpers you are using needs IPv6 to send UDP packets to/from
Squid.

I would look at external_acl_type helpers. That is usually the one which
surprises IPv4-only people.

When your Squid is built to assume enabled IPv6 and your machine is
setup to disable it, you need to add the "ipv4" option to your
external_acl_type helper config lines.

PS. from the config given it looks like you don't need that snmpConsole
ACL. The built-in localhost ACL covers the same case(s) and will also
continue working if/when you decide to enable IPv6 within your network.

Amos