[squid-users] squid5 Happy Eyeballs - Is it possible to enable IPV4 only or IPV6 only ?

[Alex Rousskov]

On 5/3/22 09:04, Alex Rousskov wrote:
> On 5/3/22 02:35, Francesco Chemolli wrote:
>> Could tcp_outgoing_address do the deed, forcing a certain source ip or 
>> ipv4-only interface for some or all requests?
> 
> No, not without Squid modifications[1]: Today, tcp_outgoing_address is 
> consulted _after_ the address family is already decided for the current 
> connection attempt (by the peer selection algorithms selecting a 
> specific destination address). We can change that, of course, but 
> probably not without some backward compatibility headaches.
> 
> [1] Unless, perhaps, one abuses tcp_outgoing_address to select an 
> immediately failing source IP address (e.g., the one Squid cannot bind 
> to?) as a way to force another attempt (hopefully using another address 
> family). I do not know whether this hack would work, and suspect it 
> would depend on which socket operation fails when using the special 
> "force failure" source IP address.


More ideas along those lines can be found on the following thread:
http://lists.squid-cache.org/pipermail/squid-users/2019-October/021186.html

Alex.



>> On Mon, 2 May 2022 at 16:39, Alex Rousskov wrote:
>>
>>     On 5/1/22 23:49, Ahmad Alzaeem wrote:
>>
>>      > sometime the IPV4
>>      > instance receive DNS resolution of the destination as IPV6 and the
>>      > connection fails !!
>>      >
>>      > sometimes the IPV4 instance receive the DNS resolution of the
>>      > destination as IPV6 and the connection fail .
>>      >
>>      > Is there any option we can do based on the environment above ?
>>
>>
>>     Without Squid code modifications, your options are:
>>
>>     * Use a custom DNS resolver (configuration) that never sends IPv4
>>     address records to an IPv6-only Squid. Use a custom DNS resolver
>>     (configuration) that never sends IPv6 address records to an IPv4-only
>>     Squid. Configure each Squid to use the right resolver (see
>>     dns_nameservers).
>>
>>     * Disable IPv6 support in IPv4-only Squid at ./configure time. This
>>     does
>>     not help with the IPv6-only Squid and has other negative side
>>     effects. I
>>     do not recommend this option.
>>
>>
>>       > Like maybe we disable eyeballs or preserving it while add an 
>> option
>>       > like DNS A records or DNS AAAA records .
>>
>>     It would be possible to enhance Squid by adding a configuration 
>> option
>>     that disables (certain) A or AAAA queries, but proper 
>> modifications are
>>     not trivial and nobody has done them yet:
>>     
>> https://wiki.squid-cache.org/SquidFaq/AboutSquid#How_to_add_a_new_Squid_feature.2C_enhance.2C_of_fix_something.3F 
>>
>>     
>> <https://wiki.squid-cache.org/SquidFaq/AboutSquid#How_to_add_a_new_Squid_feature.2C_enhance.2C_of_fix_something.3F> 
>>
>>
>>
>>     Cheers,
>>
>>     Alex.
>>
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>> -- 
>> @mobile
>