Re: After enabling IPv6 curl github.com fails, succeeds with IPv4

> From: Mayuresh <[email protected]>
> Date: Tue, 21 Jul 2026 22:34:18 +0530
> 
> On Tue, Jul 21, 2026 at 04:25:20PM +0200, Martin Husemann wrote:
> > One thing that might be broken since enabling IPv6 is the DNS server
> > itself - maybe your configuration has an IPv6 address for DNS lookups
> > now but the DNS server is broken.
> > 
> > Check /etc/resolv.conf for any IPv6 addresses.
> 
> Did dig, explicitly using @ for each DNS, it doesn't show AAAA record.
> 
> I have no /etc/hosts entry, like one wouldn't for github.
> 
> ping6 still goes like this:
> 
>     16 bytes from 2a06:98c1:3121::3, icmp_seq=0 hlim=54 time=4.323 ms
> 
> 
> For the git problem I worked around using -4 option for now. But curious
> about how ping6 resolves it (and so do others).

Try `getaddrinfo github.com'.  The getaddrinfo(1) tool will more
closely reflect what applications will observe.

While dig(1) examines only /etc/resolv.conf to do DNS queries,
getaddrinfo(1) respects /etc/nsswitch.conf for any kind of name
resolution, including DNS, mDNS, /etc/hosts, and anything else for
which there might be an nss_*.so module.

You might also ktrace ping6 to see what files it examines or network
traffic it exchanges.