From libc.NEWS file:
Starting with version 2.9-8, unified IPv4/IPv6 lookup have been enabled
in the glibc's resolver. This is faster, fixes numerous of bugs, but is
problematic on some broken DNS servers and/or wrongly configured
firewalls.
If such a DNS server is detected, the resolver switches (permanently
for that process) to a mode where the second request is sent only when
the first answer has been received. This means the first request will
be timeout, but subsequent requests should be fast again. This
behaviour can be enabled permanently by adding 'options single-request'
to /etc/resolv.conf.
Could you try adding 'options single-request' in /etc/resolv.conf ?
From libc.NEWS file:
Starting with version 2.9-8, unified IPv4/IPv6 lookup have been enabled
in the glibc's resolver. This is faster, fixes numerous of bugs, but is
problematic on some broken DNS servers and/or wrongly configured
firewalls.
If such a DNS server is detected, the resolver switches (permanently
for that process) to a mode where the second request is sent only when
the first answer has been received. This means the first request will
be timeout, but subsequent requests should be fast again. This
behaviour can be enabled permanently by adding 'options single-request'
to /etc/resolv.conf.
Could you try adding 'options single-request' in /etc/resolv.conf ?