On Thursday 12 January 2023 at 16:15:59, Eli Taft wrote:
> I have two Debian servers on EC2 instances in AWS.
> One server is attempting to connect using IPv6 first, and only when all of
> those time out does it try and succeed to download using an IPv4 address.
> The other server doesn't do this... it just using IPv4 and downloads
> instantaneously.
> Both of these servers are using the same network / vpc settings too.
The first thing I would test is whether both servers can resolve a hostname
which has both IPv4 and IPv6 addresses, and whether they can both connect to
each address.
My suspicion is that one is (mis?)configured with an IPv6 address, and therfore
tries to use IPv6, which then fails, and the other server doesn't even have an
IPv6 address (or route?) and therefore just goes for IPv4 immediately.
For example, this is what I get on one of my (not AWS) machines:
$ ping4 -n google.com
PING google.com (172.217.16.206) 56(84) bytes of data.
64 bytes from 172.217.16.206: icmp_seq=1 ttl=57 time=10.2 ms
64 bytes from 172.217.16.206: icmp_seq=2 ttl=57 time=10.3 ms
64 bytes from 172.217.16.206: icmp_seq=3 ttl=57 time=10.2 ms
$ ping6 -n google.com
PING google.com(2a00:1450:4001:806::200e) 56 data bytes
64 bytes from 2a00:1450:4001:806::200e: icmp_seq=1 ttl=57 time=10.3 ms
64 bytes from 2a00:1450:4001:806::200e: icmp_seq=2 ttl=57 time=10.3 ms
64 bytes from 2a00:1450:4001:806::200e: icmp_seq=3 ttl=57 time=10.3 ms
Antony.
--
3 logicians walk into a bar. The bartender asks "Do you all want a drink?"
The first logician says "I don't know."
The second logician says "I don't know."
The third logician says "Yes!"
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