[dns-operations] High IPv6 latency between a.root-servers.net and AS3320

[Sebastian Wiesinger]

Hello,

we noticed a high latency when querying a.root-servers.net from
AS3320 over IPv6.

These are the graphs we get for IPv4 and IPv6:

https://www.karotte.org/pics/a-root-AS3320-v4.png
https://www.karotte.org/pics/a-root-AS3320-v6.png

As you can see IPv4 latency is around ~12ms and IPv6 latency is around
200ms with up to 600ms and packetloss at (I assume) peak times.

Querying the hostname via IP6 gives me "rootns26-fra1" or
"rootns23-fra1" while querying via IPv4 gives "rootns20-fra1" or
"nnn1-fra1" which suggests IPv6 should still be Frankfurt.

A traceroute doesn't help much:

traceroute to 2001:503:ba3e::2:30 (2001:503:ba3e::2:30) from 2003:61:4002::2, 15 hops max, 24 byte packets
 1  2003:61:4002::1 (2003:61:4002::1)  3.592 ms  4.16 ms  1.477 ms
 2  * * *
 3  xe-1-1-0.r1.bb-fo.sfo1.vrsn.net (2001:504:d::c1)  169.598 ms  165.617 ms  167.042 ms
 4  xe-0-2-0.r2.bb-fo.sfo1.vrsn.net (2620:0:5050:fa01::96)  164.333 ms  185.201 ms  160.947 ms
 5  xe-1-2-0.r2.bb-fo.lax2.vrsn.net (2620:0:5050:fa01::7d)  176.661 ms  174.751 ms  175.169 ms
 6  xe-1-1-0.r2.edge-fo.lax2.vrsn.net (2620:0:5050:fa02::56)  180.437 ms  174.502 ms  174.655 ms
 7  * * *
 8  * * *

I assume some sort of routing weirdness but can't find out more... I
hope someone here can help in sorting this out.

Best Regards

Sebastian

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