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IPv6 routing loop in Kimsufi


ned14
06-15-2012, 02:51 PM
Turns out this is a partial mea culpa. The Proxmox 2.x template which OVH provides is based on Debian squeeze, and Debian squeeze comes with a faulty bridge-utils which borks IPv6 config on a network bridge. As Proxmox uses vmbr0 as its basic network device, this effectively disables IPv6 connectivity on all Proxmox 2.x installations on OVH/Kimsufi.

Here's how to fix. Edit /etc/network/interfaces and go down to where it auto vmbr0:

Code:
auto vmbr0
iface vmbr0 inet static
        address 91.xxx.xxx.xxx
        netmask 255.255.255.0
        network 91.xxx.xxx.0
        broadcast 91.xxx.xxx.255
        gateway 91.xxx.xxx.254
        bridge_ports eth0
        bridge_stp off
        bridge_fd 0
        # Something is borked with IPv6 bridging, so manually ...
        post-up ip -6 ro add 2001:xxxx:1:b1ff::/64 dev vmbr0
        post-up ip -6 ro add default via 2001:xxxx:1:b1ff:ff:ff:ff:ff dev vmbr0
        pre-down ip -6 ro del default via 2001:xxxx:1:b1ff:ff:ff:ff:ff dev vmbr0
        pre-down ip -6 ro del 2001:xxxx:1:b1ff::/64 dev vmbr0
iface vmbr0 inet6 static
        address 2001:xxxx:1:b16b::1
        netmask 64
        gateway 2001:xxxx:1:b1ff:ff:ff:ff:ff
        bridge_ports eth0
        bridge_stp off
        bridge_fd 0
This is a combination of the Proxmox defaults and the IPv6 config instructions from http://help.ovh.co.uk/Ipv4Ipv6. The fix is after the "Something is borked" comment. What it does is to add a route to the multicast for your IPv6 space, and then set the default IPv6 gateway to your gateway. bridge-utils should do this for you, but it doesn't, so the above accomplishes the same.

Note that your gateway is always your IPv6 address with 00FF set after the /64 i.e. 1111:2222:3333:4444:5555:6666:7777:8888 would turn into 1111:2222:3333:44ff:ff:ff:ff:ff.

Happy IPv6ing!

Niall

Jane
06-15-2012, 12:28 PM
Hi Ned

I can see that the incident was replied to yesterday. When it comes to incidents they're dealt with on a first come first served basis, unless you have paid for the VIP service.

If you have any further issues, you're better off replying through the incident ticket or emailing support.

All the best

Jane

OVH team

ned14
06-08-2012, 11:19 PM
Hi,

I submitted this as an incident no 1032077 on 21st May but there has been no movement at all since then. Can you give whoever is assigned a poke for me please? I can confirm that today 8th June this IPv6 routing loop is still happening, and there is no IPv6 connectivity in or out of my server at all.

Thanks,
Niall


From : DN12829-OVH
For: OVH Help desk
Date: 2012-05-21 15:48:16
Looks like there is a routing loop in the IPv6 routing to
my server. I have copied and pasted the message from your
support asking me to open this incident ticket.

[below is from support dialogue]
--- cut ---

Hello,

Yes, it looks like there's a configuration issue. Please
open an incident ticket. Connect to your manager:
https://www.ovh.ie/managerv3/

And then click your server name > Contact our support >
Submit an incident ticket. After network administrators
will check your issue.

Regards,
Gytis
OVH

> Can I confirm that IPv6 routing to my server on
2001:41d0:1:b16b::/64 is working correctly?
>
> It looks from a traceroute that there is a routing loop
at OVH:
>
> traceroute6 to ipv6.europe3.nedproductions.biz
(2001:41d0:1:b16b::1) from 2002:57e8:4c29::, 64 hops max,
12 byte packets
> 1 * * *
> 2 2001:4d68::385 85.887 ms 87.798 ms 89.875 ms
> 3 DN07-ae1-233-ibis-dc-2.irishbroadband.ie 80.098 ms
79.322 ms 82.002 ms
> 4 DN07-ae1-5-ibis-dc-1.irishbroadband.ie 86.059 ms
85.552 ms 87.900 ms
> 5 DN07-ae0-2-ibis-gw-1.irishbroadband.ie 88.238 ms
85.652 ms 85.889 ms
> 6 ge-1-1-0-19.dub10.ip6.tinet.net 85.939 ms 87.566 ms
85.934 ms
> 7 xe-5-3-0.lon11.ip6.tinet.net 80.124 ms 79.313 ms
> xe-10-1-0.lon11.ip6.tinet.net 84.047 ms
> 8 as6453.ip6.tinet.net 268.148 ms 212.980 ms 313.884
ms
> 9 if-13-1-0.mcore3.LDN-London.ipv6.as6453.net 80.077
ms 79.667 ms 77.782 ms
> 10 if-xe-1-1-1.0.tcore1.L78-London.ipv6.as6453.net
78.070 ms 117.663 ms 75.845 ms
> 11 if-ae5.2.tcore1.PYE-Paris.ipv6.as6453.net 78.004 ms
79.520 ms 80.012 ms
> 12 if-ae2.2.tcore1.PVU-Paris.ipv6.as6453.net 82.055 ms
75.502 ms 78.092 ms
> 13 * * *
> 14 th2-g1-a9.fr.eu 84.691 ms 91.431 ms 88.210 ms
> 15 rbx-g2-a9.fr.eu 87.853 ms
> rbx-g1-a9.fr.eu 89.606 ms
> rbx-g2-a9.fr.eu 87.414 ms
> 16 rbx-1-6k.fr.eu 89.566 ms
> rbx-2-6k.fr.eu 85.869 ms
> rbx-2-6k.fr.eu 87.894 ms
> 17 * * *
> 18 * * *
> 19 * * *
> 20 * * *
> 21 * * *
> 22 * * *
> 23 * * *
> 24 * * *
> 25 * * *
> 26 * * *
> 27 * * *
> 28 * * *
> 29 * * *
> 30 * * *
> 31 * * *
> 32 * * *
> 33 * * *
> 34 * * *
> 35 * * *
> 36 * * *
> 37 * * *
> 38 * * *
> 39 * * *
> 40 * * *
> 41 * * *
> 42 * * *
> 43 * * *
> 44 * * *
> 45 * * *
> 46 * * *
> 47 * * *
> 48 * * *
> 49 * * *
> 50 * * *
> 51 * * *
> 52 * * *
> 53 * * *
> 54 * * *
> 55 * * *
> 56 * * *
> 57 * * *
> 58 * * *
> 59 * * *
> 60 * * *
> 61 * * *
> 62 * * *
> 63 * *^C
>
> Thanks,
> Niall
>