[lvs-users] IPv6 broken in 3.9 kernel? (UNCLASSIFIED)

Kash, Howard M CIV (US) howard.m.kash.civ at mail.mil
Wed Jun 19 13:45:53 BST 2013

Classification: UNCLASSIFIED
Caveats: NONE

It appears to be an IPv6 routing issue rather than an IPVS issue.  With the 3.8.8 kernel, the following routes to the real servers appear automatically in the routing table:

2001:x:x:x::30/128  2001:x:x:x::30 UC 0  694882451  2 bond0
2001:x:x:x::40/128  2001:x:x:x::40 UC 0  695098682  2 bond0
2001:x:x:x::50/128  2001:x:x:x::50 UC 0  870214     2 bond0

With the 3.9.3 kernel these route do not appear, and attempts to send DNS queries to the real server from the load balancer give "no route to host" errors.  Manually adding routes fixes the issue:

route -A inet6 add 2001:x:x:x::30/128 gw 2001:x:x:x::30 dev bond0
route -A inet6 add 2001:x:x:x::40/128 gw 2001:x:x:x::40 dev bond0
route -A inet6 add 2001:x:x:x::50/128 gw 2001:x:x:x::50 dev bond0

This seems like a kludge, but I haven't figured out what the root cause of the issue is.


-----Original Message-----
From: Julian Anastasov [mailto:ja at ssi.bg]
Sent: Wednesday, June 19, 2013 5:10 AM
To: Kash, Howard M CIV (US)
Cc: lvs-users at linuxvirtualserver.org
Subject: Re: [lvs-users] IPv6 broken in 3.9 kernel? (UNCLASSIFIED)


On Tue, 28 May 2013, Kash, Howard M CIV (US) wrote:

> Classification: UNCLASSIFIED
> Caveats: NONE
> After upgrading kernels from 3.8.8 to 3.9.3, IPVS will no longer forward IPv6 DNS packets (UDP or TCP) to the real servers.  IPv4 works with the 3.9.3 kernel.  Booting back to the 3.8.8 kernel resolved the IPv6 issue.  Any ideas?

        Do you still see this problem? I'm not using
IPv6, may be others can help here.


Julian Anastasov <ja at ssi.bg>

Classification: UNCLASSIFIED
Caveats: NONE

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