CentOS - Mar 2014 - 6.5 vpn/gre/ospf breakage

Hi List,

FYI.

We have been using CentOS 6.4 and have 2 vpn/gre tunnels to separate cisco rtrs
using ospf.
with kernel 2.6.32-358.23.2

We have upgraded to 6.5 bit using kernel 2.6.32-431.5.1 and the exact same
configuration scripts for
our vpn/gre tunnels.

What I see is the first gre tunnel works great and I get an ospf neighbor.

The second tunnel comes up and I can ping across it and I see our side sending
hello packets in the gre tunnel
but I never receive any hello packets from the cisco.

The cisco sees our hellos because it goes into the Init state. I do a tcpdump
and I see esp traffic coming from the cisco like it is sending hellos but they
never show up in a tcpdump
on the gre tunnel. It is like the kernel is not delivering them.

Also my gre tunnels on CentOS 6.5 are named gre1 at NONE and gre2 at NONE with
an ip a s, while on the 6.4 CentOS system
they show up as only gre1 and gre2?  Whats with the @NONE?

Looking at the Changelog of the kernel a lot of changes to the ip_gre module
were made in 2.6.32-380


-- 
Stephen Clark
*NetWolves Managed Services, LLC.*
Director of Technology
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark at netwolves.com
http://www.netwolves.com

On Thu, Mar 27, 2014 at 8:24 AM, Steve Clark <sclark at netwolves.com>
wrote:
> Hi List,
>
>
Hi Steve,

> FYI.
>
> We have been using CentOS 6.4 and have 2 vpn/gre tunnels to separate cisco
> rtrs using ospf.
> with kernel 2.6.32-358.23.2
>
> We have upgraded to 6.5 bit using kernel 2.6.32-431.5.1 and the exact same
> configuration scripts for
> our vpn/gre tunnels.
>
There was a brief thread (total of three posts) on multicast changes with
the newer CentOS 6 kernel.
http://lists.centos.org/pipermail/centos/2014-February/141062.html

Apparently something odd going on in 2.6.32-431.x.x -- functionality that
operates fine in the older 2.6.32-358.x.x kernels.

>
> What I see is the first gre tunnel works great and I get an ospf neighbor.
>
> The second tunnel comes up and I can ping across it and I see our side
> sending hello packets in the gre tunnel
> but I never receive any hello packets from the cisco.
>
> The cisco sees our hellos because it goes into the Init state. I do a
> tcpdump
> and I see esp traffic coming from the cisco like it is sending hellos but
> they never show up in a tcpdump
> on the gre tunnel. It is like the kernel is not delivering them.
>
> Also my gre tunnels on CentOS 6.5 are named gre1 at NONE and gre2 at NONE
with
> an ip a s, while on the 6.4 CentOS system
> they show up as only gre1 and gre2?  Whats with the @NONE?
>
> Looking at the Changelog of the kernel a lot of changes to the ip_gre
> module were made in 2.6.32-380
>
>
Sounds like you might be aware of the post I linked to above.
( In case you're not, I'll send this message anyways. )

>
> --
> Stephen Clark
> *NetWolves Managed Services, LLC.*
> Director of Technology
> Phone: 813-579-3200
> Fax: 813-882-0209
> Email: steve.clark at netwolves.com
> http://www.netwolves.com
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>


-- 
---~~.~~---
Mike
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