BGP flapping while peering with Cisco ASR - Hold timer expired error

[Martin Kraus]

On Wed, Apr 03, 2013 at 11:15:27AM +0800, Jimmy Halim wrote:
> >Does the bgp session establish?
> [Jimmy] Yes
> >Do the routers finish exchanging routing information?
> [Jimmy] Nope, we did not receive any routes
> >Which router is hitting the hold time?
> [Jimmy] Both sides
> >Did the same machine work with your old routing daemon against the same
> >ASR 
> >before switching to bird?
> [Jimmy] Yes, old machine running openbsd and OpenBGPd as routing daemon.
> New server is running centos and BIRD as routing daemon
> >Did you do any other changes to it while switching to bird?
> [Jimmy] No

Can you dump the tcp bgp session on the centos? What happens after the bgp
session establishes? If it doesn't exchange routes and the holdtimer is hit
then there should be no tcp traffic. 
Is the MTU on both sides the same and can the layer 2 support it? 
Martin