[ovs-discuss] packets getting dropped at egress

[gowrishankar]

On Thursday 23 July 2015 04:16 AM, Dave Waters wrote:
> Hi,
>
> I have two ports in my OVS bridge. I receive packets from one port 
> (portA) and i send them out of the other (portB). When i send out the 
> packets, they are VXLAN tunneled to the other end.
>
> Now, the default MTU of all ports (including the bridge port) is 1500 
> in my setup.
>
> The issue is that when i get a 1500 byte packet on portA, i try to 
> push it out on portB after slapping on the VXLAN headers. This results 
> in a packet size thats greater than what portB can handle, and hence 
> the packets are dropped.
>

Is increasing MTU of portB to 1550 (to accommodate additional 50 bytes 
when no vlan taged) a constraint in your setup ?

> I know that OVS does not handle IP fragmentation/reassembly, so how do 
> we deal with this situation? I dont think we can rely on path MTU 
> discovery since not all applications do PMTU before spewing out 
> packets. Any ideas, anybody?
>
> Warm regards,
> Dave
>

-- 
Regards,
Gowrishankar M