[AusNOG] MTU debugging? (Or possibly just a fault with Amazon SES?)

[Jeremy Visser]

On 03/06/15 14:47, Damien Gardner Jnr wrote:
> But sure enough, as expected the router IS sending the correct ICMP reply back to amazon:
> 
> However the next packet in is then again over sized:
> 
> So the router again sends a frag needed:
> 
> And what do you know, another packet that is too large?

To me that looks like Amazon are ignoring your ICMP "frag needed" message, and as such their TCP is retransmitting over and over until timeout.