Re: address pair exploration, flooding and state loss

[Iljitsch van Beijnum <iljitsch@muada.com>]

On 27-mei-2005, at 22:57, Erik Nordmark wrote:

> 2. The box reboots in 30 seconds. TCP retransmissions for the next  
> 10 minutes are silently dropped because the retransmissions arrive  
> at the peer's TCP with a bad checksum (due to "missing" shim6  
> rewrite).
> Thus any RST doesn't arrive until 10 minutes or so later!

Can we create a new ICMP message that says "I got a packet that may  
or may not have come from you and it had a wrong layer 4 checksum"?

Since the faulty checksum may be the result of a bit error, we  
probably don't want to copy back any data to the sender as it may not  
be the actual sender. But if the sender is shim capabable and has  
state towards the receiver, it can then send a shim-level state  
inquiry and the truth will come out.

On a slightly related note: it would be good if we can rebuild shim  
state after it has been lost on one side when at the same time, there  
is a failure. This would allow new sessions to be created and  
immediately rehomed that would otherwise have failed.