> In the first, if Alice served by Bob and Bobby, it is probable that
> Alice's administration lists both the Alice-via-Bob and the Alice-via-
> Bobby address in DNS. If Carol seeks to connect to Alice, Alice will
> pick among those addresses at random unless she has a good explicit
> reason to have an affinity to one of them. However, routing within
> Alice's network may choose a different exit gateway than the ingress
> gateway Carol in effect chose when she chose an address to use for
> Alice. Thus, when Carol sends a SYN to Alice-via-Bob, the SYN-ACK
> might come from Alice-via-Bobby. One hopes that Carol would eventually
> retry Alice-via-Bobby and get through.

It can get even worse is Carol is served by Dan and Danny. In the worse case, 
we get something like:

1) Carol sends a SYN to Alice-via-Bob. It gets routed through Dan, because of 
local preferences at Carol's network.
2) Alice sends a SYN-ACK to Carol-via-Dan. It gets routed through Bobby, due to 
local preferences at Alice's network.
3) Of course, the SYN-ACK gets dropped by the NAT66-via-Dan entry point in 
Carol's network.
4) Carol retries, sends a SYN to Alice-via-Bobby. It gets routed through Danny, 
because of local preferences at Carol's network.
5) Alice sends a SYN-ACK to Carol-via-Danny. It gets routed through Bob, due to 
local preferences at Alice's network.
6) Tough luck, uh..

-- Christian Huitema



_______________________________________________
nat66 mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/nat66

Reply via email to