nat buzz
Switches actually do 2 types of forwarding:
- Forward the actual, unchanged IP datagram to a LAN where the cache is promiscuously listening
- Change the IP destination to the cache and route the modified datagram normally
If we overwrite the IP destination, we still need to know where the client wanted to go
- Some application-level protocols tell us
- If not, use TPACT to ask switch
Even with app headers, seems like we still need IP dest so we can forge the reply to the client!