Network Troubleshooting - Cisco Packet Flow

To be or not to be.
Incoming or Outgoing Packets, sometimes understanding these two subjects are very vital in troubleshooting process.

ip access-list  extended gre-debug-out

permit gre any any log // optional 

permit ip any any log

ip access-list  extended gre-debug-in

permit gre any any log // optional

permit ip any any log

interface GigabitEthernet0/1

ip access-group gre-debug-in in

ip access-group gre-debug-out out


Here it is; 

show ip access-list gre-debug-in

show ip access-list gre-debug-out out

believe me you will like the result..

:)