Question about GRE Tunnel

[cabrademonte]

Hi guys,

I have a question about how a packet behave's with GRE tunnel's. If rouer A  send a ping to router B  and the ping goes through the tunnel what will the router do for the ip source and ip destination information, will it change it or encapsulated to the tunnel source and tunnel destination

Output

interface tunnel 0                       interface tunnel 0
ip address 1.1.1.1 255.255.255.240       ip address 1.1.1.2 255.255.255.240
tunnel source 128.8.8.8                  tunnel source 129.9.9.9
tunnel destination 129.9.9.9             tunnel dest...

[Mohamed Sobair]

Luis,

If router A pings router B for addresses routed through th tunnel. The IP packet will be encapsulated with a GRE Header , this header is only deencapsulated at the GRE tunnel end to reach its deired destination.

So, No matter what do you have between 2 GRE tunnels in between, the packet traversing the tunnel is not revealed because its encapsulated while the packet is forwarded to the destination.

Hope this helps, Let me know if this addressed you enquiry,

Mohamed

[cabrademonte]

Sorry for the late response but thanks. It help