i am a lil confused...
we have a Crypto ipsec / isakmp VPN tunnel setup from one router in the head office(loopback address) to the other router at the branch office(loop back address).
Ospf routes are also configured.. and hello packets are being recieved at both ends.. i can see them on the router.
the tunnel is set using dynamic crypto map. and allows LAN to LAN communication (defined in the ACL)
my question.. i can understand that the traffic sent in the VPN tunnel is the traffic defined in the ACL (lan to lan) and the OSPF routes are sent to each peers on the wan link..
then where do we make use of GRE ??
if i want to configure EIGRP between the two routers can i do so ??? while having a VPN tunnel between LAN to LAN
these WAN to WAN connections are point to point radio links. Theres is also a DSL connection for backup.
right now ive configured vpn session using the WAN ip addresses as peers.
and allowed LAN1 to LAN2 and vice versa in the ACLs.
i wana use the DSL line as backup, how do i configure that incase the radio link breaks.
(the wan end interfaces are fastethernets) so i cant go for static routes.. probably OSPF ?? or EIGRP ?