I'm using a Cisco 881 router with IOS version (Cisco IOS Software, C880 Software (C880DATA-UNIVERSALK9-M), Version 12.4(24)T3,
RELEASE SOFTWARE (fc2)).
This router is used to connect a remote site (/24 network) to the company main site via a site 2 site VPN tunnel. In general the /24 network is on the LAN interface (vlan1) and the VPN tunnel is build up from the WAN interface. This works just fine.
Right now, we have a special situation and the goal is to use a Cisco 881 router doing the same just using a single interface (VPN on a stick).
In the following I will provide some more detail:
1) the remote network ist 192.168.1.0/24
2) the vlan1 interface address is 192.168.1.2
3) the DSL router IP address is 192.168.1.1
4) IP addresses 192.168.1.10 to 192.168.1.254 is used by the clients (subnet 255.255.255.0, gateway 192.168.1.2)
5) main site network 10.10.0.0/16
Could anybody tell me if this is possible? If so, could you please provide details how to do that and/or a sample configuration?
Thanks for your help.