I made a quick screencast of how to set this all up, which you can view here. For quick reference I include a test guide below. Enjoy!
– Everything to left of the sonicwall is virtualized
– You need to create two loopback adapters:
Loopback # 1 : call this “to physical”
Loopback # 2 : call this “to virtual”
– Bridge “to physical” to the physical interface (be careful, you can only use bridging once in the windows OS. It also slows down the net connection… so use it wisely)
– Install GNS with IOS images
– Setup the following:
Where:
C0 is bound to the “to physical” loopback adapter
C1 is bound to the “to virtual” loopback adapter
-Configure both interfaces of the cisco as you desire
-Configure routing on both the cisco and sonicwall to prevent IP spoofs
– Install VirtualBox
– Install the two images of ubuntu
– Bridge the ubuntu machines to the “to virtual” loopback
– Setup the IP config of the machines as per usual
– At this point, the cisco should be able to ping sonicwall and the internet with no problems
– However, ubuntu machines should be able to ping cisco only.
– When trying to ping ubuntu -> WAN, ping request paths correctly, but reply goes over to the physcial interface of the bridge rather than over the logical interface of the bridge from where it came from
– Add a static route on the physical interface to point to the cisco š
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