FWand VPN device behind exisitng ASA

sushil · ‎09-23-2009

Hi,

Existing setup is something like this.

ISP-->Router-->ASA(Nat)-->Internal $ DMZ.

All is working well.The Static nat is done on few of the public ip with private and placed in dmz.

Now my requirement is that i want to extend the network beyond dmz something like below.

ISP-->Router-->ASA(Nat)-->DMZ-->F/W+VPN device.

Want to have one more f/w+vpn device in my dmz.And wanted this firewall to do further nat and ipsec tunnel for the network behind that.I am sure if the natted static ip in dmz at ASA is 172.120.40.10 then definitley needs to feed this into outside int of new f/w+VPN.

Will this work or not?Do we need to change something in the existing ASA like (nat0)as static nat is happening on it for this particular natted ip which we going to use for ipsec traffic.

Can I use other free int on my existing ASA and use public ip on new fw+vpn device or not instead of 172.20.40.10?

Reg,

Sushil

andrew.prince · ‎09-24-2009

What you want to do is quite easy - but you must get your IP addressing correct.

the new FW/VPN device in the DMZ must/SHOULD have it's outside interface on the DMZ IP subnet - this will make the NAT simple to implement and troubleshoot.

What ever NAT you perform after that is either not required, if it is - then it will be simple.

I would suggest that you have a static 1:1 NAT for the new FW/VPN device in the DMZ to the true outside - things like ESP/AH generally do not like port forwarding.

HTH>

sushil · ‎09-25-2009

Thanks Andrew for this.I will give it a shot.

Reg,

Sushil