1. Home
  2. Cisco Systems
  3. setting up a VPN tunnel with overlapping private IP addresses on Cisco ASA

setting up a VPN tunnel with overlapping private IP addresses on Cisco ASA

Hi, everyone

I was wondering if you guys could give me a hand with something. I have a client who needs to set up a secure VPN tunnel between his ASA

5520 and a PIX 515 for another company in order to give 2 specific computers on each side access to each other.

The problem is, on each side, the IP addresses are the exact same. Example: 1 computer on each side has the IP address 10.10.10.1/16, and the other computer on each side has 10.10.10.2/16, thus causing an overlap.

I want to be able to set up a VPN tunnel on each side to give each machine access to the other. I cannot install a router behind either firewall (as the client doesn't have a spare).

I had thought of NATting the client's private range addresses of

10.10.10.1 and .2 to a single public address (which the client is able to supply me with), then establish a VPN tunnel on each side only publishing the public IP address through the tunnel. On each side, rules would be set up so that any queries to that specific public address would be directed to the appropriate private IP address. Each machine would only send queries to the public IP address. The only problem is, I'm not exactly sure how to configure it.

Does anyone have an idea how to configure this?

Thanks very much!

Reply to
Mike Rahl
Loading thread data ...

Do it exactly as you would using private IP's, but don't include a NAT

0 statement, and use public IP's in your interesting traffic statements. Here's a sample of what you need (Not sure about the ASA b/c it runs PIX OS 7.x)

access-list VPN_ACL permit ip host

! This static may or may not be needed. If not, then the workstation ! will use the NAT pool or PAT as defined, and the remote VPN box ! will need to know this pool in it's interesting traffic ACL.

static (inside,outside)

Reply to
response3

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.