We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you two Citrix podcasts. Learn about 2020 trends and get answers to your biggest Citrix questions!Listen Now

x

Site to Site VPN with PIX/Cisco 800 series router - One side has dynamic IP

itdeptneci
itdeptneci asked
on
Medium Priority
666 Views
Last Modified: 2012-05-06
Hi,

I'm looking for a config example of how to setup a Site to Site VPN using IPSec and Pre-Shared key, where one side uses a dynamic ip address.  The PIX uses a static address, however the Cisco 800 series is used with a dynamic ip address.

The default VPN site to site tunnel on the PIX requires a Peer IP address, which I cannot supply due to having dynamic address at the other side.

I read one other post stating that the PIX requires a dynamic-map instead of a peer-ip, but I cannot find any actual working examples.

Your help would be much appreciated!

Below is an example config that is used for an existing tunnel working over fixed IP.  If I can modify one of these using IOS to work using dynamic-map, this would be ideal.

PIX side

access-list outside_cryptomap_141 extended permit ip 192.168.1.0 255.255.255.0 1
92.168.104.0 255.255.255.0

crypto map outside_map 141 match address outside_cryptomap_141
crypto map outside_map 141 set pfs
crypto map outside_map 141 set peer x.x.x.x
crypto map outside_map 141 set transform-set ESP-3DES-SHA

tunnel-group x.x.x.x type ipsec-l2l
tunnel-group x.x.x.x ipsec-attributes
 pre-shared-key *

Cisco 800 side

crypto isakmp policy 1
 encr 3des
 authentication pre-share
 group 2
crypto isakmp key * address x.x.x.x

crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
!
crypto map SDM_CMAP_1 1 ipsec-isakmp
 description Tunnel tox.x.x.x
 set peer x.x.x.x
 set security-association lifetime seconds 28800
 set transform-set ESP-3DES-SHA
 set pfs group2
 match address 102
access-list 102 remark IPSec Rule
access-list 102 permit ip 192.168.104.0 0.0.0.255 192.168.1.0 0.0.0.255

Thanks,

Kevin
Comment
Watch Question

Top Expert 2010
Commented:
Config example is right here:

http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a00805733df.shtml

At my current employ, I have 8 sites using dynamic IPs to hit the HQ's ASA.  It works well with the understanding that only the remote site can initiate the tunnel.  

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts

Author

Commented:
Hi,

Yes about 2 minutes after posting I came across the following and its now working!

http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_configuration_example09186a00807ea936.shtml

One question though regarding your 8 sites.

Are each of your tunnels using the same pre-shared-key, and tunnel group?

Thanks!
Top Expert 2010

Commented:
Yes they are.  
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.