Cisco site to site VPN

matedwards used Ask the Experts™

I need to set up a site-to-site vpn between two Cisco 877 ADSL modem/routers.
As is very common with Cisco the GUI utilities (SDM, SDM express) don't work.. both boxes will have a static xxxx.xxxx.xxxx.xxxx WAN IP address and with 10.10.0.xxxx/24 and 192.168.4.xxxx/24 LAN subnets at either end.

Can anyone help with the commands to do it in the CLI or even a text file with an example in..?

Any help would be greatly appreciated..?

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here is a standard ipsec solution. the access list will have to be modified to have he correct ip address range. if you don't want this type of tunnel and your router will support it i would say do a GRE tunnel with protection on. If you want i can post that if you don't like this solution.

point to point ipsec-tunnel

crypto isakmp policy 1
 encr 3des
 authentication pre-share
 group 2
crypto isakmp key (secret) address (address)
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto map IPSEC 1 ipsec-isakmp
 description Tunnel to (something)
 set peer (address)
 set transform-set ESP-3DES-SHA
 match address 107
int fa0/0
 ip address (ip) (mask)
no shut
ip nat outside
crypto map IPSEC

route-map RMAP_1 permit 1
 match ip address 104

ip nat inside source route-map RMAP_1 interface fa0/0 overload

access-list 104 deny   ip
access-list 104 permit ip any
access-list 107 permit ip



thanks cosmicfox..

What would be the advantage of a GRE tunnel with protection on..?

gre allows you to put routing protocol traffic over the vpn, along with other advantages. here is a link to it, if your router supports it.
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Thanks agaoin cosmicfox.. we have reset the Cisco 877 to factory defaults and now cannot access either box.. Cisco have insisted we take out a service contract, costing £1000s, to send us the firmware the units came with..??!!
 We are inches away from binning them both and buying a couple of Netgear.. I may have to abandon this question.. apologies again.. will post shorty..
how did you reset it? if you erased the startup config only then you don't need the firmware. Cisco will want a contract in order to help you. Can you get into the device via the console port? it's fine if you decide to switch there is a slight learning curve for cisco.



Thanks cosmic.. we managed to get some firmware off of our Cisco reseller.. we imported your text using the CLI and saved it to the startup config..  it then appeared in the Cisco SDM and we could see the entries.. the subnets can't ping each other at either end but the tunnel is up and that is another question.

thanks again..

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