I was having difficulties maintaining a VPN connection between two of our customer's stores. For reference, I have included the IPSEC configuration on the Cisco router at the bottom of this post. Notice that I am using hostnames and not IP addresses in this configuation. I have had mixed results with this type of configuration and this is related to my current problem. The router kept giving me the following error in the debug output: IPSEC: Peer myhostname.no-ip.biz's A record not found, lookup failure. What would cause such an error? I tried doing an nslookup from the command prompt on the myhostname.no-ip.biz address and it resolved fine. Is this a quirk of the Cisco router or is there something wrong with my configuration. Does anyone have any opinions on using hostnames versus static IP addresses in the IPSEC configuration? As an aside, I added the static IP address that myhostname.no-ip.biz currently resolves to as one of my peers and the VPN came up instantly. Any and all help is appreciated. Thank you.
crypto isakmp policy 1 encr 3des authentication pre-share group 2 lifetime 82800 crypto isakmp key 123 address 0.0.0.0 0.0.0.0 crypto isakmp key 123 hostname myhostname.no-ip.biz no-xauth crypto isakmp identity hostname crypto isakmp keepalive 60 5 periodic ! crypto isakmp peer address 0.0.0.0 ! crypto ipsec security-association lifetime seconds 82800 ! crypto ipsec transform-set ESP esp-3des esp-sha-hmac ! crypto map mymap 10 ipsec-isakmp set peer myhostname.no-ip.biz dynamic set transform-set ESP match address 101