I have an ASA 5510 with a stic address and a 5505 with a dynmic.
I have created a dynamic VPN on the 5510. When the 5505 with it's dynamic address tried to connect with me I get the following errors:
Mar 25 05:45:14 [IKEv1]: IP = 184.108.40.206, Received ISAKMP Aggressive Mode message 1 with unknown tunnel group name '220.127.116.11'.
Mar 25 05:45:14 [IKEv1]: Group = DefaultRAGroup, IP = 18.104.22.168, Removing peer from peer table failed, no match!
Mar 25 05:45:14 [IKEv1]: Group = DefaultRAGroup, IP = 22.214.171.124, Error: Unable to remove PeerTblEntry
I also get a similar error when the 5505 has the Aggressive Mode disabled
It looks like the 5510 believes this is a L2L (site-to-site) connection request as opposed to a dynamically-established connection. It does not have a tunnel group for 126.96.36.199. You could create a tunnel group with that name to resolve this issue.
The other option is to set up the ASA's for a Remote Access (e.g., Easy VPN) connection.
Here is a URL describing how to set up L2L and Easy VPN with NEM. HTH