I've got a PIX running 7.2(4) with its outside interface on the Internet. The only thing this PIX is doing is acting as the endpoint for an IPSEC LAN-to-LAN tunnel with an Internet-connected ASA on another network.
I'd like to filter inbound Internet traffic to this PIX so that only the designated ASA can attempt to establish an IPSEC connection -- in other words, I want to prevent any other device on the Internet from even being able to attempt to establish an IPSEC connection to the PIX. As far as I know (and have seen), this can't be done with an access-list on the outside interface, since that access-list doesn't apply to traffic to the PIX itself.
So: is this possible, and if so how?
I dont know about PIX and the old software.
In the new software its possible to create and separate ACL to filter for example traffic which will prevent ISAKMP towards the local "outside" interface.
The new softwares lets you use the keyword "control-plane" in the "access-group" command
Heres a link for your reference on the Command Reference of 9.1 software level (not sure when the command parameter was introduced but I think its pretty new)
Since you dont have an Internet router in between I guess you cant really block the Phase1 there either. Is there a possiblity that the ISP could do this for you?
EDIT: Stupid typos