I'm wanting to send only certain traffic across L2L VPN, not everything. The setup is from my home (ASA5505) to the main office (ASA5510). For example, I'd like to send all SSH traffic from my LAN across the VPN. I've tried setting this up with ACL's defining interesting traffic but seem to have no luck with this. I'm suspecting you can only send all or nothing across the VPN between subnets. For example:
LAN 1: 192.168.1.0/24
access-list VPN1 extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0
access-list VPN1 extended permit tcp 192.168.1.0 255.255.255.0 any eq 22
No-NAT is setup between 192.168.1.0 and 192.168.2.0
access-list VPN2 extended permit ip 192.168.2.0 255.255.255.0 192.168.1.0 255.255.255.0
access-list VPN2 extended permit tcp any 192.168.1.0 255.255.255.0 eq 22
No-NAT is setup between 192.168.2.0 and 192.168.1.0
This is what I have defined as interesting traffic for the VPN. I can communicate between LAN's with no problem, but SSH traffic is not being routed across the VPN. So when I SSH to 68.42.x.x, the SSH traffic is going out LAN1's default gateway and not across the VPN. I've ran a packet-trace to confirm this. Is it even possible to be selective as to what is routed across a VPN at the protocol level?
If you would like to SSH from your home network towards your HQ ASA, then you can SSH to the ASA inside interface ip address as it is already defined as part of the interesting traffic for VPN.
On the HQ ASA, you would need to configure the following:
In regards to your question on crypto ACL, typically you would only configure "IP" between the 2 subnets to define interesting traffic. If you would like to restrict only to allow SSH traffic from home network towards office network, then you would use ACL applied to the inside interface to restrict the access.
However, if I understand your requirement correctly, you would like to SSH to the HQ ASA from your home network via the VPN tunnel, then the above commands will allow SSH to the HQ ASA inside interface ip address.
Hope that helps.