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New Member

IOS to ASA L2L - tunnel traffic only flows one direction

I have a L2L tunnel set up between an ASA5505 (branch office) and a 3825 router (HQ; IOS-advipsecurity feature set). The tunnel seems to always be up, but the problem is that traffic doesn't flow out to the branch unless traffic has already come in from the branch.

I'm pretty sure that the problem is on the router at HQ, as it does not seem to be properly routing traffic outbound over the tunnel to the branch. The branch has no problem communicating with the network at HQ. I do have keepalives enabled on both sides, but that doesn't seem to be making any difference.

All crypto configs are the same on both ends, and the tunnel completes Phases 1 and 2 no problem. My guess is that this is an ACL or NAT problem on the router. I am not used to configuring VPNs with an IOS router at the hub and an ASA at the spoke, so I would appreciate any guidance.

Relevant router config attached. Thanks in advance.

New Member

Re: IOS to ASA L2L - tunnel traffic only flows one direction


need to watch

show crypto ipsec sa three times 5-10 seconds interval from both sides

show ip route

show access-list