Why can only 1 side of the VPN tunnel initiate the traffic?

[ajwhite0]

Hello,

We have a VPN from the UK to Holland, we manage the UK side on a Cisco router, I don't know what they use in Holland.

Phase 1 and 2 work, but we can only initiate from the UK side.  So we had a report from a Dutch user who couldn't access a server in the UK and he was right as he couldn't ping it.  I got his IP and went onto the server and pinged back to him and the tunnel SA came up and I could eventually ping him and everything works.  Then after some time it goes down again I guess due to inactivity.

Now I have continuous pings running to their subnets to keep things up.

What should I check and get Holland to check?

Thanks

[MHM Cisco World]

Dynamic IPSec config without any Peer Set, the peer with this config can only accept IPSec traffic not initiate traffic.