Hello there. I am rather new at this, but I spent quite some time on it with not much of a result so far. Here's the situation : I have setup a site to site VPN between a Cisco 1721 and a Cisco 857. The tunnel comes up, and I can do some things accross it, like :
- from a machine in LAN A, I can ping the interface of the other router in LAN B.
- I can do the opposite as well.
- but, when I ping a machine of LAN B from a machine of LAN A, only the first packet comes back ! This is also true if I ping A from B. If I wait a couple minutes, I can do it again, and with the same result : first packet gets an answer, not the others!
For those interested in the problem, here are sanitized configs :
On the 857 side :