We have a 2811 in a remote location which connects to our core network using IPSEC tunnels over the Internet.
We have NTP configured pointing to four different servers. The servers are reachable from the router through the IPSEC tunnels no problem. We can trace to these NTP servers, and from these NTP servers without issue.
NTPO fils to synchronize with any of these servers. I have tried removing the confguration, confguring public NTP servers, but nothing works.
Debug NTP packets shows the packets being xmit'ted, but nothing returning, or rather nothing hitting the NTP listening port.
I'd appreciate any ideas here short of rebooting the router.