Hi, we've just implemented a Dual DMVPN solution and have approx 3 * spoke pilot sites running at the moment for testing (all ADSL/SDSL).
We have the DMVPN setup with GRE tunnels and using EIGRP across the dual tunnels. Each remote site also has ISDN backup using the Dialer-Watch feature. All seems to be working ok with tunnel failover and routing etc.
However, we have noticed that our Spoke routers lose their EIGRP neigbours (to the Hubs) around the same time every 5-7 days and all initiate an ISDN backup call at the same time. The logs show the Hub EIGRP neighbour being lost for approx 1-3 minutes.
This seems to indicate that the Hubs are renegotiating something at this time every 5-7 days causing the spoke routers to lose their 'watched route' and bring up the BRI Dialer.
Are there any settings we need to make at the DMVPN Hubs to stop this happening..?
Do we need to change the EIGRP timers.?
Currently, EIGRP is set to the default timers of Hello's = 5 secs and Holdtime = 15 secs.
Appreciate any help here.