Too long Updating DMVPN(15min). Holdtime 10 , keepalive 10 3

[Ibrohim]

DMVPN come up 15min. has 225 routers. routing OSPF with default configuration (time).

It is too long us. How can I it faster?

[David Ruess]

Hello,

Based on the information you have given, if you are running OSPF over DMVPN then you most likely have all the routers (255 of them, as you say) in 1 area (if you don't then that may cause issues). That being the case then all 255 routes need to exchange topology information with each other and know about everyone else. This may be a huge routing table with updates. This could be the reason you are have having such convergence issues. Not to mention the LSUs have to travel to the HUB and then back down to each router for each router you have. Unless you have DMVPN Phase 2 or 3 configured. 

We would need to know more about the network. Can you share a topology diagram with HUB and a couple SPOKE configurations? OSPF configuration too?

You can also try using another routing protocol (EIGRP) to see if that helps any. However with 255 routers I assume this is a live network and will take a lot if time and planning.

-David

[MHM Cisco World]

what is network type you use broadcast or P2MP?

[Joseph W. Doherty]

You're asking about initial convergence time?

If so, holdtimes and/or keepalive times would have little impact, I suspect.

How OSPF is configured (as also touched upon by @David Ruess and @MHM Cisco World) matters!

Even with an "optimal" OSPF topology (which might also be painful to implement), as David also notes by mentioning EIGRP, another routing protocol might be a better choice.

Insufficient information to make better suggestions.