I am encounter with 1841(IOS 12.4) router using with ospf over mGRE.
We are using Hub to Spoke technology. We are using 2 Hubs(2621 router)(primary-ethernet and backup-ISDN).
We have 8 spoke sites using with 1721(router) currently.
I want to migrate to 1841 router to one of the spoke. I configured like as old 1721 settings on 1841 new router. I can reach only 6 spoke sites. unfortunately I can't reach to 1 spoke site.(We can reach all spoke site using with old 1721 router.)
I don't know why I can't reach to one of the spoke.
IOS version of 7 spoke sites are IOS12.2(4)YA2) and one is the IOS 12.2(15)T10)that i can't reach.
Is there any issue on different IOS version on DMVPN method. ( I read from cisco website they mention before 12.0 IOS and after 12.0 IOS can't work together)
Pls drop me to any suggestion.