Tunnel issue

[Robo123]

i have cisco 1921 router which was running "c1900-universalk9-mz.SPA.155-1.T1.bin" recently we have upgraded the same to"c1900-universalk9-mz.SPA.154-3.M8.bin" post same site to site tunnel is not working .

Please suggest on the above.

[Mark Malone]

Hi
did you diff the config between old an new since upgrade , some ios versions can remove lines of syntax that would be the first thing I would do , just happened me moving from standard ios-xe on 4k to denali , it took out my nhrp config broke my IWAN when I diffed it I could see the changes the upgrade removed 5

here's a portable diff tool if you haven't got it
http://www.softpedia.com/get/PORTABLE-SOFTWARE/Programming/Portable-ExamDiff.shtml