Im having problem with GRE tunnel connecting cisco and mikrotik routers, have tried many different configurations but none seems to work,
tried disabling firewall rules on mikrotik, tried to turn off keepalive on mikrotik gre, tried to keep it on and configured same keepalive on cisco but still didnt work, tried with ipsec but no results.
also tried adjusting MTU to first 1476 then 1400 on both ends but still nothing
currently im just trying to get gre in up state, configuration is really simple
interface tunnel 1
tunnel source 22.214.171.124
tunnel destination 126.96.36.199
ip address 10.10.10.1 255.255.255.252
same on mikrotik
on both routers GRE is easily up when its connecting to other devices, i have tried mikrotik to mikrotik and cisco to other mikrotik and works perfecting also on these routers there are currently many tunnels that are working fine....