I cannot RDP nor smb or access resources over an IPSec VPN tunnel between 2 Cisco firepowers, one is 1010 the other 1140
- I can ping fine both ways
- ACL not an issue as policy is to allow any port on both ends and ping works
- IPSEC configured on both towards Azure VPN gateway, and on both these tunnels RDP is possible
I suspect the MTU maximum session size is the culprit.. when I ping with packets less than 1350 (size changes, but varies between 1350 and 1400) I get the below response: ping -l 1400 192.168.1.1 -f ----> Packet needs to be fragmented but DF set
If so, how to configure the mss through Flexconfig Sysopt_basic ? there are no templates on the Firepowers.. and the CLI is too basic..
If not, what might be the issue?