Mangle with Routing Mark breaks communication

Hi Guys,

Forgive me if there is a similar question that has been asked, I have done the google route but cannot seem to find and answer.

I am trying to configure Routing Marks using Mangle for a network range, but I seem to be losing connectivity to that range when I do this.

My setup is as follows:

Mikrotik RB951-2n running OS 6.33.3
Ether 1 is the internet breakout
Ether 2 has an IP Address range of 192.168.x.x/24 and Ether 3 has an IP Address range of 172.16.x.x/24

I have a machine on IP 192.168.x.xxx which I am successfully marking the route using the following

add action=mark-routing chain=prerouting comment=“Mark all connections destined for VPN Tunnel” new-routing-mark=VPNTraffic src-address-list=VPN

That all works fine, the packet gets marked and routed through the VPN as expected. I can still access this server it’s IP Address via SSH as it is a Linux system.

However if I try add another mark as follows:

add action=mark-routing chain=prerouting comment=“Mark all connections destined for VPN Tunnel” new-routing-mark=VPNTraffic src-address=172.16.x.x/24

I can no longer access the laptop that has been given an IP Address of 172.16.x.x, when I disable the Mangle I can get access again. IS there something I am missing?

I suspect it is something small and may be related to routing as it might try route the response packets to the VPN, which is not what I am wanting, I need it to route through the VPN, but I need to be able to VNC or SSH into the laptop as well.

any assistance is greatly appreciated. Hope it all makes sense..

Regards
Andrew Downs