Stumped by this one so hoping one of the experts here has some ideas:
I want to configure a different route, for a specific destination subnet, for packets originating from a local process on the router vs. packets being forwarded from other hosts.
I’m familiar with policy routing and packet marking in general but can’t see how to do this. Looking at the packet flow diagram http://wiki.mikrotik.com/wiki/Manual:Packet_Flow I don’t see a place where packets can be marked before routing when the source is “local process out”.
My use case is as follows:
Router has an ethernet interface and a peer router through which its default route is configured as normal. It also has a second interface with a second peer router connected via a second ISP. My router is configured to connect a PPTP tunnel via this second ISP to a remote PPTP server. My goal is to ensure that traffic to the remote PPTP server is routed out the secondary interface, but only when the source is the local PPTP client. I want all other traffic being routed from other nodes on my network, with destination that same IP, to go out the primary interface (reason : the remote PPTP server also runs other services and I want to be able to access those through the fast primary ISP connection).
I am aware that I could use a set of filter rules to identify all the PPTP protocol traffic (TCP and GRE) for that destination IP, mark packets with the filter and configure a policy route to match. However, that would prevent other hosts on my network from making PPTP connections to the server via the primary ISP connection. If possible I would like to arrange for the secondary ISP connection only to be used for traffic originating on the Mikrotik router itself regardless of protocol.
Thanks.