PPTP server on alternative routing table fails when client is not reachable via main routing table

Hi,

\

  • Have a PPTP server running on 6.27
  • Some sessions that come in via a certain interface also need to go back out through that interface
  • Works fine with mangle/routing marks.
  • However if the main routing table (which is not used here) does not know the destination, ROS will drop the response packets before I have any chance to modify the routing mark.

So the simple solution would be to add a dummy unreachable/blackhole route to the main table, right?
Doesn’t work either:

> ping 1.2.3.4 routing-table=alt 
  SEQ HOST                         SIZE TTL TIME  STATUS           
    0 1.2.3.4                              56  49 88ms 
    1 1.2.3.4                              56  49 58ms 
    sent=2 received=2 packet-loss=0% min-rtt=58ms avg-rtt=73ms max-rtt=88ms 

> ip route add type=blackhole distance=201 routing-mark=main 

> ping 1.2.3.4                                         
  SEQ HOST                                     SIZE TTL TIME  STATUS           
    0                                                         no route to host 
    1                                                         no route to host 
    sent=2 received=0 packet-loss=100%

(“no route to host” means the packet is dropped before even reaching the output filter in http://wiki.mikrotik.com/wiki/Manual:Packet_Flow#Changes_in_RouterOS_v6)


Any ideas?