Multihome policy routing

[John Mok]

Hi,

I tried to setup a FTP server running on FreeBSD 4.11 as follows :-

     (DMZ subnet)
           61.1.1.1/27
---------------- Firewall ---------- Internet
|                    |10.144.1.1/24
|                    |(Intranet)
|                    |
|61.1.1.3/27 em1     | 10.144.1.254
FTP server -----------------router
       10.144.1.10/24 em0

The following routing and ipfw rules are added on the FTP server :-

#route add default 61.1.1.1
#ipfw add 101 fwd 10.144.1.254 ip from 10.144.1.10 to any
#ipfw add 201 fwd 61.1.1.1 ip from 61.1.1.3 to any

When I tried to connect from a host (e.g. 10.144.1.10) to the DMZ 
interface 61.1.1.3 of the FTP server via the gateway 10.144.1.1, it 
failed. However, I shut down the interface 10.144.1.10, then it 
succeeded. The routing was NOT symmetric.

My question is when FreeBSD can setup two routing tables and do 
something like Linux as follows :-

ip route add default nexthop via 61.1.1.1 dev em1 table T1
ip route add default nexthop via 10.144.1.254 dev em0 table T2

ip route add 0/0 dev em1 table T1
ip route add 0/0 dev em0 table T2

Thus, the symmetric routing is maintained, when a host (e.g. 
10.144.1.10) connects to 61.1.1.3 via 10.144.1.1.


Thanks a lot.

John Mok