The server, or the firewall?

Here's the output of netstat -rn (note 1.2.3.4 is static IP assigned
by ISP, 1.2.3.1 is default gateway):

Routing tables
Internet:
Destination Gateway Flags Refs Use Mtu
Interface
default 1.2.3.1 UGS 8 139896 - sis0
1.2.3/24 link#1 UC 2 0 - sis0
1.2.3.1 0:5:5f:7b:f4:8c UHLc 1 0 - sis0
1.2.3.4 0:2:e3:5:60:66 UHLc 0 17 - lo0
127/8 127.0.0.1 UGRS 0 0 33224
lo0
127.0.0.1 127.0.0.1 UH 1 492 33224
lo0
192.168.0/24 link#2 UC 3 0 -
sis1
192.168.0.1 0:2:e3:16:92:a9 UHLc 0 2 -
lo0
192.168.0.3 0:3:47:40:a:e5 UHLc 0 13663 -
sis1
192.168.0.105 0:11:24:7d:32:3c UHLc 1 141 -
sis1
192.168.1/24 link#3 UC 2 0 -
sis2
192.168.1.1 0:2:e3:1f:5:a6 UHLc 0 97 -
lo0
192.168.1.2 0:10:4b:34:4a:aa UHLc 0 186 -
sis2
224/4 127.0.0.1 URS 0 0 33224
lo0

Does this help?

How do I add the route? I know "route add," but how would it work in
this case?