I have been attempting to make this work for the past two days.
I am running SuSE 10.1 with Shorewall and 3 NIC's.
eth0: 10.1.10.250 255.255.0.0 (Connects to Router)
eth1: 10.120.2.250 255.255.0.0 (Reserved for a future project)
eth2: 172.16.1.6 255.255.0.0 (Connected to LAN)
This machine is our LAN's internet gateway, among other things. Another server on our network is connected to the company's LAN, and is our department LAN's gateway to the company network. My route has been configured, as shown below.
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.115.0.0 172.16.xxx.xxx 255.255.0.0 UG 0 0 0 eth2
Unfortunately, none of the computers on our LAN are able to access the 10.115.0.0 network. This is what shows up in the firewall log:
Jul 20 01:21:56 automation kernel: Shorewall:FORWARD:REJECT:IN=eth2 OUT=eth2 SRC=172.16.x.x DST=10.xxx.x.xx LEN=106 TOS=0x00 PREC=0x00 TTL=127 ID=41313 PROTO=UDP SPT=1066 DPT=161 LEN=86
The routing work if I execute "shorewall clear", so I know I'm at the final hurdle. I've found information on how to Proxy ARP, but a lot of it isn't exactly clear to me or doesn't pertain to my situation. I could be wrong, though. I just need some help.