Model : TD-W9980

Hardware Version : v1

Firmware Version : 0.6.0 1.12 v0021.0 Build 150507 Rel.40130n

ISP : Sky Broadband

Hi forum.

I'm trying to make use of static routes on my TD-W9980 to route traffic between two private subnets and am having problems.

Here's a crude diagram of my setup:
[CODE] (Internet)
|
|
+-----o----+
| TD-W9980 |
+-----o----+
|.1
|
+-------+--------+----------+--------+ 192.168.128.0/24
| |
|.10 |.20
+-----o----+ +-----o----+
| FBSD g/w | | Web srvr |
+-----o----+ +----------+
|.1
|
+-------+--------+-------------------+ 192.168.255.0/24
|
|.2
+----o----+
| Client |
+---------+[/CODE]

I have configured a static route on the TP-Link router as follows:
- Destination IP Address: 192.168.255.0
- Subnet Mask: 255.255.255.0
- Gateway: 192.168.128.10
- Interface: LAN
- Status: Enabled


The TP-Link router is not properly routing packets destined for 192.168.255.0/24 back through the FreeBSD gateway. For example:

- Client tries to connect to the Web server
- Using tcpdump on the FreeBSD gateway, the SYN packet can be seen passing through and out of the interface onto the 192.168.128.x network.
- tcpdump on the Web server shows the incoming SYN packet and the outgoing SYN/ACK response sent back to 192.168.255.2. The web server has no specific route back to 192.168.255.0/24, so the packet is sent to the default gateway (the TD-W9980)
- The TD-W9980 should route the packet back to the FreeBSD gateway, but...
- The packet is never seen by the FreeBSD gateway

The tcpdumps indicate that the packets are going missing at the TD-W9980.

Anyone else seen a similar issue and figured out what was wrong?