Wireless LAN-to-LAN Bridge: connectivity issues with some PCs

Posted on 2004-08-24
Last Modified: 2010-04-11
Hi, I have a wireless LAN-to-LAN bridge using two D-LINK DWL-2000AP access points set up in bridge mode with directional antennas facing each other about 100 ft away from each other. Configured speed is auto which auto-negotiates to 54Mbps.

Site 1 has an Internet Gateway,  and a VoIP PBX system. Site 2 just has another Internet Gateway (different ISP). Both sites are operating on the same subnet ( Here's the config:

Site1: (~30 PCs + ~30 IP Phones + 3 IP cameras)
Gateway ISP1:
Wireless Bridge:

Site2: (8 PCs + 8 IP Phones + 2 IP cameras)
Gateway ISP2:
Wireless Bridge:

On Site2, two PCs are using ISP2 (manually configured), the others are using the default configuration from the DHCP server on Site1 using ISP1 as their default gateway.

This setup has been running now for about 8 months without trouble. However, now we see ourselves in the need to provide the ISP2 connection to some users on Site1. No problem. Or so I thought. Some PCs on Site1 show no connectivity at all to Site2, others do. This problem is not limited to a certain OS or device type, it appears to be simply random, although static to the same devices.

Am I missing out on something fundamental, are there any tricks I should know of or try? What happens if within one or two months Site2 grows from 8 stations to 50+ (which is the plan)?

The next steps I've been thinking of is sniffing on the network, to see if I can make out where the communication gets lost. I've also been looking into separating the subnets from each other and employing a device such as a Cisco PIX at each side of the wireless bridge in order to route the packets instead of switching them!?

Any helpful comments are greatly appreciated.

Thanks in advance,

Question by:jaldinger
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Accepted Solution

JRaster earned 400 total points
ID: 11886863
Have you updated the firmware on your DLINK's?

Expert Comment

ID: 11887440
What do you plan to do with the PIX's? VPN tunnel?
Why not just use a cheap router instead of a PIX to route the packets if you don't want the VPN tunnel?

You say the devices that cannot connect from Site1 to Site2 are the same devices, can you manually assign IP/Gateway info? Are you sure those devices have all the protocols your network uses installed?


Author Comment

ID: 11893852
JRaster, I had updated the firmware a while ago. I have double-checked to make sure I have the latest version, and indeed I had not. I upgraded this morning and successfully communicated one of the PCs that wasn't communicating before with the other side. Will try the others throughout the day and let you know.

slapshot45, the PIX VPN tunnels would provide additional security for the signals crossing the road. Manually assigning addresses didn't help, I had tried that before. As for the protocols used, we're purely IPv4 on those LANs.

Thanks for your help,


Author Comment

ID: 11897100
JRaster, some solutions are so simple you just don't think about it. Upgrading the firmware to v2.06 completely fixed the problem (for now anyways).

Thanks and take care.


Expert Comment

ID: 11903549
I have had issues wierd like that and upgrading firmware fixes it.  

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