Clients not getting default gateway address from router

RouterOS Wireless Networking
1

Hi

We are experiencing a rather strange problem with our wireless setup at the moment. Our setup is as follows:

  1. A Cisco router, which hosts an incoming Internet line. It also is configured for DHCP.
  2. The Cisco router is connected to an HP switch, which hosts two backbone RB532 units. These two units have 5.4Ghz point-to-point links each to AP’s on top of a mountain (bridged).
  3. The two bridged AP (each with an additional daughterboard) transmit a 2.4Ghz signal on WDS.
  4. Client wireless units have static IP’s configured. The client PC’s get assigned DHCP IP’s from the Cisco router.

Up to recently, everything was working fine. However, some client PC’s stopped receiving the default gateway address. They receive a DHCP IP’s and the subnet, but not the default gateway. This obviously restricts Internet surfing. The problem is becoming more and more apparent. No changes have been made to the AP configurations at any stage.

I’ve rebooted the AP, but this has made no difference. I’ve tried ‘repairing’ the local network connection on one of the PC’s; also, I’ve tried releasing and renewing the IP on a client PC. However, this seems to only solve the problem temporarily.

Any thoughts as to what the problem could be?

2

what is the OS of the affected machines? is it the same, or there is no pattern (hidden indication to a vista issue).

3

OS is mostly XP.

However, it seems we might have located the culprit: One of the client units had been set to act as a DHCP server (Acconet units) - the DHCP conflicted with the IP range on the wireless network - hence the confusion.

Regardless, I’m still to confirm whether this is indeed the case.

4

Normis

I suspect it is indeed a rogue DHCP somewhere on the network. I think I’ve identified the IP range (192.168.0.0/24). Our client range is on 172.16.54.0/24.

What is the most effective way to block the IP range and rogue DHCP from the network without causing problems for current clients? Our clients also do network sharing.