atcomsystems.ca/forum Forums VOIP Phones & IP PBX Networking Gateway Routing Issue

This one is a head scratcher. Keep in mind that the facts stated below are based on what was relayed back to me over the phone while trying to resolve the issue. I haven’t physically laid my hands on the problem computer yet. I hope to have it in our office in the next day or so.

The client’s office is running a peer network. The router/WAP serves as the DHCP Server. It’s running private IPs on the inside.

The client purchased an IBM laptop, brought it to the office and connected to the wireless access point. He receives a valid IP, and he is configured for the correct gateway and DNS. He can ping any workstation on the LAN and they can ping him. He can also connect via HTML to the router/WAP. What he cannot do is get to the outside world via browser or ping. When trying to ping the outside world by IP Address he will receive a “Destination Host Unreachable” reply. Note that I said he is pinging by IP, so DNS isn't an issue at this point. I had him try unplugging a patch cable from a workstation that was getting out, and plug it into the laptop and then disable his wireless connection. He got the same error when using wired connection as he did with the wireless.

He left the office and took the laptop to his house where he tells me he encountered the same problem. I wasn’t on the phone with him at that point to know for sure what he did. In any event, I called the supplier who advanced him another laptop. It arrived today and he is having the same issue.

I’ve walked him through resetting the TCP stack to no avail. My supplier tells me he has sold over 500 of these with no issues, and I believe him. What is so bizarre is that the client claims to have had the same problem, with two different laptops in two different locations, yet right now there are working laptops in both locations.

No firewall software has been loaded and Windows Firewall is disabled. The issue happens rather in DHCP or Static mode.

For some reason, the packets aren’t being routed to the gateway.

Ideas?

What OS. I bet its vista. Have him check into the network settings. I dont know specifically where to look, but there is a setting that tells the "profile" how it should identify with the network connection. Lan only, Internet only, Lan and Internet. Not exactly like that but something close.

Vista? Not on any network my company has to maintain. It's Win XP Professional.

Have him try a traceroute and see if he is even hitting the gateway. Also see if he has two ip addresses setup with gateways. How about access rules setup in the routers?

Well it is possible to configure XP with this scenario through mmc and an ipsec policy. Essentially, allowing for web browsing strictly on the lan. However, an out of box system with a fresh install would not have this implemented.

Is this happening on both wireless and hard wire connections?

Jim, tracert fails as it never gets to the gateway. As far as router access rules, the router is a plain vanilla out of the box low end. Note though that what we're seeing here is "Destination Host Unreachable" not a timeout like you would see if you tried to ping a nonexisting LAN address. The laptop appears to not understand that the address is outside the local subnet and therefore must be sent to the gateway.

Nails, it is failing from both the wireless and wired NICs. The last time I saw this was on a desktop machine with a bad motherboard, but that just seems a bit unlikely here due to other considerations.

Well, i would open an mmc and check the ipsec snap-in at this point. Im thinking maybe some joker on the supply side thought he might be funny.

2 laptops, 2 networks, and the same problem....

Have him go to the command prompt and issue a "route print" to see what that says. I have seen cases where the routes get hosed and setting them manually with a "route add" takes care of this. Though I can't remember the circumstances I've seen this under. I think maybe the "route -f" will clear the routing table, though I'm not certain of this.

Also, could it be a problem with ARP cache on the router? Perhaps the router is confused as to which MAC address the IP number should be associated. Seems unlikely with two routers and laptops, though I suppose it could be a misbehaving wireless card driver.

Perhaps also have him check the event logs on that system. Maybe something would show up there to give you a better idea of what's happening.

All very good suggestions. I hope to have it at our office by tonigh so I can test the wired and wireless on our network.