Atheros Vs DLINK Router

sysengrnz

sysengrnz

New Member
After a bit of research myself on trying to resolve a wireless issue I've decided to leave this one to the floor for some "out side of the box" thinking.

Can anybody say "Wireless Meltdown"?? I can...

1. Clients with issues are all using Atheros wireless cards
2. Access Points are both DAP-2590's in Master/Slave setup to enable roaming.

Research say's that most Dlink routers utilize atheros chipsets, and the issues we seem to be having come from the Atheros cards within the laptops trying to pass data through the access point to the rest of the network.

Basic topology is as follows:

Client --> AP --> POE Switch --> Core Switch --> ISA --> Firewall --> Internet.

Not to be mistaken, ISA and firewall are separate.

ISA is being utilized for proxy authentication / auditing.

Clients via ethernet cable = working 100%

Client via wireless = Authenticates with the DAP-2590's - but browser does not recognize the authentication screen from ISA, no windows shares, nothing. Clients receive all DHCP information and correct. Gateway for the clients is the IP address of the AP they are connected to. We did have it set up as the ISA server seeing as the IP is on the same network, but that proved a bit problematic with a bit of a delay on getting the DHCP information.

From command line: Can ping all local IP address's, Can ping external IP's and name resolution is working fine.

*Sessions aren't establishing over wireless link is what comes to mind*.

Now I'm wondering: Why isn't the DLINK Router passing "session data" out to other clients on the network and in particular the ISA server utilizing the Atheros wireless cards on the problematic clients?

Is there something that I'm missing? an issue with the way data is traversing from the Atheros Card's to the Router? Is there a problem with how the Atheros Card's flag there data packets before sending them out and how the DLINK router's interpreting them?

It's weird how they were working fine with the AP's for about a week then all of a sudden, they're slowing dropping off, one at a time.

Needless to say, the Atheros card's are working fine with an older Dlink DIR-615.

If there is anybody here who can provide some additional guidance to this problem, please voice your opinion.


Cheers.
 
Consumer routers are cheap and perform pitifully, they cannot handle tons of TCP packets flooding them.

With all this grand set up you, how many clients are we talking about? Also, why the firewall and an ISA server? You might as well scrap those and just invest in a decent router as a decent router can do all of that and it is one box.
 
Re:

These routers are both commercial $400 US each, which can support up to 60 users on each. We've been doing a bit of auditing on the Routers and the CPU usage doesn't usually rise above 70%. We have set it up so that each router has its own separate DHCP pool to minimize the broadcast domain. Each router has no more than 40 clients on it at any one time. This was to provide additional load balancing to the network.

The reason for the setup is because the network requires the additional security due to the nature of the traffic being passed across it when ever our primary link fall's over. Basically corporate information utilizes this internet link in the event of catastrophic failure of the primary.

I wouldn't classify the current AP's as consumer routers. Not at that price.
 
well, not sure if I would consider D-Link an enterprise product, regardless. Cannot say that I have any experience with them either. Our APs at work are Cisco and are like $800 each, and they get push config from the Cisco Controllers.

However, that is not really helping your issue here, so...

If they get an IP via wireless but cannot browse, my first instinct would be to look at DNS. Make sure it is resolving forwards and reverse. Second I would look at your wireless encryption and make sure you are actually authenticating and hand shaking with the AP itself. There should be some sort of logging you can turn on.

From there you just need to troubleshoot it from process of elimination.

Good luck
 
Re:

We've confirmed that DNS is working as 90% of all users on the Wireless have flawless internet connectivity. It's only a few select users that cannot. I've proven that they can resolve DNS within command prompt, and ping all interfaces both internal and external. I've checked the logs and yes, those clients that are having internet access are completing the 4-way handshake. That is obvious by the fact that they are drawing the DHCP credentials. If it was failing, they would not be getting DHCP but merely an IPIPA Address.

I just don't see a logical explanation on why DNS would work perfect at the application layer through command prompt, but come to the web browser we're hitting issues. Replacing an atheros card with an intel 5300 card corrected the problem for one of the users involved, but I don't have a pool of 5300 cards that I can dish out to the rest. There has to be an explanation but I'm out of ideas. I've played with most of the settings on the AP's, but no joy.
 
I would start looking for driver updates, but that is just the first step. I would then next try any OS updates that are involved with network connectivity. Then I would make sure all clients are on the exact same OS version, ie one client doesn't have a hot fix that fixes the issue.

Like I said, take a working client and a non working and compare them and see what the differences are.
 
Re

I may have to do that, and it seem's to of started happening approx 4 - 5 days ago. Maybe a windows update that is cached on our ISA, finally made it's way out to those clients, and is causing them issues.

All AP's have current firmware, all cards have the latest wireless drivers also. I might try some older firmware for those wireless adapters and see if I make lee-way.
 
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