DNS issue with WAP4400N

Unanswered Question

The network setup is as follows.

(1)  WRT350N supplying DHCP and wireless on SSID, configured as 1.1, channel 6

(2) WAP4400N static IP 1.245 and 1.246 on same wireless SSID, channel 3 and 9

There is no wireless securtiy setup.. yeah, literally a big house in the middle of nowhere

The issue is with DNS and passing data through the wireless access points. Two of the laptops will no longer proccess dns requests properly, even though they have access to the rest of the network properly and the correct dns from the dhcp server; renewinig IP's and reconecting to the acces points do not help. Two of the other laptops will work fine during this time. Resetting the 4400AP's fix the issue for awhile, but then it happens again. Connecting to the wireless on the WRT350N there is no issues.

I want to upgrade the firmware on the 4400's but it isn't available yet. Still in QA. Are there any other fixes that might help?

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carnivaltribe Thu, 08/13/2009 - 12:13
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Hey Bro, I syphatise with you I have alos been experiencing this issue with a similiar model to what you have the wrvs4400n , every 3 days i have to reboot the router because both dns and file and print traffic gets booted, and after i reboot magically everything is normal , did firmware updates same issue , is anyone in linksys listening?????

Alejandro Gallego Thu, 08/13/2009 - 13:47
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A couple of questions for you:

1.are you running "N" only network

2.is your internet connection DSL or Cable

3.is the IP information complete on the WAPs

     such as IP, sub mask, Gateway and DNS

I will assume from your post that this is your set up:

Modem > WRT350N > WAP1 > WAP2 (all connected via ethernet)

If that is not correct, please let us know your network topology.

Right off it looks like you are trying to use the WAPs as repeaters and with consumer routers that may not work out. Also please correct me if I am wrong but the WRT350N does not support WDS so repeating its signal will not be possible. Please keep us posted.

Hi alegalle,

1. I'm running on standard channels (3,6,9) in mixed mode.

2. Cable, through local comcast provider

3. Gateway was not set per 4400 documentation that state it's not needed for static IP's on 4400. I set this anyway and problem still persisted.



WRT350N (6)

    |                |

Wap1(3)   Wap2(9)

all conected through ethernet (wired backbone) so not doing WDS or range extending, otherwise they would have to all be on the same channel but those routers don't support that of course.

Alejandro Gallego Fri, 08/14/2009 - 04:45
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On both WAPs make sure you specify GW (like you already have) and also DNS. You can point DNS back to your GW or use OpenDNS (My preferred) and

Once you connected to one of the WAP do the following:

On XP, click Start > Run > type cmd and click OK or hit Enter

From the command prompt type "ipconfig /all" with out quotes

make sure that the IP Adddress, Gate Way and DNS servers are what you have specified in your routers.

Now again from the command prompt

type ping (this should return a reply from

now type ping google.com (the first return should be a resolved IP address, then reply from the resolved IP)

Let us know if this is working out.

According to the documentation you don't even need to specify the default gateway on the linksys wap or the dns settings. These are obtained directly from the dhcp server on the WRT350N suppled by comcast. That would make no sense unless there is some internal bug that won't pass dns settings if this isn't set already, and "only" for G clients. I can try it but I doubt that will make any difference, like specifying the gateway. Also I did specifiy alternative dns on nslookup with the same results to rule out problems with comcast dns directly from the command prompt. During this time all N clients were working fine.

Also all G clients are Vista 32 bit, and the N clients are Vista/OSX.

I was waiting on the latest firmware release to see if that would clear up the issues.. as they seem related to "G" clients only which are Lenovo Windows 32 bit systems. As that has been delayed I wanted to see if there were any other suggestions to try that might clear this up, maybe a wide band radio channel that might be more compatible, or some other wireless setting I hadn't thought of.. or worse yet I didn't have the network configured properly using the right linksys hardware.

David Carr Tue, 08/18/2009 - 07:18
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Jason, what are the ip settings you are receiving from your router.  Are you receiving dns from the router?

Yes, the clients are receiving DNS correctly and can release and renew ip information fine. I can also use nslookup to select a different dns server and do manual lookups, which is where I tracked down the issue to. DNS lookups won't return consistantly, and usually not at all. Disabling wirelss and rebooting doesn't fix the issue, and the issue fixes immediately after rebooting the WAP. After a few days we are back in the same situation.

David Carr Tue, 08/18/2009 - 07:50
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Have you adjusted the wireless channel to see if that helps?  You could be getting wireless interference from something.  Is there any wireless other than yours in the vicinity?

Alejandro Gallego Tue, 08/18/2009 - 11:03
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I beleive we spoke a few days past, one thing that you may want to check is MTU size. I understand that the issue is on the WAPs and not the router as any client connected to the router performs as expected. Typically we adjust the MTU on DSL connections and not on cable which I beleive is what you have. Set the MTU to 1492 on the router and then also change the Advanced Wireless settings to force transmission for all G clients to 54Mbps. Let us know if that makes a difference.

The mtu size shouldn't affect the wireless connections, and in fact if I connect to the wap on the actual router I don't have any issues with those clients. It's just the WAP4400N's, but I can hard code the standard mtu size as you suggest on the broadband connection and set the access points to "G".

Any word on that new firmware for the wap's. I would like to test this out before deciding if I just need to replace them with something else.


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