Cisco AP541 Issues.... (DHCP, Multicast, etc...)

[MagnusLirell]

RegardsHello everyone,

I bought the AP541 since I thought I might just as well take the plunge and get a "real" AP rather than the Netgear 102's that I had in the past
( and been working perfectly fine I might add ).

First issue is DHCP - I just cant get an IP from my W2K3 server and or router... so I call Cisco and Cisco tells me to call my wendor and my wendor

tells me to call Cisco...

Eventually I find out that if you do a registry hack on W2K3 and disable the multcast/bradcast limit in the AP I actually get an IP.

Weeey - Happiness.... for a while...  but whenever I use my IP TV (which uses broadcast) I loose connectivety to the AP *bummer*

Oh well... I will soon get a Cisco Switch where I can manage the broadcasts so no biggie....

Well - turns out the IP TV wants the IP from my router/modem and not from my server which means I'm back to square one.

AP wont "pass through" DHCP requests and it will "die" on excessive multicasts/broadcasts.

Ironic how a $70 AP does just fine and a $500 Cisco AP makes you want to throw the thing out the window.

Thoughts / ideas ?

Regards,

//Magnus

[MagnusLirell]

... gateway issue resolved...

[lokibjensen]

I've been having the same issue for months.  Can you please let me know what you did to fix the problem?  Everything works fine after a reboot for a few days to a month and then all of a sudden the clients cannot receive DHCP.  It works fine on the LAN but from the AP's it just stops until they are rebooted.  We're using the latest firmware 1.9.2 and I've gone through this with support about 5 times and each time we think it's fixed the problem comes back.  Please please please tell me what you did to fix it.  Thanks!

[Stephan Veldhuis]

Hi,

I'm having the same kind of trouble here.

Is there a solution?

Most laptops work fine, but 2 (dell and hp) sometimes don't get an DHCP address.

Reboots helps most of the time, but it is very inconvenient.

Thanks.

[lokibjensen]

So far I have not found a resolution.  In fact, I had thought that my other sites were fine but just found out that

there is another site that has been experiencing issues for quite some time now.  I will know more tomorrow when I go but apparently it is only an issue with wireless.  Everything on the LAN works without issue but their wireless connection comes and goes.  I doubt it's exactly the same issue as I was having at the other site (DHCP dropping) because it comes and goes without the need for a reboot.  The other site would only fix itself when the devices were rebooted.

On a side note, it seems that so far (fingers crossed) the initial site that I had the issues with seems to be working fine.  We removed some Crestron TPMC-3X touchpanels that were hammering the system and that seems to have alleviated traffic which may have brought the AP's down.  Now this should not be the case and the AP's should not go down because of these remotes (cheaper AP's don't have this issue with these remotes) but it looks like so far things are good.  Cisco did give me the option of returning the AP's if the issue came up again.

I would recommend to everybody not to buy these AP541's until there is a verifiable solution to these problems.  In fact, I will never EVER buy one again.

[MagnusLirell]

Everything on the LAN works without issue but their wireless connection comes and goes.  I doubt it's exactly the same issue as I was having at the other site (DHCP dropping) because it comes and goes without the need for a reboot.

This is a very typical behaviour that mine has from multicasts/broadcasts.

The network is far from "overloaded" but whenever I turn on the IP-TV (~5-8Mbit / s) the AP just dies.

Well, all LED's are up and the unit seems fine, you can connect to it but you don't get any IP-adress handed to you
and units previously connected, with IP and fully working are just not able to reach anyting on the network and/or internet.

Turn off the IP-TV, wait a few minutes for it to stop broadcasting (on the network that is) and everything works like a charm.

Also, as you mention... the five times less expensive Netgear 102 AP does not have any of these issues.

Granted - it is not as sofisticated either, but sometimes I'd prefer units without "AI" ;)

//M

[MagnusLirell]

I don't have an answer to why some work and some doesn't and why it stops working over time as although the problem is the same, the root cause most likely isn't.

I have since upgraded to W2K8 (not because of this issue, replaced server) but the problem is still present.

Using the switch to filter out the broadcasts helps a lot - so if you have DHCP issues that's the first thing I'd  be looking at, are there excessive broadcasts / multicasts on your network ? Why the AP "locks down" because of it, even though the limiter is disabled is still a mystery to me.

I can not make the AP pass through the DHCP response from my router/gateway, it only works when I use DHCP on my server.
But if I do that, then my IP-TV doesn't work since it needs an IP from the gateway.

Catch 22

What I ended up doing was limit the ip-range on my gateway to only one IP and blocked the MAC off my IP-TV box in my Windows Server.

That worked fine until my ISP decided to remotely upgrade the firmware of the gateway and the "hidden / internal" settings where lost.
Not really an ideal solution / setup.... :D

Guess the easiest solution would be to sell the Cisco AP on ebay and use the old Netgear 102 again
but I'm too stubborn to give up so I'll have to find a solution that doesn't require the ISP gateway.
Well... either that or that Cisco either fix their FW or at least comment on WHY it's doing what it's doing and WHY that is considered correct and that everyone else is wrong.

//M

[Tarquin Joseph]

What firmware version are you running?  I recently installed one of these and upgraded to 2.0.0 firmware and I don't have the DHCP problem.  I don't have Multicast in the network so I can't comment on this issue.

However I do have a strange problem with a network printer that I use on the network though.  I can't print when I'm using the wireless network (enabled by the AP) but I can ping the printer from a wired device.

Also, pings to the printer don't work from wireless but they work from a wired connection. But I can access the web management console of the printer! Very strange.  It's almost as if the AP is filtering in some way. I have the WAP connected to an ESW500 switch and I suspect it may have something to do with the smart port setting on the ESW500 when the AP is connected.  I can't find a way to force the port settings to anything other than AP through CCA (ver. 3.0(1)).  I don't have the ping issue when the AP is connected through another switch but I still can't print to the printer when on wireless through the AP.  I didn't have this problem with a regular linksys AP/Router.  I'll have to do some more investigating to isolate whether the problem is the AP or the switch or both.

How is your AP connected to the rest of the network?  Are you also using a switch with Smartport configurations?

TJ

Message was edited by: Tarquin Joseph Update: I logged into my ESW500 switch and forced the port that the printer is plugged into as a printer role (this is not available from CCA).  I still could not ping the printer.  I then configured the port the AP is plugged into, as a switch port and not AP. Voila! I can ping the printer.  I had to remove and re-add the printer to be able to print though.  So the problem seems to be with the Smart port definitions for APs.  CCA now alerts me that I have an error in my configuration because the smartport definition is incorrect for the port the AP is connected to. If you have configured smartports on your switch for your AP, try forcing the switch role and see if that solves the problems you are having. TJ