Having Issue With Linksys Wrt54g

[stevevan]

Background Information:

 

Hardware:

-- Linksys WRT54G wireless router, firmware v3.03.1

-- Computer #1: Desktop, Win 2K o/s with software listed below, hardwired into router

-- Computer #2: Laptop, Win XP o/s with software listed below, using Linksys WPC54GS 802.11g wireless network card

 

Software:

-- Echolink (a program for Amateur Radio operators to use VoIP to connect to users and radio repeaters worldwide.)

-- Zone Alarm Pro

-- Norton Antivirus

 

Problem:

Echolink requires access to UDP ports 5198-5199 in order to communicate. Using computer #1, everything works perfect...no problems. Computer #2 cannot get the UDP ports to work. Other than operating system, the only difference is that computer #1 is hard wired to the router while computer #2 is wireless. Proper settings are entered into the router configuration table. O/s firewall is turned off on computer #2.

 

I have double (and triple) checked Zone Alarm settings and all are identical on both machines. I tested computer #2 wide open (all Zone Alarm and Norton functions disabled) with negative results. Other than this issue, the router functions perfectly.

 

Anyone have any ideas/suggestions? (Amateur radio operators HIGHLY encouraged to reply!)

[TCH-Bruce]

Steve, I've seen similar problems with communication software with more than one computer behind a NAT router.

 

Can you open two more ports 5200-5201 and configure Echolink to use them on the laptop? That's the way I had to do it with another software on two machines.

[stevevan]

It also uses TCP on 5200. There's a system-check program that they provide and according to that, TCP works just fine. So I'm not even sure if that would work. It just seemed a little strange that it would work ok on a hard wired system but not on a wireless, with the only difference being, other than the cable, is the operating system.

[TCH-Bruce]

Have you checked the Linksys site. Maybe they have a config option you can use in thier knowledge base. I know D-Link has suggested configs for different programs.

[stevevan]

At first glance, didn't see anything. Doing a more closer inspection now. (BTW...I did talk with one of their tech's. He suggested hardwiring the laptop up and trying it. Will do that tomorrow.)

[Head Guru]

WD8NTL checking in

 

Well...

 

Here is what I would do.

 

In your linksys there is something called port forwarding. You can forward ports 5198-5199 to each of the nat'd computers. That way the ports are wide open to each of the PC's.

 

I use the port forwarding on my Linksys router for my web server. It works well.

 

Bill

[stevevan]

Port forwarding is set up for computer #1 (the hard-wired one) and it works just fine. I set up port forwarding for computer #2 (the wireless card one) identical to computer #1 and it don't work. Yes, computer #2 has an IP address assigned and it is matched up with what's entered in port forwarding. I've tried computer #2 with both DHCP and static IP addresses. FWIW...in skimming through FAQ's on Linksys' website, I saw something dealing with VoIP and upgrading the firmware. So I downloaded and upgraded and nothing has changed. Too much for me tonight. I'll try again in the morning.

 

BTW Bill...I looked for your call on QRZ...not listed. Expired?

[Head Guru]

Nope my license is active till next year.

 

Bill

[stevevan]

Okay...after a good night's sleep I started again this a.m. Hardwired computer #2 (laptop running XP) to the router. Still will not allow UDP port 5198-5199 to pass. So apparently it's something in XP as this happens in both wired and wireless mode. In doing this, it clears the Linksys router of any issues. Any other helpful suggestions? (P.S. I'm off to the caverns of Micro$oft to see if there is any related articles on this. )

[Madmanmcp]

Is Windows firewall on?

[stevevan]

Nope...(see previous posts). I even disabled Zone Alarm and Norton and it wouldn't work. Bob...do you know of a pgm to log traffic (kinda like ethereal)? Maybe I can trace the problem that way.

[stevevan]

UPDATE: Thanks to input from TCH-David, it is now working as I need it to. For those who offered input, thank you. If anyone needs information on what happend, feel free to PM me.

 

Thanks to the TCH family!

[TweezerMan]

The router was indeed the problem.

 

It appeared to me that the there was two port forwarding rules for incoming UDP ports 5198-5199 - the first forwarded those ports to Steve's desktop, and the second forwarded those ports to Steve's laptop. You can only forward a port to one PC at a time - the router would forward a packet based on the first rule it encountered. Any other rules for port forwarding on that port are ignored because the packet is gone from the router (there's nothing to forward when a second rule is encountered for the same port).

 

The router should not have allowed this, but I wasn't sure if it did anyway. If it did, the router would always forward an incoming UDP packet on port 5198-5199 to Steve's desktop (the first port forwarding rule). I asked Steve if he really had two port forwarding rules in his router. He did, so I had him delete the port forwarding rule to his desktop, and now the laptop works just fine.

 

Bruce's suggestion of using other UDP ports would work and allow Steve to use his Echolink software on either PC, but Echolink does not allow using other ports. Steve will only be able to use Echolink on one PC at a time, and if he wants to use it on the other computer, he'll have to reconfigure the port forwarding in the router to the other computer before he can do so.

 

So much for the morning brain-teaser!

[TCH-Bruce]

Bruce's suggestion of using other UDP ports would work and allow Steve to use his Echolink software on either PC, but Echolink does not allow using other ports.  Steve will only be able to use Echolink on one PC at a time, and if he wants to use it on the other computer, he'll have to reconfigure the port forwarding in the router to the other computer before he can do so.

Someone should suggest to Echolink to allow more ports to be open. Wireless lans are an everyday thing now.

[TweezerMan]

Someone should suggest to Echolink to allow more ports to be open. Wireless lans are an everyday thing now. 

I'd go even farther and say that NAT networks are an everyday thing too. I would have the same problem Steve did trying to use Echolink on my PCs here at home - they're all on a wired NAT network.

[TCH-Bruce]

I'd go even farther and say that NAT networks are an everyday thing too.  I would have the same problem Steve did trying to use Echolink on my PCs here at home - they're all on a wired NAT network.

Very good point! I have a hardwired lan at work. Would be useful there too.