Why can't I connect with Netmeeting?

[blurredvision]

We had a major snafu today at work, and my being the resident IT guy, I get to fix it. This means that our small shop doesn't have a proper IT dept, but being the one who knows most about computers, I'm volunteered to do the dirty work. Our point-of-sale (POS) server computer went down, corrupt hard drive and all. A couple of hours of work couldn't save it, so I used good ol' GetDataBack to retrieve the current database for our POS system.

The POS software we use is heavily controlled by the company that makes it, and they lock down their software so tight that you have to pay them for tech support for the most asinine things, even installing the damn thing. Even rebuilding the database requires being "paid up" and under support, because everything is password protected.

This company connects through Netmeeting to do their dirty work, which in the past has never been a problem. Our network consists of a workgroup of about 11 computers, 2 hubs, and a WRT54G to disperse internet and gain access to wireless. We have a cable connection. Today, after I rebuilt the computer (XP Pro), I called this company to have them install the program for us. I absolutely could not connect to them through Netmeeting on two different IP's. On the same exact networking setup, this worked fine 3 weeks ago. The only thing that changed is the reinstallation of XP Professional on this computer.

Keep in mind that during all of this, I had an uninterrupted internet connection, and could access pages perfectly fine.

I tried connecting to this company on 3 more PC's throughout the office, to no avail. However, 2 PC's in the office would connect to each other internally just fine. The first thing I tried was turning off Windows firewall (even though Netmeeting is set with full exceptions), no dice. I then opened up all ports on the router that Microsoft says Netmeeting uses, nothing. I then set the server PC as a DMZ on the router, nothing. All the while, I could ping these two IP's that Netmeeting would not connect to. The company insists everything is fine on their end, waiting for a call, and I believe them.

A guy at work went home, plugged his PC directly into his cable connection, disabled his firewall, and I was unable to connect to him either. I could ping him fine, though.

I double-checked the router, and absolutely no access restrictions were set up.

Tomorrow morning, I'm going to try going straight from the cable modem to the computer, but that requires a bit of a long cord, which we'll hopefully have tomorrow.

Does anyone have any advice on what the problem could be? I'm stumped. The bad thing is that we need to get this up and running pronto, because we're dead in the water till we do.

 

[spidey07]

NAT will break netmeeting unless your internet router/firewall is configued to let it work properly.

That's probably what is going on, strange that it worked earlier. But you never know, that's the first thing to look at.

what model of router/firewall?

 

[blurredvision]

Originally posted by: spidey07
NAT will break netmeeting unless your internet router/firewall is configued to let it work properly.

That's probably what is going on, strange that it worked earlier. But you never know, that's the first thing to look at.

what model of router/firewall?

Doesn't completely disabling Windows firewall and setting up DMZ for the specific computer completely negate any firewalls? That's what has me confused. I've double checked the internal IP's and made sure DMZ was set up for the specific computer, and double checked windows firewall, and everything checks out.

 

[spidey07]

No. forwarding ports and DMZ do not fix the problem with netmeeting (H.323) and other protocols that negotiate port numbers in layer 7.

So you may actually have a NAT problem. If you want to fix setup a one-to-one nat from one of your outside IP addresses to an internal address. Do this at layer3, not layer4. So basically one outside IP address uniquely maps to an internal address. This will get NAT problems out of the way.

 

[blurredvision]

Originally posted by: spidey07
No. forwarding ports and DMZ do not fix the problem with netmeeting (H.323) and other protocols that negotiate port numbers in layer 7.

So you may actually have a NAT problem. If you want to fix setup a one-to-one nat from one of your outside IP addresses to an internal address. Do this at layer3, not layer4. So basically one outside IP address uniquely maps to an internal address. This will get NAT problems out of the way.

Is it sad that I understand your terminology, but I'm not readily able to do what you're requested I try? I've never setup a one-to-one NAT, and am unsure on how to accomplish this with my WRT54G. Also, when setting this up, am I to assume this will break the internet for all other computers on the network in the interim?

Thanks spidey, you've been a huge help, and it's not even fixed yet.

 

[spidey07]

I'm not too familiar with the SOHO gear. The linksys should automatically handle the H.323 protcol properly if the connection is initiated from the inside. Don't know though...a call to their tech support wouldn't be a bad idea.

If you only have a single outside IP address then it may very well break internet access. But you're in a bind.

Go to linksys support site and look up H.323 for your model. My gut tells me it shouldn't have a problem with it, but it is a known issue. FTP, SQLnet are also guilty of not liking NAT. Some protocols negotiate port numbers or even have the server make a connection to the client at the application layer, but modern firewalls know how to handle this. You just have to tell them to allow it (NOT the port, but the application)

 

[blurredvision]

Originally posted by: spidey07
I'm not too familiar with the SOHO gear. The linksys should automatically handle the H.323 protcol properly if the connection is initiated from the inside. Don't know though...a call to their tech support wouldn't be a bad idea.

If you only have a single outside IP address then it may very well break internet access. But you're in a bind.

Go to linksys support site and look up H.323 for your model. My gut tells me it shouldn't have a problem with it, but it is a known issue. FTP, SQLnet are also guilty of not liking NAT. Some protocols negotiate port numbers or even have the server make a connection to the client at the application layer, but modern firewalls know how to handle this. You just have to tell them to allow it (NOT the port, but the application)

I'm not too concerned with breaking internet access, as it will only take approximately 20 minutes to install the program. Email will be down during that time, but in my business, it's not at all critical. It could be down for a couple of hours without the slightest hit in productivity.

It's looking like since that will be the case no matter what, I'll just plug directly into the cable modem itself and go about it that way. It'll mean no internet and a long-ass cable stretched across the floor, but we have to get it done. Before tomorrow comes, though, I'll research what info you've given me, and learn a bit on my own.

Thanks a ton spidey, if you ever need anything, don't be afraid to PM.

 

[spidey07]

you can tell me where to buy cheap lightbulbs.

I'm tired of spending 6-8 bucks a pop in a house that has probably 75 flood lights.

http://forums.anandtech.com/messageview...atid=38&threadid=1955726&enterthread=y

But for sure you connecting directly the Internet would elminate any NAT problems on your end. Just keep in mind that SOME providers NAT you anyway if it is a consumer service.