I am using 1:1 NAT on my network. For some reason I am unable to get Netmeeting to work.

Is there any way to solve this problem?

it should work, what's it doing?

The computers inside the LAN cannot receive calls. I can ping all the machines on the LAN using their external IP address and they reply. I have read some information about H.323, the protocol used for sound and video in NetMeeting and there are problems with masquerading.

Does Linux have a problem translating H.323 packets?

Is anyone else running NetMeeting though a Linux firewall with NAT?

I am using Redhat 7, is there a problem with this?


Please help!

Do all of your computers have valid Internet IP addresses?

You mention Masq so if you are masqing your machines then you only have one valid ip address which is the router.

It would not know which machine you are trying to call from the internet and would think you were calling it.

I think it should be possible to forward all traffic on certain ports to the windows machine, but I do not know how to do it off hand.


Ports for NetMeeting


Port Purpose
-------------------------------------
389 Internet Locator Server [Transmission Control Protocol (TCP)]
522 User Location Server (TCP)
1503 T.120 (TCP)
1720 H.323 call setup (TCP)
1731 Audio call control (TCP)
Dynamic H.323 call control (TCP)
Dynamic H.323 streaming [Realtime Transport Protocol (RTP) over User Datagram Protocol (UDP)]

Yes all the computers have valid Internet IP addresses?

No I am not using Masq. I am using NAT. The following commands:

ip rule add from 192.168.10.16 nat 213.23.151.1 table main
ip route add nat 213.23.151.1 via 192.168.10.16 table local

Should NetMeeting work?

I have tried running Netmeeting through NAT with no luck.

Actually I have tried running it in VMWare, bu that uses NAT to get the VM out to the real world and it bombs.

You list 192.168.x.x below and in the same paragraph say that computers all have valid internet IP addy's. That dog don't hunt.

IPmasq is simply a Linux version of Network Address Translation. So it uses the same technology as any NAT program.

Do all of your other web applications work? Browsing? IRC? etc etc?

Any other firewall rules in place?

I could be miss-understand here but thought that the following commands give my computer on the LAN a valied IP address:

ip rule add from 192.168.10.16 nat 213.23.151.1 table main
ip route add nat 213.23.151.1 via 192.168.10.16 table local

I have those two lines for each computer on the LAN but I change the addresses. e.g.

192.168.10.14 map to 213.23.151.2

These comands are working and to test the NAT I go to this web site, www.whatismyipaddress.com, and see if the addess is correct.

I have no other rules or ipchains at the moment.

I can browser the net, ftp, telnet and all the other stuff but just cann't get NetMeeting to work.

Please Help.

If all of those other services work.. I would have to guess that you are basically configured correctly. The question now is whether or not Netmeeting will work without a direct IP connection end-to-end.

I did a little research and here is some of what I found:

Netmeeting and firewalls causes problems for lots of people.
Netmeeting uses the H.323 protocol - which for some reason has embedded IP address information. The common symptoms that will be experienced if you are using these products:

* no incoming NetMeeting calls (for MSN Messenger this means that you cannot use the invite function)
* outgoing calls will allow audio/video transmission but no audio/video will be received.

In your particular case, with a Linux box acting as gateway.. it appears some folks have success with IPMasq, provided you update it to include a module called IP_MASQ_H323
This page might have the info you need to get this working:
http://www.coritel.it/coritel/ip/sof.../nat2/nat2.htm

There is some additional info about this problem in the Netmeeting Resource Kit:
http://www.microsoft.com/windows/Net...r4/default.asp

Good luck,

Kevin

I have a related site to contribute, just as a thought.

http://www.tsmservices.com/masq/