I put together a couple of mythtv boxes. The more powerful machine is an amdxp2400 and does video recording from cable. The other pc is a 1 ghz PIII. the amd box has a 10/100 ethernet card and homepna which i bridged. It is connected to a wireless router via rj45. It is serving dhcp and doing ip masquerading and dial on demand. The P3 machine has a homepna. I have mythtv running on the P3 machine for playback of videos stored on the amdxp2400 machine. the amd machine exports these videos via nfs. I noticed that whenever I use a laptop to access the internet (laptop is wirelessly connected) there is a slow down of the homepna connection between the P3 machine and the amd machine as demonstrated by choppy video and even causing the "server pc " to crash. If I turn off dial on demand , the playback on the P3 machine is smooth. If I dont have the P3 machine up and running, I can surf the net with the laptop (which is by the way a dhcp client) and the amd machine is stable. I thought it was an issue with shorewall, but when i removed it and installed a different firewall I reproduced the problem. I think its iptables not working well with the bridged interface but am not sure. Any ideas regarding what is happening? Any suggestions? Thanks

OK just to clarify, you set it up to connect the ethernet and (wireless?) networks, and it's bridged not routed?

Also I'm not up on the latest buzzwords I guess, whats a mythtv and a homepna and you said you have a wireless router that plugs in with rj45, did you mean the hub for the wireless LAN or something for whatever your internet pipe is? I'm guessing it's 100mb ethernet for the wired part of the lan, is that just the amd and the 2.4 on a crossover cable? you said dial on demand so it's dialup, like 56k and is it a software modem? internal? external? in the router or another box? what os/kernel?

Mythtv is a linux personal video recorder with network capability. Basically multiple machines can be configured as clients with one machine as a server. The server records videos, updates the database, exports the videos via nfs. The clients connect to the server database and locally mount the nfs exported directories, therefore, playback of videos accross the network. HomePNA is phoneline networking. BAsically, install a homepna card on each machine and plug each to a phone outlet. The phoneline wiring becomes one big network cable. No hub or router is needed. I am using a 10 mbps homepna flavor. I have three machines: AMDXP2400, P31Ghz, and a Laptop. the AMDXP2400 being the fastest is the mythtv server. It has both a 100/10 mbps ethernet card and a homepna card. It connects to a Netgear MR314 wireless router (dhcp server disabled) via the 10/100 mpbs card and then to the wall phone outlet via the homepna card. The P31Ghz only has a homepna card. The laptop has a Netgear MA401 wireless card. All machines have Redhat 8. The AMD Box is also an ip masquerading server providing internet connection to both the laptop and the P31ghz machine. It does so by bridging the ethernet 10/100 mbps card and the homepna card locally. Its bridge interface is designated br0 with an ip of 192.168.1.1 and is designated as the gateway to the internet. It is also a dhcp server. The AMDXP2400 firewall has the br0 interface as the local interface and ppp0 as the external interface. I have dial on demand on the AMD box via an external 28.8 modem which will be soon replaced by a 56k modem. Everything works fine except when I try to simultaneously surf the web on the laptop and play a video across the network using the P31ghz machine --> the playback on the P31ghz machine becomes extremely choppy, sometimes stopping and the AMDX
P2400 machine sometimes even crashes. If I kill the internet connection and just use the P31ghz machine to playback videos, the playback is smooth. Likewise there is no problem surfing the net with the laptop and no crash if the P31ghz machine is turned off. This leads me to believe that the problem is between ip masquerading and the bridge interface. If there is a simpler solution that will allow me the same functionality without having a bridge interface, I might try that. I dont know what you mean by routed vs bridged. Thanks for any help insight that you can give.