LAN insanity

[Darren]

Hey Guys,
Here I have one hell of a problem which is driving me nuts.

A bit of background info, I was using Telstra Cable, standard Telstra modem through a Linksys Router which worked flawlessly for 2 years straight.

Last week I thought bah to Telstra's plans and needed the upload speed for JC so off to DSL I went, Internode activation all done, I order my modem and away we go.

My setup
Billion 7300G RA off to D-Link gigabit switch which then goes off to multiple PC's (1 Desktop Win7 Ultimate (LAN), 1 Server - WHS (LAN) + VMs (LAN + WLAN, 3 laptops - 2 Win7 Pro (WLAN) and 1 XP Pro (WLAN) around the house.

Wake up the following morning and couldn't browse any web sites from my main machine (ethernet into the gigabit switch), not even the modem interface despite the modem indicating it still had sync and connection to internode yet I could ping it and any external site, tried from another machine which exhibited the same problem, I jumped to a VM which happened to be on wireless and that worked perfectly fine.

I power cycled the modem, went to work, came home and it was mentioned the net wasn't working, exactly the same thing again so another power cycle and away it went for another round before having to do another power cycle.

So this is where I'm scratching my head, LAN appears to be fine, access shares, other machines without any problems when this occurs which seems to be every 5 - 6 hours.

I thought OK it must the modem so yesterday I went out and bought another modem, get up this morning and yep you guessed it no ethernet connection again but this time no wireless either and all indicating lights telling me everything appeared fine.

The only thing which has been added to the network has been TiVo which I have now unplugged from the network to see whether that's it although it has been on the network previously without any problems.

Other things I've tried whilst ethernet is down
Ping other machines on the network - AOK
ping google etc - AOK (makes no difference whether DNS is assigned manually / auto)
Disabled windows firewall / av (ms security essentials)
Use DHCP instead of static addresses
Upgraded firmware and even reflashed them (Billion 7300G RA & D-Link G604T)

The next couple of things I have in mind:
1- Plug straight into the gigabit switch rather than go through the modem / router.
2- Bridge the modem and run it through a linux box.
3- Bridge the modem and let the old Linksys router look after things.

With 2 and 3 I don't really want to do purely for the reason it should just plain work.

So there we have it, any idea's at all? Time for tea.

Thanks

Cheers
Darren

[PaRaDoX]

try this from a command prompt

"telnet www .google.com 80"

80 specifys the port which is http

telnet can be used to establish a connection on different TCP protocols to test connectivity (i do it all the time at work)
Have you checked your VC channel settings on the router? I know you can set it on the billions (i think that's what its called)

%99 of the time ICMP packets will be allowed through firewalls as a default, could it be firewall related?

Simplify the issue, disconnect all other devices except a test machine plugged straight into the billion with a staticly set Ip address. Is your public IP dynamic or static? From where do you run Address translation / do you run NAT at all?

Do you have any proxies set up? are you pinging Google or a ip address? does DNS resolve Google

next, punch this in

"tracert www.google.com" note the path it takes i've encountered many times carriers screwing something up with routing although usually it results in no connectivity.

If no luck, contact internode, internode don't actually own their own DLSAM's YET (will change soon) they just piggy back off everyone else's (usually TLS - Telstra, XYZ - Optus, IINET - iinet or AAPT - aapt)

this means their support may be slow because they have to put in a request to who ever owns the DSLAM and they have limited visibility

[Darren]

ping, tracert etc works perfectly fine.

Shortly after posting I started isolating the network and it came back to the windows server, disabled all port forwards on the router and all was happy.

So in short it's something to do with port forwarding, exactly why I am not sure and why only LAN would be impacted is beyond me but something to do with how WHS is setup I am guessing.

[PaRaDoX]

ping, tracert etc works perfectly fine.

Shortly after posting I started isolating the network and it came back to the windows server, disabled all port forwards on the router and all was happy.

So in short it's something to do with port forwarding, exactly why I am not sure and why only LAN would be impacted is beyond me but something to do with how WHS is setup I am guessing.

well in its nature port forwarding direct packets to a single address, if port 80 or any other http port was being directed else where that would cause this issue. Good to hear you found the problem