Local Area Network drops from 100mbps to 10mbps in evening any ideas?

[AndrewShanklin]

Hi all,

Sorry for the long explanation but thought I would explain the setup....

I have setup a small windows network between my main Compaq tower PC (Windows XP), another Dell PC (Windows XP) , a Compaq Laptop (Windows XP), and a Mac running OS X 10.5.5

The main Compaq PC is connected to a Linksys WAG325N Modem Router 10/100 via Ethernet in port 1 and then in the other 3 ports is connected cat5 Ethernet cables running to the Compaq laptop, the Mac and the other Dell PC etc...

There are then 2 x Wireless Print Servers, 2  x Wireless Linksys Cameras, 1 x Skype Phone, Iphone's, Dell Laptop XP etc... connected wirelessly to the network.

During the Day everything works fine and speeds across the network are fine.

However, on occasions in the evening when all but the "Wireless" equipment is left on, we sometimes leave on the main Compaq tower PC and access it remotely via LogMeIn from home.

This has worked fine over the last couple of weeks but we have now found that If we leave the office at say 6:00pm and access the Compaq tower PC via LogMeIn at around 8:00pm (a good period of time later), the Local Area Network adapter icon in the taskbar is showing connected at 10mbps, where it has been at 100mbps all day when we have been using it.

If we restart the PC, it still reconnects at 10mbps and only when we restart the router or disconnect the local area network and then reconnect it goes back up to 100mbps and then it continues to be fine.

Dropping to 10mbps is obviously a problem because it means accessing the computer remotely is really slow.

After looking into this it seems that sometime during the PC not being use the PC has renegotiated the network speed with the router.

I have tried forcing the network adapter on the main Compaq tower to be 100Mbps/Full Duplex instead of auto negotiate, however this causes the network access from other pc's to the main Compaq tower to be slow and so I have had to put it back to auto negotiate.

So in short my question is....

What would cause a Pc on a network which is used constantly all day and is fine and when it is left for an hour or two in the evening  renegotiates the speed from 100mbps to 10mbps.?

The router is fine, the cables aren't damaged the network card works fine, in the evening their is even less running on the network than in the day (so it is not some form of overload).

I just can't figure it out.

Any ideas?

Thanks in advance.

Andy.

[sickpuppy]

Some bizarre power saving feature?

[Jeewhizz]

Maybe the cleaners are going in and downloading teh internet?!

[Rosco]

Maybe the cleaners are going in and downloading teh internet?!

I was thinking something along those lines, maybe somebody is scheduling downloads via bittorrent or something... but that wouldn't make NICs switch to a different setting.

It does sound strange.  Why not try leaving on the other wired computers and log into them and see if the same thing happens, it might be the switched ports on the router changing... maybe change around the cables to troubleshoot it further?  Maybe its LogMeIn thats conflicting with the card when the connection initiates.  Try installing a free VNC server as well... I use UltraVNC with either a VPN connection or port-forwarding on the router.

[AndrewShanklin]

Thanks Guys, it is a really odd situation.

Out of interest you don't think it could be some form of Vista to XP issue do you?

i.e. if you connect to the Compaq tower pc via Logmein from a vista machine it for some reason changes the transfer speed to 10mbps instead of 1000mbps?

Thanks

Andy.