Can only connect at 10Mbps on my 10/100 network

All devices on my network support 10/100, yet I can only get 10Mbps on each computer. I've looked through the documentation for my router to see if there is any setting I need to enable and I can't find anything. The router is a Linksys WRT54GC and the computers are all running XP Pro with SP2. Thanks for any help.

 

Hi kosmicken
In the "speed" category, the Linksys WRT54GC could be measured in several different ways.
Via cables : WAN <-> LAN, LAN <-> LAN
Via antenna: WAN <-> LAN, LAN <-> LAN
Also, the 100Mb connection is an "ideal". Expect your WAN to LAN throughput to be half of that on Cat5 cable. The LAN to LAN speeds on consumer router/switches are rarely even mentioned. You'll have to measure those for yourself.
If you are using the wireless connection then expect the ideal WAN to LAN speed to be 25Mb at 5 feet. As you move further away, expect drastic reductions. In my house, two rooms away( 25 feet ) it's only 3Mb. To get 8Mb I have to set the computer up on the other side of the room.

 

OK, I'm not really too sure what you're reffering to, but to clarify, I'm talking about wired ethernet connections. The speed that shows up when you first plug in a cable and the little bubble pops up above the system tray that says Local Area Connection Now Connected. That should be 100 and it's only 10. Also if you hover over the connection icon in the system tray, the name and speed of that connection will pop up, like in the attached image. (That picture was taken with my other router that does connect at 100.)

 

You sure you are using Cat5 cable?

Because cat3 cable would do that to you.

Edit: just noticed you said you had another router that was fine.

 

so what are all devices connected to? switch? hub?

 

Hi kosmicken
Since you are 100% wired ( on your wireless router ) there are a couple of things you might check. First, open the "Local Area Connection" property sheet on each of your 10Mbps machines and examine what's listed for your connection.
Control Panel -> Network and Dial-up Connections -> Local Area Connection

Connection
Status: Connected
Duration: 07:16:06
Speed: 100.0 Mbps

If your speed shows 10.0 Mbps, then that is the negotiated speed that your hardware has decided. Since connecting a different router "allows" the 100Mbps speed, we may rule out a manually chosen speed. But just for fun, let's check the settings for your LAN card. With "Local Area Connection" still open, click the "Properties" button to bring up your LAN card (or cards). You'll be looking to select the correct card in the selection box, and underneath will be the network "stack" of clients services and protocols. Click on "Configure". The property sheet for your LAN card is now displayed. Select the "Advanced" tab. On the list of properties select "Link Speed & Duplex". The value is usually "Auto Detect" - hence the negotiated speed - however, this is a drop-down list table where you may manually choose your connection speed.

Value:
1000Mbps/Full Duplex
100Mbps/Full Duplex
100Mbps/Half Duplex
10Mbps/Full Duplex
10Mbps/Half Duplex
Auto Detect

Choose 100Mbps/Full Duplex, try it out and report back. You may have a faulty router

 

I finally called Linksys, and the solution that worked was to change the MTU from Auto to Manual and set it for 1300. Why does that affect the connection speed?

 

Hi kosmicken
They have provided you with a work-around. If the MTU ( default:1500 for ethernet) is reduced then the host computer or the router will advertise a lower MSS( maximum segment size). If you told the Linksys Tech that you are using "filter rules" to "stealth" your connection, then reducing the MTU will help. Normally, your router and a host computer will negotiate a transmission packet size via ICMP:Flags. The ICMP protocol, of which "ping" is a part, is sometimes disabled or blocked by "firewall filter rules" and so the router and the host just make a "guess" if packets are lost or fragmented. If the "guessing" results in too many unrecoverable packets, the result might be to drop the transmission rate and/or reduce the packet size. Some routers allow ICMP:can't fragment messages through anyways, even if ICMP has been blocked. Some, may also use a heuristic algorithm in an attempt to understand the nature of the packet loss and come up with a suitable response. Commercial routers give the administrator more flexibility in the ICMP blocking category. For instance a separate rule can be implemented to allow ICMP:can't fragment-type 3,code 4 messages and yet block other ICMP codes for security reasons.