Router Drops Downstream Speed to ~9mbps

[CrackaLackaZe]

I just signed up with a new ISP that has pre-wired ethernet in my building. When I connect the cat5 directly from my computer to the wall jack, I get speeds of around 50mbps down/50 mbps up.

However, when I connect my NetGear WNDR3400 in between, my downstream drops to ~9mbps, but upstream is unaffected. I have the NIC on my computer set to 100mbps full duplex, if I set this back to Auto Negotiation, I get the same gimped 9mbps speed that I would through the router.

I spoke with the ISP tech support and they said bad cabling in the building or my apartment might be interfering with the Auto Negotiation protocol between the them and my router, and this is causing it to drop down to 10mbps instead of 100mbps.

The problem is, I can't find any place to disable Auto Negotiation on my router, is this option available on any consumer routers? I really need a router for my home network but I don't want to lose all that bandwidth I'm paying for!

 

[owensdj]

Be very, very careful about setting a NIC to full duplex rather than letting it Auto Negotiate. The switch will fall back to half duplex on that port, and you'll get major problems with a duplex mismatch. I learned this the hard way.

It sounds like the ISP tech support is probably right. One way to get around the problem is to get a switch that allows you to manually set ports to 100Mbit full duplex. Plug the ISP's ethernet into that port, and plug your router's WAN port into one of the other Auto ports.

 

[spidey07]

The tech is dead wrong. Cabling doesn't affect autonegotiation as it isn't really a protocol, it's just capabilities sent in the link pulse.

So if I understand if you have your computer directly to the ethernet jack, and it's set to 100/full you get 50/50 speeds. If you set it to auto you get the gimped speeds? If that's the case then the switch port your are plugged into on their network is hard set to 100/full. When you use auto you get a duplex mismatch and the bad speeds. Tell the ISP to set your switchport to autonegotiate.

 

[JackMDS]

The feed that you get is probably already going through a Router somewhere in the building.

 

[her209]

Can you do this?

Disable DHCP server on the router. Connect the Ethernet from the wall to one of the LAN ports on the router. Connect the PC to one of the remaining LAN ports. Set your PC to auto-negotiate.

Disclaimer: The above may not work if the ISP disables trunking on their side of the switch.

 

[mosco]

Just out of curiosity, do you have QoS turned on on the router?

 

[CrackaLackaZe]

Thanks for the replies guys. I will get them back on the phone and try a couple of suggestions when I get home and let you know what happens. By the way, is disabling autoneg not possible on consumer routers?

 

[CrackaLackaZe]

Just out of curiosity, do you have QoS turned on on the router?

I turned it off and on but it didnt seem to make a difference in my case.

 

[CrackaLackaZe]

So I did some more prodding today and the ISP confirms that they have their switch port set to autoneg. They also tell me that I am connected directly to their switch port, with no middle tier router from their end.

Despite all this, and trying out a new TL-WR1043N router, I am still having the same issues. If I put a 10/100/1000 switch between the wall jack and my router, could I force the switch to receive 100mbps from the WAN and let the router's autoneg recognize the 100mbps correctly?

 

[ViviTheMage]

My DIR - 655 allows you to set AUTO NEG, or 10/100/1000, 10/100, or even 10.

I am surprised your router(s) are having these issues ... where are you getting these 50/50 speeds from exactly? Internet speedtests?