WNDR3700v2 not 100M/full duplex

[SoleX]

Hello,

I have a 100 mbit internet connection. My router only connects to it at 100M/half.
When the PC is plugged in directly and forced to 100mbit full duplex i have 12,5 mb/s speed, else it is crap.
The same crappy speed is now acquired with my new router (correctly configured with ISP ip-settings).

How do i force my WNDR3700v2 router to use 100M/full ??

Thanks in advance!

[Simon0]

100Mbps WAN is still not so common, is your WAN 12.5Mbps? eg. I have a fairly new gateway from the ISP and the connection rate between the router and the gateway is still 100Mbps, the gateway out to the Internet is 3Mbps (what I'm willing to pay for)... I can upgrade to 24-32Mbps, though.. but it's not worth the extra cost...

[SoleX]

Yes i have a 100 mbit WAN internet connection. Although I cannot use it at the fullest as the router auto negotiates @ 100M/half instead of 100M/full.

When I force the PC @ 100mbit full duplex and no router I obtain the maximum speeds.
When the router is inbetween the speed is only nearly 10 mbit.

What are my options?

[quagmire]

Does this summarize?

1) Modem (model?) connects to LAN at 100 Mbps/Full Duplex.

2) WNDR3700 auto-negotiates that connection as 100 Mbps/Half Duplex

3) Your PC also auto-negotiates as though connection were 100 Mbps/Half Duplex, but if you force the PC to Full Duplex, it runs at Full Duplex.

If the above is correct, then there is a problem with either the cable or the modem.

Can you try a different cable between the modem and the router? Does that help?

[SoleX]

1) Modem (model?) connects to LAN at 100 Mbps/Full Duplex.
Direct connection to switch in university campus, indeed 100 Mbps @ WAN port of router

2) WNDR3700 auto-negotiates that connection as 100 Mbps/Half Duplex
WAN port status: 100M/Half (I cannot force type of duplex so yes: auto negotiate)

3) Your PC also auto-negotiates as though connection were 100 Mbps/Half Duplex, but if you force the PC to Full Duplex, it runs at Full Duplex.
No, PC-WNDR3700v2 LAN (with 2 PC's) is a gigabyte full duplex network and runs perfectly.

If the above is correct, then there is a problem with either the cable or the modem.
The cables are OK. A friend of mine has the same connection (same building) with fast routing. With his equipment+laptop+cables @ my "wall-socket" he found the same speed issues as I did.

Can you try a different cable between the modem and the router? Does that help?
Been there done that

[Simon0]

Ah, I think I understand... Many universities still have a few legacy switches that were quite expensive at the time. They are relatively old and may not be compliant... Having to "force" duplex is not ideal. Are you able to contact the university IT staff and ask to have your port "switched" to a different port or even better to a different network switch. They should be in the same "rack", so it should be easy for them. Their racks usually have a mix of newer as well as older switches, so your probably on a legacy switch. Most switches made in the last decade are now Gigabit-type.. (most school still restrict the speed though).

Also, connect the WAN port of your router to your PC (as a test only) to see if it negotiates at Gigabit or 100Mbits (duplex or half-duplex) speeds... just to narrow down if it's a failing WAN port on the wndr3700.

[SoleX]

Hello Simon,

I have already tested the WAN port. It does switch to 100M/full when connected to another 100 Mbit device.

Your explanation seems to be similar with my situation. I will send an email to the IT with your suggestion.

Thanks in advance

[SoleX]

Hello,

I have contacted our IT "service" and they simply tell me to force duplex to 100 mbit. But the router does actually work perfect at my friends appartment @ 100M/Full auto negotiate.
They also told me the switch works as it should.

And so the problem still exists.

- Can resetting the switch solve the issue?
- Can I manually force duplex to 100M? With 3rd party firmware?

Thanks!

[Simon0]

Thoss lazy University IT staff... They really should change the port at least. If you can get full speed at your friend's room, but you are still experiencing slowdown even if forced, then you really should insist that they do more diagnostics.

Btw, how are the shape of the wires on the wall jack... corroded, bent, missing a wire, etc....

[SoleX]

Indeed, its really frustrating.

We have also checked the direct connection socket in the meter with my friends laptop directly connected: same issue. With his router: same issue.

- I'll check the sockets for bad wires.

- Can I use 3rd party firmware to force the router to use the 100M/Full protocol instead of 100M/Half?