# [SOLVED] Wifi router do not detect LAN cable with increased length



## hitesh7k (Dec 27, 2013)

I have WR720N TP link router. When I connect straight LAN cable of 1 meter from ISP modem to Routers WAN port, Wifi works perfectly. 

When I increase length of the cable to 20 meters, router does not detect the cable:blush:. When I connect same cable to PC, internet work fine.

Edited:
I simplified the question so that, I could explain it easily. :facepalm:I now think I shouldn't have done that. Let me explain it fully. :smile:

I have two wifi Routers. D-Link DIR-600L and TP Link WR720N. I connect D-Link to Modem. TP link is connected to D link with LAN cable. When I use SHorter length cable everything works fine. SO, no configuration issue, I think. 

When I use longer length cable TP link do not detect the cable:banghead:. If I connect that long cable to my PC directly it works fine with 2 mbps internet.

What I could conclude from long internet searching, is that ;

It might not detect because of Half or Full duplex configuration of LAN ports in different routers.

Connection:
Modem LAN >>> D Link WAN >>> D link LAN 1 >>> TP Link WAN >>> wireless
(WAN configuration may not be ideal, but in my defence:grin:, it works with short length)


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## Wand3r3r (Sep 17, 2010)

*Re: Wifi router do not detect LAN cable with increased length*

Welcome to TSF!

Is this long cable a store bought cable or home made?

A cable has no affect on wifi. You will always be able to connect to the routers wifi. The only question is if you get internet or not.

Since it appears you don't get internet with the long cable it is most likely a defective cable.

If you are using two routers in series as you are you should follow this setup
Connecting Additional Routers | Tech Support Forum

According to the WR720N TP link routers manual it only supports 10/100 on both the wan and lan ports. The same is true for the Dlink. They both support mdi/mdix and auto negotiation. 

Everything points to the long cable as being the problem


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## hitesh7k (Dec 27, 2013)

*Re: Wifi router do not detect LAN cable with increased length*

Thanks for reply

It wasn't Defective cable as it was working with PC. I found solution anyways... I used cross cable and every thing is working fine.

This also might be because first straight cable was not properly crimped. but Cross cable is working good for me.


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## Wand3r3r (Sep 17, 2010)

*Re: Wifi router do not detect LAN cable with increased length*

both routers are mdi/mdix enabled so whether straight or cross both will work. Looks like you finally got a good cable.


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