Ethernet connection problem

[wsha]

I just installed Gargoyle on a TP-Link WDR3600, and I'm having trouble connecting to it over ethernet from an Asus Eee Box running Debian 8 with the MATE desktop (so using NetworkManager). I wanted to know if anyone had suggestions for debugging the problem. Here are a few things I have seen:

0. When I plug in the ethernet cable between the Eee Box and the WDR3600, nothing happens. The NetworkManager applet continues to say that ethernet is not connected.

1. The Eee Box also has a wireless card and can connect directly to the WDR3600 over wireless.

2. I can connect to the WDR3600 over ethernet from a laptop running Arch Linux and GNOME (so also NetworkManager).

3. I can connect to the internet from the Eee Box if I connect an old NETGEAR router to the WDR3600 via ethernet and then plug Eee Box into one of the LAN ports on the NETGEAR router.

So #1 and #3 seem to confirm that networking is working properly on the Eee Box, while #2 seems to confirm that ethernet is working properly on the WDR3600. However, when I put the two together directly, nothing happens.

[ispyisail]

do the Ethernet lights come on

[nworbnhoj]

0. When I plug in the ethernet cable between the Eee Box and the WDR3600, nothing happens. The NetworkManager applet continues to say that ethernet is not connected.

Bad cat5 cable

[wsha]

The ethernet lights do not come on when I plug the Eee Box directly into the WDR3600. I would guess a bad cable, but the internet connection works when I plug the Eee Box into the NETGEAR router and plug the NETGEAR router into the WDR3600. If I then leave either the Eee Box or WDR3600 cable connected from this working set up and move the other end of the cable from the NETGEAR router to the other component, the router's ethernet light does not come on and the computer shows no sign of registering the connection. I have tried several cables that otherwise seemed to work when used in other configurations.

[Lantis]

Do you have a crossover cable available?
That would be my hunch.

[wsha]

Not sure that I have a cross-over cable, but I will look into getting one.

I realized that one difference between the NETGEAR router and the new TP-Link router is that the TP-Link router's LAN ports are gigabit whereas the older router's ports are 10/100. I found these two threads about issues with gigabit ports that might be relevant:

http://ubuntuforums.org/showthread.php?t=2257060
http://ubuntuforums.org/showthread.php?t=2217661

Unfortunately, the monitor I was using just died, so I need to get another one before I can try the techniques in those threads.

[wsha]

Following the advice in those threads I linked to in my last post, I tried the ethernet connection speed with:

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sudo ethtool -s eth0 speed 100 duplex full autoneg off

and then the Eee Box connected to the WDR3600 successfully (NetworkManager connected automatically right after that command).

Then I tried the other command suggested in those threads to get gigabit speeds:

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sudo ethtool -s eth0 speed 1000 duplex full autoneg on

As soon as I do this, NetworkManager changes to showing that the ethernet is disconnected as though no wire were plugged in (same behavior as behavior forcing ethernet speed). Perhaps this is a configuration with the Eee Box and not with the router, but does anyone have any suggestions for something else to try?

It seems like both the Eee Box and the WDR3600 should be able to do 1 Gb/s. Here is the output of a couple diagnostic programs:

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$ lshw -C network
  *-network               
       description: Ethernet interface
       product: JMC250 PCI Express Gigabit Ethernet Controller
       vendor: JMicron Technology Corp.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: eth0
       version: 03
       serial: bc:ae:c5:69:97:64
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=off broadcast=yes driver=jme driverversion=1.0.8 duplex=full ip=192.168.1.116 latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
       resources: irq:46 memory:fbffc000-fbffffff ioport:ec00(size=128) ioport:e800(size=256)

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$ sudo ethtool eth0 
Settings for eth0:
	Supported ports: [ TP MII ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Half 1000baseT/Full 
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Advertised link modes:  Not reported
	Advertised pause frame use: No
	Advertised auto-negotiation: No
	Speed: 100Mb/s
	Duplex: Full
	Port: MII
	PHYAD: 1
	Transceiver: internal
	Auto-negotiation: off
	Supports Wake-on: pg
	Wake-on: g
	Current message level: 0x000020c6 (8390)
			       probe link rx_err tx_err hw
	Link detected: yes

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driver: jme
version: 1.0.8
firmware-version: 
bus-info: 0000:03:00.0
supports-statistics: no
supports-test: no
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no

[Lantis]

sounds like the ports arent auto negotiating with each other hence why you're able to make it work when you manually set everything.

This is also why i suggested using a crossover cable which is sometimes necessary in these situations where one device doesn't know how to negotiate the pair swapping. (i have a limited understanding though)

[wsha]

Thanks, Lantis. I was hoping that I would find a software solution, but I will look into getting a crossover cable to try out next.