I am backing up some data from a Dell Vostro V13 laptop which is currently running xubuntu 10.04 (the reason for the backup is that I'm aiming to install 12.04).
The ethernet port is running at only 100Mb/s whereas it's supposed to be a gigabit capable port. Running ethtool shows:-
Settings for eth0: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Advertised pause frame use: No Advertised auto-negotiation: Yes Link partner advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Link partner advertised pause frame use: No Link partner advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: MII PHYAD: 0 Transceiver: internal Auto-negotiation: on Supports Wake-on: pumbg Wake-on: g Current message level: 0x00000033 (51) Link detected: yes
Running ethtool on my desktop machine connected to the *same* switch shows:-
Settings for eth0: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Advertised pause frame use: Symmetric Receive-only Advertised auto-negotiation: Yes Link partner advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Link partner advertised pause frame use: Symmetric Receive-only Link partner advertised auto-negotiation: Yes Speed: 1000Mb/s Duplex: Full Port: MII PHYAD: 0 Transceiver: internal Auto-negotiation: on Supports Wake-on: pumbg Wake-on: g Current message level: 0x00000033 (51) drv probe ifdown ifup Link detected: yes
So why are the two machines seeing different "Link partner" settings? I tried Googling for "Link partner" but couldn't find anywhere that actually tells me what they mean, it *sounds* like it's what the 'other end' is advertising but from what I see above maybe it isn't.
By the way I have tried changing the ethernet cable, no change at all.
Can anyone elucidate things?
Seems like your laptop isn't auto-negotiating with the switch correctly. You can manually force it 1000Mbps F/D; http://www.cyberciti.biz/faq/linux-change-the-speed-and-duplex-settings-of-a...
You laptop negotiates it's link speed with the switch, not the other computer (I got the impression you thought it was have a conversation about the link type/speed with the other computer, but unless it can send and receive data properly it can't talk to anyone, this is a carrier sense issues between laptop NIC and switchport).
On Tue, May 15, 2012 at 01:50:33PM +0100, James Bensley wrote:
Seems like your laptop isn't auto-negotiating with the switch correctly. You can manually force it 1000Mbps F/D; http://www.cyberciti.biz/faq/linux-change-the-speed-and-duplex-settings-of-a...
Yes, I tried to get ethtool to change the speed to 1000Mb/s but although no errors were reported the speed stayed obstinately at 100Mb/s.
You laptop negotiates it's link speed with the switch, not the other computer (I got the impression you thought it was have a conversation about the link type/speed with the other computer, but unless it can send and receive data properly it can't talk to anyone, this is a carrier sense issues between laptop NIC and switchport).
No, I reported both computers' ethtool output to show that another Linux box successfully negotiated 1000Mb/s with the switch.
On Tue, May 15, 2012 at 01:50:33PM +0100, James Bensley wrote:
Seems like your laptop isn't auto-negotiating with the switch correctly. You can manually force it 1000Mbps F/D; http://www.cyberciti.biz/faq/linux-change-the-speed-and-duplex-settings-of-a...
Stop right here. If you need to force the link speed something is broken. For starters you need to force it at both ends if you're going to do it at all, and GigE mandates autoneg works so if it's not there's something going wrong.
GigE needs all 4 pairs to be operational; have you tried a different cable to see if that makes a difference and/or checked to make sure it's firmly plugged in (I've seen a link fall back to 100Mb/s when the cable is loose at one end, but do GigE fine when firmly pushed in)?
J.
On 15 May 2012 18:35, Jonathan McDowell noodles@earth.li wrote:
On Tue, May 15, 2012 at 01:50:33PM +0100, James Bensley wrote:
Seems like your laptop isn't auto-negotiating with the switch correctly. You can manually force it 1000Mbps F/D; http://www.cyberciti.biz/faq/linux-change-the-speed-and-duplex-settings-of-a...
Stop right here. If you need to force the link speed something is broken. For starters you need to force it at both ends if you're going to do it at all, and GigE mandates autoneg works so if it's not there's something going wrong.
GigE needs all 4 pairs to be operational; have you tried a different cable to see if that makes a difference and/or checked to make sure it's firmly plugged in (I've seen a link fall back to 100Mb/s when the cable is loose at one end, but do GigE fine when firmly pushed in)?
I've had this when cables get kinked or mistreated in any way then crosstalk becomes an issue. Cat 6 is far more forgiving and should be used even for patch cables to guarantee the integrity of gigE.
Cheers, BJ
On 15/05/12 20:46, John Woodard wrote:
I've had this when cables get kinked or mistreated in any way then crosstalk becomes an issue. Cat 6 is far more forgiving and should be used even for patch cables to guarantee the integrity of gigE.
Chris are they hand made cables or purchased ones of at least CAT5e spec
The other thing I have had is problems with cheap consumer Gig-E switches where they can just be a bit funny about exactly what NIC's will reliably link at 1000Base-T
I had a netgear switch for a while that would randomly decide that a couple of my machines only deserved 100Base-T. Power cycling the switch or changing ports would often cure it for a bit but the real cure was to replace it.
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Chris Green -
James Bensley -
John Woodard -
Jonathan McDowell -
Wayne Stallwood