Hello all,
As the subject states, I have a 3Com 3c940 Ethernet card to a 1 gb network switch. The switch detects it, but it only shows that it is giving me 100 mb/sec throughput. That card is rated for 1 GB...is there a way to force it to try to use 1 GB/sec? System-config-network isn't helping me here.
Thanks for any help!
******************************************************************************* Gilbert Sebenste ******** (My opinions only!) ****** *******************************************************************************
Gilbert Sebenste wrote:
Hello all,
As the subject states, I have a 3Com 3c940 Ethernet card to a 1 gb network switch. The switch detects it, but it only shows that it is giving me 100 mb/sec throughput. That card is rated for 1 GB...is there a way to force it to try to use 1 GB/sec? System-config-network isn't helping me here.
Check using ethtool that it is really connected with 1GB. Anyway, lot of stuff like harddisk affects speed of line.
You need enought fast harddisks (possibly with raid) to saturate full 1GB line .. on both ends..
-- Eero
Gilbert Sebenste wrote:
Hello all,
As the subject states, I have a 3Com 3c940 Ethernet card to a 1 gb network switch. The switch detects it, but it only shows that it is giving me 100 mb/sec throughput. That card is rated for 1 GB...is there a way to force it to try to use 1 GB/sec? System-config-network isn't helping me here.
Does ethtool say it is running at 1Gb? What is the source of the data? Many things can't generate much more than 100Mb, especially going too or from a disk.
On Mon, 23 Nov 2009, Les Mikesell wrote:
Gilbert Sebenste wrote:
Hello all,
As the subject states, I have a 3Com 3c940 Ethernet card to a 1 gb network switch. The switch detects it, but it only shows that it is giving me 100 mb/sec throughput. That card is rated for 1 GB...is there a way to force it to try to use 1 GB/sec? System-config-network isn't helping me here.
Does ethtool say it is running at 1Gb? What is the source of the data? Many things can't generate much more than 100Mb, especially going too or from a disk.
Nope, it says at 100 mb. I wonder why? Yep, I know I can only probably go somewhat faster, but it would be nice. Here's ethtool's output before I did something below...
ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: Twisted Pair PHYAD: 0 Transceiver: internal Auto-negotiation: on Supports Wake-on: g Wake-on: d Current message level: 0x00000037 (55) Link detected: yes
But then I tried this. Typing:
ethtool --change eth0 speed 1000 duplex full autoneg on
DID work! But I wonder why it didn't pick up on that automagically.
ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Advertised auto-negotiation: Yes Speed: 1000Mb/s Duplex: Full Port: Twisted Pair PHYAD: 0 Transceiver: internal Auto-negotiation: on Supports Wake-on: g Wake-on: d Current message level: 0x00000037 (55) Link detected: yes
And thanks, Les, for the ethtool reminder/tip!
******************************************************************************* Gilbert Sebenste ******** (My opinions only!) ****** Staff Meteorologist, Northern Illinois University **** E-mail: sebenste@weather.admin.niu.edu *** web: http://weather.admin.niu.edu ** *******************************************************************************
Gilbert Sebenste wrote:
As the subject states, I have a 3Com 3c940 Ethernet card to a 1 gb network switch. The switch detects it, but it only shows that it is giving me 100 mb/sec throughput. That card is rated for 1 GB...is there a way to force it to try to use 1 GB/sec? System-config-network isn't helping me here.
Does ethtool say it is running at 1Gb? What is the source of the data? Many things can't generate much more than 100Mb, especially going too or from a disk.
Nope, it says at 100 mb. I wonder why? Yep, I know I can only probably go somewhat faster, but it would be nice. Here's ethtool's output before I did something below...
ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Advertised auto-negotiation: Yes Speed: 100Mb/s
I'd expect that to mean that it was connected to a 100Mb switch port or a managed switch configured to force 100Mb.
But then I tried this. Typing:
ethtool --change eth0 speed 1000 duplex full autoneg on
DID work! But I wonder why it didn't pick up on that automagically.
But then that wouldn't have worked either.
And thanks, Les, for the ethtool reminder/tip!
Mii-tool does some of the same things but won't show/force 1000BaseT. Also, you can put ETHTOOL_OPTS=... in your ifcfg-eth? files if you need to force something odd.
ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Advertised auto-negotiation: Yes Speed: 100Mb/s
I'd expect that to mean that it was connected to a 100Mb switch port or a managed switch configured to force 100Mb.
But then I tried this. Typing:
ethtool --change eth0 speed 1000 duplex full autoneg on
DID work! But I wonder why it didn't pick up on that automagically.
But then that wouldn't have worked either.
And thanks, Les, for the ethtool reminder/tip!
Mii-tool does some of the same things but won't show/force 1000BaseT. Also, you can put ETHTOOL_OPTS=... in your ifcfg-eth? files if you need to force something odd.
Are you using cat 5e or cat 6 (gigabit certified) cable?
-- Eero
On Mon, 23 Nov 2009, Eero Volotinen wrote:
Are you using cat 5e or cat 6 (gigabit certified) cable?
Yes.
******************************************************************************* Gilbert Sebenste ******** (My opinions only!) ****** Staff Meteorologist, Northern Illinois University **** E-mail: sebenste@weather.admin.niu.edu *** web: http://weather.admin.niu.edu ** *******************************************************************************
On Mon, 23 Nov 2009, Les Mikesell wrote:
I'd expect that to mean that it was connected to a 100Mb switch port or a managed switch configured to force 100Mb.
Managed switch, yes.
But then I tried this. Typing:
ethtool --change eth0 speed 1000 duplex full autoneg on
DID work! But I wonder why it didn't pick up on that automagically.
But then that wouldn't have worked either.
Hmmm. Why not? It did on my other servers.
Mii-tool does some of the same things but won't show/force 1000BaseT. Also, you can put ETHTOOL_OPTS=... in your ifcfg-eth? files if you need to force something odd.
Great! Thanks for the tips. Take care.
******************************************************************************* Gilbert Sebenste ******** (My opinions only!) ****** *******************************************************************************
On Mon, 23 Nov 2009, Gilbert Sebenste wrote:
On Mon, 23 Nov 2009, Les Mikesell wrote:
I'd expect that to mean that it was connected to a 100Mb switch port or a managed switch configured to force 100Mb.
Managed switch, yes.
D'oh! make that unmanaged switch, sorry.
******************************************************************************* Gilbert Sebenste ******** (My opinions only!) ****** Staff Meteorologist, Northern Illinois University **** E-mail: sebenste@weather.admin.niu.edu *** web: http://weather.admin.niu.edu ** *******************************************************************************
Gilbert Sebenste wrote:
Hello all,
As the subject states, I have a 3Com 3c940 Ethernet card to a 1 gb network switch. The switch detects it, but it only shows that it is giving me 100 mb/sec throughput. That card is rated for 1 GB...is there a way to force it to try to use 1 GB/sec? System-config-network isn't helping me here.
What kind of switch? many/most? NICs will often set the speed to 100 or 10Mbps if they can't auto negotiate the connection
Check the switch config to make sure that it's not trying to force the connection to some lower speed.
nate
On Mon, 23 Nov 2009, nate wrote:
What kind of switch? many/most? NICs will often set the speed to 100 or 10Mbps if they can't auto negotiate the connection
Check the switch config to make sure that it's not trying to force the connection to some lower speed.
I checked; it's not. All seems well. If it isn't, I'll back off and go back to 100 megs.
******************************************************************************* Gilbert Sebenste ******** (My opinions only!) ****** *******************************************************************************
-
Eero Volotinen -
Gilbert Sebenste -
Les Mikesell -
nate