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Old 11-23-2009, 05:16 PM
Eero Volotinen
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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
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Old 11-23-2009, 05:20 PM
Les Mikesell
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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.

--
Les Mikesell
lesmikesell@gmail.com
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Old 11-23-2009, 05:59 PM
Gilbert Sebenste
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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 **
************************************************** *****************************
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Old 11-23-2009, 06:16 PM
Les Mikesell
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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.

--
Les Mikesell
lesmikesell@gmail.com

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Old 11-23-2009, 06:18 PM
Eero Volotinen
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

>> 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?

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Old 11-23-2009, 06:18 PM
Gilbert Sebenste
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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!) ******
************************************************** *****************************
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 11-23-2009, 06:19 PM
Gilbert Sebenste
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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 **
************************************************** *****************************
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 11-23-2009, 06:21 PM
Gilbert Sebenste
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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 **
************************************************** *****************************
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 11-23-2009, 06:38 PM
"nate"
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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


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Old 11-23-2009, 07:02 PM
Gilbert Sebenste
 
Default 3Com 3c940 moel only giving me 100 mb throughput to network switch

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!) ******
************************************************** *****************************
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 

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