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How to Change NIC speed without restarting the Linux AS 3 server?????

Last Modified: 2013-12-16
I would like to change the NIC settings from 100 to 1000, Auto_negotiation Yes without restarting the  Linux Machine. Please see the details below

# uname -r
# cat /etc/redhat-release
Red Hat Enterprise Linux AS release 3 (Taroon Update 6)
#ethtool eth0
Settings for eth0:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Half 1000baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  Not reported
        Advertised auto-negotiation: No
        Speed: 100Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: off
        Supports Wake-on: g
        Wake-on: d
        Link detected: yes
# cat /etc/modules.conf
alias eth0 bcm5700
options eth0 line_speed=100 auto_speed=0 full_duplex=1
alias eth1 bcm5700
options eth1 line_speed=100 auto_speed=0 full_duplex=1
alias scsi_hostadapter cciss
alias usb-controller usb-ohci
options bond0 miimon=100 mode=active-backup
alias bond0 bonding
Watch Question

Kerem ERSOYPresident


You can use ethtool command for modifying speed:
ethtool -s eth0 speed 100 duplex full autoneg on

The resuls are immediate you don't need to reboot. But for the next boot you can either remove:
options eth0 line_speed=100 auto_speed=0 full_duplex=1
options eth1 line_speed=100 auto_speed=0 full_duplex=1

Lines from your /etc/modules conf thiswill force your adapter to autonegotiation od change the "line_speed=100" to "line_speed=1000" if you want to do it manually.

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How would i set as Auto Auto for this server
Kerem ERSOYPresident

You want to set it back to auto ??

Then you'd issue:
ethtool -s eth0 autoneg on

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