Solaris NIC speed and duplex settings

On solaris 10 dladm is the admin utility for Data-Link Interface which helps to display informarthe like Link Status (UP/DOWN), Speed, Duplex, MTU, VLAN Tagged and crucially statistics of network traffic.
# dladm show-dev
nxge0           link: down      speed: 0     Mbps       duplex: unknown
nxge1           link: down      speed: 0     Mbps       duplex: unknown
nxge2           link: up        speed: 1000  Mbps       duplex: full
nxge3           link: up        speed: 1000  Mbps       duplex: full


Setting NIC speed and duplex
Solaris is often unable to correctly auto-negotiate duplex settings with a link partner (e.g. switch), especially when the switch is set to 100Mbit full-duplex. You can force the NIC into 100Mbit full-duplex by disabling auto-negotiation and 100Mbit half-duplex capability.

Example with hme0:

1. Make the changes to the running system.
# ndd -set /dev/hme adv_100hdx_cap 0
# ndd -set /dev/hme adv_100fdx_cap 1
# ndd -set /dev/hme adv_autoneg_cap 0

2. Make kernel parameter changes to preserve the speed and duplex settings after a reboot.
# vi /etc/system
Add:
# set hme:hme_adv_autoneg_cap=0
# set hme:hme_adv_100hdx_cap=0
# set hme:hme_adv_100fdx_cap=1

Note: the /etc/system change affects all hme interfaces if multiple NICs are present (e.g. hme0, hme1).
The /etc/system settings listed above are not supported for configuring ce Ethernet adapters during system startup; you may either use ndd commands in an /etc/rc?.d script or create a/platform/sun4u/kernel/drv/ce.conf file with appropriate settings.

Example: /etc/init.d/nddconfig

#!/bin/sh

ndd -set /dev/ce instance 0
ndd -set /dev/ce adv_1000fdx_cap 0
ndd -set /dev/ce adv_1000hdx_cap 0
ndd -set /dev/ce adv_100fdx_cap 1
ndd -set /dev/ce adv_100hdx_cap 0
ndd -set /dev/ce adv_10fdx_cap 0
ndd -set /dev/ce adv_10hdx_cap 0
ndd -set /dev/ce adv_autoneg_cap 0

# ln -s /etc/init.d/nddconfig /etc/rc2.d/S31nddconfig

$ dmesg | grep ce0
Jan 20 11:05:01 crmmdb22 genunix: [ID 611667 kern.info] NOTICE: ce0: xcvr addr:0x01 - link up 100 Mbps half duplex
Jan 20 11:05:15 crmmdb22 genunix: [ID 408822 kern.info] NOTICE: ce0: no fault external to device; service available
Jan 20 11:05:15 crmmdb22 genunix: [ID 611667 kern.info] NOTICE: ce0: xcvr addr:0x01 - link up 100 Mbps full duplex

Manually determining NIC speed and duplex

If you have ce or bge interfaces, use kstat ce and kstat bge, respectively, to return NIC settings. All other interfaces may use ndd to determine NIC settings.

ndd example with hme0, assuming "instance" is 0:

# ndd -get /dev/hme link_mode
Interpretation:
0 -- half-duplex
1 -- full-duplex

# ndd -get /dev/hme link_speed
Interpretation:
0 -- 10 Mbit
1 -- 100 Mbit
1000 -- 1 Gbit

To query a different NIC, such as hme1, set the "instance" to 1, and then perform the link_mode and link_speed queries above.

# ndd -set /dev/hme instance 1

Note: the ndd commands above must be run as root. Otherwise, you will receive errors such as "couldn't push module 'hme0', No such device or address."

ce Ethernet adapters

Older versions of the Sun GigaSwift Ethernet 1.0 driver do not support the ndd link_mode and link_speed parameters. You may either install the latest Sun GigaSwift Ethernet adapter patch (111883) or you may use kstat ce ce_device to get speed and duplex information for ce Ethernet adapters.

For example  click here:

$ netstat -k ce | egrep 'link_speed|link_status|link_duplex'

Interpretation:
link_up - 0 down, 1 up
link_speed - speed in Mbit/s
link_duplex - 1 half duplex, 2 full duplex, 0 down

Host/link partner mismatch example

A large number of output errors or collisions may indicate a host and link partner mismatch. The following is netstat -in output from a system configured for 100 half-duplex while the switch was configured for 100 full-duplex.

Name  Mtu   Net/Dest     Address      Ipkts      Ierrs Opkts       Oerrs     Collis    Queue
ce0   1500  192.168.1.0  192.168.1.1  2707133478 25    2895422910  142310052 182856975 0
In this example, the switch was configured for 100 half-duplex and the system was configured for 100 full-duplex. Note the percentage of Ierrs/Ipkts (~ 1.7%).
Name  Mtu   Net/Dest     Address      Ipkts      Ierrs Opkts       Oerrs     Collis    Queue
qfe1  1500  10.0.0.0     10.0.0.3     1430247    24663 1779341     0         0         0

CHANGELOG

2007/07/10 -- Added e1000g interfaces
2006/11/29 -- Added dmfe interfaces, fixed bge and ce interfaces, many other modifications and fixes.
2006/04/27 -- Solaris 7 and earlier include subinterface information with netstat -i. Patch by Royce Williams to only query physical NIC interfaces.2006/03/09 -- Fixed bge interfaces, added support for iprb interfaces, added "support" for le interfaces, modified script to only require root access if using /usr/sbin/ndd to determine NIC speed and duplex settings2005/05/25 -- Fixed ce interface handling.2004/09/15 -- Added support for ce and bge interfaces.