Setting Solaris Network Tunable Parameters

Contributed by indianboy May 17, 2004  
Tagged: Solaris networking

To view the Network tunable parameters on a Solaris machine, we can use the following commands

bash-2.03# ndd -get /dev/hme ? | pg
? (read only)
transceiver_inuse (read only)
link_status (read only)
link_speed (read only)
link_mode (read only)
ipg1 (read and write)
ipg2 (read and write)
use_int_xcvr (read and write)
pace_size (read and write)
adv_autoneg_cap (read and write)
adv_100T4_cap (read and write)
adv_100fdx_cap (read and write)
adv_100hdx_cap (read and write)
adv_10fdx_cap (read and write)
adv_10hdx_cap (read and write)
autoneg_cap (read only)
100T4_cap (read only)
100fdx_cap (read only)
100hdx_cap (read only)
10fdx_cap (read only)
10hdx_cap (read only)
lp_autoneg_cap (read only)
lp_100T4_cap (read only)

output truncated…..

The ( read and write ) parameters are the ones that can be changed on the system

You should be root to change the parameters and the changes will be temporary .

for example lets take a common example

# ndd -get /dev/hme link_speed
1
#

Here it is specified that the link_speed (ethernet is 100Mbps). To change that to 10Mbps

we can do the following

# ndd -get /dev/hme link_speed ( present condition)
1
#
# ndd -set /dev/hme instance 0 ( if there is only one nic then no issues )
# ndd -set /dev/hme link_speed 0
# ndd -get /dev/hme link_speed
0
#

This is just an example other interesting parameters that can be changed are the ip_forwarding feature, which were normally carried out on firewalls. Now it is done by the firewalls during installation.

Anyway the command is

#ndd -set /dev/ip hme0:ip_forwarding 0
#ndd -get /dev/ip hme0:ip_forwarding
0
#

A value of 0 specifies a disabled condition.

Interesting Modules are

/dev/ip
/dev/hme

For making the changes permenant, make entries in the /etc/system file.