HP-UX 11i Version 1 Installation and Update Guide, December 2004

Configuring Built-In PCI Networking
1000Base-T (Gigabit Ethernet)
Appendix D 191
• edit the configuration file in /etc/rc.config.d/using an editor
such as “vi.” Depending on your driver, the filename can be
either hpgelanconf, hpigelanconf, or hpietherconf.
Set the mtusize by editing either HP_GELAN_MTU[0]=mtusize,
HP_IGELAN_MTU[0]=mtusize, or
HP_IETHER_MTU[0]=mtusize, and insert the proper interface
name: HP_GELAN_INTERFACE_NAME,
HP_IGELAN_INTERFACE_NAME, or
HP_IETHER_INTERFACE_NAME. When the system reboots,
the interface will be configured for jumbo frame operation.
3. Verify MTU change by executing: netstat -rn. If MTU has not
changed, execute the following commands:
ifconfig lan PPA_number unplumb
ifconfig lan PPA_number ip_address netmask netmask up
4. To check (or verify) the current Ethernet frame size, execute:
lanadmin -m PPA_number
Alternative way to temporarily configure jumbo frame size: Execute:
lanadmin -M mtu_size PPA_number.
The PPA number is the one we obtained from the output of lanscan.
For jumbo frames set the mtu_size to 9000 (bytes). Note: using lanadmin
will not preserve your settings across reboots.