HP-UX HB v13.00 Ch-09 - Networking Basics
HP-UX Handbook – Rev 13.00 Page 9 (of 27)
Chapter 09 Network Basics
October 29, 2013
or network.
The systems store the corresponding information within the routing table and we can have a look
at this information with the netstat command:
# netstat –rn
The kernel will refer to this list, when deciding which interface to use to send out a network
package.
To interpret the output you should consult the man page:
# man routing
The route command is used to (re-)configure the routing table on a running system. To make
permanent changes (that survive a reboot) enter the changes into the file,
/etc/rc.config.d/netconf, (using vi or SAM/SMH).
Good to know…
The initialization of an interface with the ifconfig command creates two entries within the
routing table of the system:
One host route to the new local IP.
One network route to the subnet the IP belongs to.
The source IP of a package of an outgoing connection will be determined by the routing table
(HP-UX 11.X). This might result in funny effects on systems where additional IP addresses on
virtual interfaces are defined (e.g. lan0:1).
When initializing the interface, net and broadcast addresses can be specified at the same time. If
this information is missing, then the system defaults will be used. The current values used by the
system can be checked, using:
# ifconfig <interface> also shows netmask and broadcast address
# netstat -in also shows the net addresses
# netstat -rnv also shows net addresses and netmasks
Starting with HP-UX 11.00, systems use the so-called Dead Gateway Detection mechanism the
active gateways in the routing table are pinged regularly to check whether they are still active or
not. If the gateway does not answer, then the appropriate entry is deactivated (marked “DEAD”).
As a result, devices like firewalls or routers, which do not answer to ICMP-ECHO-REQUESTS,
cause problems. To deactivate this feature use the command:
# ndd -set /dev/ip ip_ire_gw_probe 0
Commands and Utilities:
Below is an overview of useful commands and tools.
Basic Configuration Commands