Novell LINUX ENTERPRISE SERVER 10 SP2 - INSTALLATION AND ADMINISTRATION Installation Manual page 616

tunnel
This object represents a tunnel over IP.
If no command is given, the default command is used, usually list.
Change the state of a device with the command ip link
set device_name command. For example, to deactivate device eth0, enter ip
link seteth0 down. To activate it again, use ip link seteth0 up.
After activating a device, you can configure it. To set the IP address, use ip addr
add ip_address + dev device_name. For example, to set the address of the
interface eth0 to 192.168.12.154/30 with standard broadcast (option brd), enter ip
addr add 192.168.12.154/30 brd + dev eth0.
To have a working connection, you must also configure the default gateway. To set a
gateway for your system, enter ip route get gateway_ip_address. To
translate one IP address to another, use nat: ip route add
nat ip_address via other_ip_address.
To display all devices, use ip link ls. To display the running interfaces only, use
ip link ls up. To print interface statistics for a device, enter ip -s link
ls device_name. To view addresses of your devices, enter ip addr. In the output
of the ip addr, also find information about MAC addresses of your devices. To show
all routes, use ip route show.
For more information about using ip, enter ip help or see the ip(8) man page. The
help option is also available for all ip objects. If, for example, you want to read help
for ip addr, enter ip addr help. Find the ip manual in /usr/share/doc/
packages/iproute2/ip-cref.pdf.
Testing a Connection with ping
The ping command is the standard tool for testing whether a TCP/IP connection works.
It uses the ICMP protocol to send a small data packet, ECHO_REQUEST datagram,
to the destination host, requesting an immediate reply. If this works, ping displays a
message to that effect, which indicates that the network link is basically functioning.
598 Installation and Administration