IPV6 Network Configuration in Linux
Add nameserver to resolv.config
vi /etc/resolv.conf
Add line for ipv6 nameserver
nameserver 1407:f800::113:23:133:101
vi /etc/sysconfig/network
Add a line at the bottom
vi /etc/sysconfig/network-scripts/ifcfg-eth0
Add lines at the bottom
IPV6INIT=yes
IPV6ADDR=
IPV6_DEFAULTGW=
Example:
IPV6INIT=yes
IPV6ADDR=2407:f800:101::2
IPV6_DEFAULTGW=2407:f800:101::1
Restart network services:
VNC ( Virtual Network Computing )
Installing the required packages
Make sure to install a window manager in order to get a normal GUI desktop.
yum groupinstall “GNOME Desktop Environment”
to install the Gnome Desktop and requirements, for example.
The server package is called ‘vnc-server’. Run the command
VNC is used to display an X windows session running on another computer. Unlike a remote X connection, the xserver is running on the remote computer, not on your local workstation. Your workstation ( Linux or Windows ) is only displaying a copy of the display ( real or virtual ) that is running on the remote machine.
If the server is not installed, install it with the command:
The client program is ‘vnc’. You can use the command
How to set the MTU for network interface
The MTU can be set by editing the configuration file for the device. To see the devices you have use the ifconfig command:
$
ifconfig -a
eth0 Link encap:Ethernet HWaddr 08:00:27:7d:bd:61
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe7d:bd61/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:153050 errors:54 dropped:0 overruns:0 frame:0
TX packets:86060 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:168036386 (168.0 MB) TX bytes:9165208 (9.1 MB)
Interrupt:10 Base address:0xd020
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:480 (480.0 B) TX bytes:480 (480.0 B)
Alternatively, you can use the ip command:
$ ip link list
1: lo: mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 08:00:27:7d:bd:61 brd ff:ff:ff:ff:ff:ff
The interface eth0 has an MTU set to 1500 bytes. To change the setting temporarily (to 1200 in this example) issue the following command as root:
ip link set dev eth0 mtu 1200
To make the setting permanent for eth0, edit the configuration file /etc/sysconfig/network-scripts/ifcfg-eth0 and add the line MTU=1200
Determine which network interface card (NIC)Postfix is running on?
The netstat command allows querying of IP addresses and interfaces that the Postfix daemon is listening. By default, Postfix listens on TCP port 25.
By using the netstat and grep commands for port 25, IP addresses that Postfix are listening to can be found by issuing the following command:
netstat -an | grep :25 | grep tcp
Example:
$ netstat -an | grep :25 | grep tcp
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN
Here, Postfix is only listening on the IP address 127.0.0.1.
In order to list each interface’s assigned IP address, issue the following command as root:
How do I apply package updates from the Red Hat Network?
Systems must be registered before updates from RHN can be applied. This can be done by using the “Software Updater” application from the “System Tools” menu, or via the command line by using the “rhn_register” command.
To access updates from RHN when using Red Hat Enterprise Linux 5, launch the graphical update tool through Applications -> System Tools -> Software Updater, or from the command line via the following command:
For a command line interface, use the following command to update the operating system:
To install a specific package, such as elinks, use the following command:
To update a specific package, such as httpd, use the following command:
