ifconfig
syntax: ifconfig [interface] option
Examples:
ifconfig eth0 192.168.1.50
ifconfig eth0 down
ifconfig eth0 up
ifconfig is used to configure the kernel-resident network interfaces.
ifconfig with no argument/option, displays the status of the currently active interfaces.
ifconfig -a #Displays status of all NICs
ifconfig is obsolete in RHEL6, replaced by:
ip addr
or
ip link
For statistics use:
ip -s link
How to mount stuff in Linux
Mounting a CDROM:
1. Make a mount point in /mnt directory
mkdir /mnt/cdrom
2. Mount the CDROM
mount /dev/cdrom /mnt/cdrom
To verify, Type: mount
display should include:
/dev/sr0 on /mnt/cdrom type iso9660 (ro)
To mount a DVD or CD .iso file:
mkdir /mnt/dvdiso # Create a folder for the mount point
mount -ro loop /tmp/iso_file.iso /mnt/dvdiso #assuming the iso file is located in /tmp
How to restore Grub on RHEL6
Red Hat Enterprise Linux 6 – How to restore Grub.
1. Boot from RHEL6 DVD.
2. Select “Rescue installed system”.
3. Choose -> Language, Keyboard, and Rescue Method. Select “Local CD\DVD” for the Rescue Method.
4. Setup Networking -> Yes or No, doesn’t matter for restoring Grub.
5. Next on the “Rescue Screen”, select Continue and OK twice.
6. Next on the “First Aid Kit quickstart menu”, select “shell Start shell”.
The prompt will start:
Starting shell…
bash-4.1#
7. Type: “chroot /mnt/sysimage”
8. Type: “cd /boot/grub”
9. Type: “fdisk -l” to see where hd0.
10. Restore Grub, type: “grub-install /dev/sda1”
If No error, it should display:
# this device map was generated by anaconda
(hd0) /dev/sda