Monday, December 13, 2010

configure network card on RHEL

Edit configuration files stored in /etc/sysconfig/network-scripts/

You can configure network card by editing text files stored in /etc/sysconfig/network-scripts/ directory. 

First change directory to /etc/sysconfig/network-scripts/:
# cd /etc/sysconfig/network-scripts/
You need to edit / create files as follows:
  • /etc/sysconfig/network-scripts/ifcfg-eth0 : First Ethernet card configuration file
  • /etc/sysconfig/network-scripts/ifcfg-eth1 : Second Ethernet card configuration file
To edit/create first NIC file, type command:
# vi ifcfg-eth0
Append/modify as follows:

# Intel Corporation 82573E Gigabit Ethernet Controller (Copper)
DEVICE=eth0
BOOTPROTO=static
DHCPCLASS=
HWADDR=00:30:48:56:A6:2E
IPADDR=10.10.29.66
NETMASK=255.255.255.192
ONBOOT=yes

Save and close the file. Define default gateway (router IP) and hostname in /etc/sysconfig//network file:
# vi /etc/sysconfig/network
Append/modify configuration as follows:
NETWORKING=yes
HOSTNAME=www1.nixcraft.in
GATEWAY=10.10.29.65

Save and close the file. Restart networking:
# /etc/init.d/network restart

Make sure you have correct DNS server defined in /etc/resolv.conf file:
# vi /etc/resolv.conf
Setup DNS Server as follows:
nameserver 10.0.80.11
nameserver 10.0.80.12
nameserver 202.67.222.222

Save and close the file. Now you can ping the gateway/other hosts:
$ ping 10.0.80.12
Output:
PING 10.0.80.12 (10.0.80.12) 56(84) bytes of data.
64 bytes from 10.0.80.12: icmp_seq=1 ttl=251 time=0.972 ms
64 bytes from 10.0.80.12: icmp_seq=2 ttl=251 time=1.11 ms

You can also check for Internet connectivity with nslookup or host command:
$ nslookup cyberciti.biz
Output:
 
Server:         10.0.80.11
Address:        10.0.80.11#53

Non-authoritative answer:
Name:   cyberciti.biz
Address: 75.126.43.232

You can also use host command:
$ host nixcraft.in
Output:
 
nixcraft.in has address 75.126.43.232
nixcraft.in mail is handled by 10 mail.nixcraft.in.
 
source http://www.cyberciti.biz/faq/rhel-centos-fedoracore-linux-network-card-configuration/print/?k=true&r_POST_P_HELPER_ID=530