ifconfig strange output

[gben]

Can anyone tell me why the eth0 interface is aliased as eth0:0? The OS is RedHat Linux 7. Thanks.

eth0 Link encap:Ethernet HWaddr 00:40:05:E2:6C:39
inet addr:219.217.191.17 Bcast:219.217.191.63 Mask:255.255.255.192
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:32967 errors:0 dropped:0 overruns:0 frame:0
TX packets:27462 errors:0 dropped:0 overruns:0 carrier:0
collisions:399 txqueuelen:100
Interrupt:12 Base address:0xa400

eth0:0 Link encap:Ethernet HWaddr 00:40:05:E2:6C:39
inet addr:219.217.191.17 Bcast:219.217.191.17 Mask:255.255.255.255
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:12 Base address:0xa400

 

[ifincham]

Hi,

On Redhat, the network start-up script reads files in /etc/sysconfig/network-scripts. For example, /etc/sysconfig/network-scripts/ifcfg-eth0 would contain data on the eth0 interface. The simplest way of creating a persistent aliased interface is to create a similar file called /etc/sysconfig/network-scripts/ifcfg-eth0:0 (i.e. copy the ifcfg-eth0 file) and edit that the way you need it to look.

I could only guess that you have such a file on your system although why is another question if you didn't put it there. Seems very odd because it shows the same IP address as eth0 and the reason for interface aliasing is so that you can have multiple IP addresses on a single network card. Maybe theres some kind of editor backup file of the ifcfg-eth0 file and thats being actioned by the start up script.

Hope this helps

 

[gben]

you are right. don't know how and why it got there. but thanks a mill for the help. merry christmas and happy new year!

-rwxr-xr-x 1 root root 355 Mar 10 2001 ifcfg-eth0
-rw-r--r-- 1 root root 34 Mar 10 2001 ifcfg-eth0:0
-rwxr-xr-x 1 root root 355 Mar 10 2001 ifcfg-eth1
-rw-r--r-- 1 root root 34 Mar 10 2001 ifcfg-eth1:0