Q. I am using Ubuntu Linux and I would like to know how to create alias for eth0 so that I can have multiple IP address?
A. To create alias for eth0 use ifconfig command. It is use to configure a network interface and aliases.
Assuming that your eth0 IP is 192.168.1.10 and you would like to create an alias eth0:0 with IP 192.168.1.11. Type the following command:
sudo ifconfig eth0:0 192.168.1.11 up
OR
sudo /sbin/ifconfig eth0:0 192.168.1.11 up
Verify that alias is up and running using following two command(s):
/sbin/ifconfig
ping 192.168.1.11
ping your-getway-ip
Permanent configuration
Your ethernet configuration is located in a file called /etc/network/interfaces. If you reboot system you will lost your alias. To make it permanent you need to add it network configuration file:
gksudo gedit /etc/network/interfaces
OR
sudo vi /etc/network/interfaces
Append the following configuration:
auto eth0:0
iface eth0:0 inet static
name Ethernet alias LAN card
address 192.168.1.11
netmask 255.255.255.0
broadcast 192.168.1.255
network 192.168.1.0
Save the file and restart system or restart the network:
sudo /etc/init.d/networking restart
Please note that you can also use graphical tools located at System > Administration > Networking menu. Or use the following GUI tool to setup aliases, hostname, dns settings etc:
sudo network-admin
If you want more network aliases, use eth0:1, eth0:2, eth0:N (max upto 254).
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{ 20 comments… read them below or add one }
/sbin/infconfig
There’s no such command. Fix the typo ;)
kotnik,
Err…
thanks for heads up :)
Thank you so much for this guide! It is easy to understand.
simple and good guide. Thank you.
What if you don’t use a permanent ip address and
rely on DHCP to assign the IP address?
Is this correct?
sudo ifconfig eth0 up
Do I need to setup dhcp?
what does mean this line:
name Ethernet alias LAN card
i look into man interfaces, but can’t found about name syntax
thx
i solve my problem of multi addresses.
Hi All,
This is a very good site to linux learner.But how can i post my query to get resolution.
Jayesh,
Use our Linux support forum
When creating an alias, must it be in the same subnetwork?
To explain better, if my ip address id 1.1.1.1/255.255.255.0, the alias must be 1.1.1.x or can it be 2.x.x.x?
thanks
This link might be somewhat useful for aliasing an interface using programming.
Link
Why we can’t use more than 254 aliases on a NIC?
If i am using 2 NICs in my box, will the max. limit be 508?
Hello,
Can I manually add IP to /etc/network/interfaces ?
Can someone post an example of multiple IP addresses on one NIC ?
thanks
Hell there. I am a new Linux user, more specifically Ubuntu. I was confused what was meant be the following line – “name Ethernet alias LAN card”. Is this the physical device name or just eth0?
Any help with this would be great thanks.
Thanks for the helpful tip.
That is exactly what I have in my file… including the auto eth0:0. However, it looks like the auto is not that automatic on a reboot. Have you had problems on a reboot? Wondering because I’ve seen many people running in the problem of the 2nd IP disappearing after the machine is restarted.
Thank you, Alexis
I have the same problem as Alexis Wike, Did anyone come up with a solution for this. After reboot the eth0:0 does not comeup. The auto eth0:0 line is there in the file but it seems that it does nothing. Thanks
Hi all,
Thanks!
Can you please tell me why there is limit to create an alias for NIC?
How many IP’s we can assign to a single NIC any Why???
regards,
Mitter Singh Thakur
System Admin
+91-7737603000 | +91-8890152367 | mitter1989@gmail.com
Mitter,
Yes. The limit is something like 254. It one byte. 0 and 255 cannot be used or something like that.
Alexis
The reason you may be having problems w/ AUTO on an alias is that you are not allowed to use anything other than the default subnet for the ip range in question.
(Example: 10.x.x.x uses a default subnet of 255.0.0.0) If you try to assign any other subnet mask to the aliased ip, it won’t let you, and will take down the interface instantly. (Also true if you use ifconfig to assign the netmask).
Kind of ruins the point needing things like a server w/ several 10.x.x subnets, and forces one to use 192.168 addresses for 255.255.255.0.
Which would be fine if one didn’t already have a complex subnetted 10.x.x.x set of ranges in place because 192.168 doesn’t have enough subnets.
Really annoying that.