Adding aliases for static ip's alongside dynamic ip.*update*

ZiffyWombat · Last edited by ZiffyWombat on Wed Jul 20, 2005 12:25 pm; edited 1 time in total

Now, this is a good idea (or not, i don't know about it's security problems) if you only have one physical NIC on you're computer but if you have a second NIC then use it for your static ip,

So, if you seriously want to setup your NIC to handle both dynamic and static ip's insert these lines to your /etc/conf.d/net:
Example lines from my config.

planet-admin

ZiffyWombat · Posted: Wed Dec 22, 2004 8:37 pm Post subject:

planet-admin · Posted: Wed Dec 22, 2004 8:38 pm Post subject:

wharding · n00b Joined: 02 Nov 2004 Posts: 7

Is this a by product of multi-homing?

I thought you could multi-home a single nic card by setting multiple static IP addresses. Was never sure you could do it by using DHCP.

And in actuality I have never setup a multi-homed nic card, so I may be WAY off base here in the first place.

I should give this a try.

kimchi_sg · Advocate Joined: 26 Nov 2004 Posts: 2968

I wonder what this would be useful for.

If only i had a NIC with 2 ethernet ports to test this.

wharding · n00b Joined: 02 Nov 2004 Posts: 7

I don't think you need multiple ethernet ports. What it is useful for is pointing multiple IP addresses to a single NIC card. This way you could load balance the connection plus other fun and useful tricks.

Although, I think I might have had a bit more holiday cheer than I had intended so again I might bit a bit off base

mudrii · l33t Joined: 26 Jun 2003 Posts: 789 Location: Singapore

wow
nice howto
THX
_________________
www.gentoo.ro

Ox- · Guru Joined: 19 Jun 2003 Posts: 305

All I added to /etc/conf.d/net was:

lothar · Posted: Thu Dec 23, 2004 10:24 am Post subject:

I've used this for some time now. The DHCP recieves IP from my ISP, and I've got a local ip 192.168.0. to get in contact with the other computers in the house + my neighbour

NeddySeagoon · Posted: Thu Dec 23, 2004 10:49 am Post subject:

This sets up multiple logical networks over the same physical network
and is called aliasing.

Its not a good idea unless you have a switch to stop the 192.168.x,x packets getting into the internet. They are not publicly routable, so you may get a nastygram from your ISP.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

srlinuxx · l33t Joined: 22 Nov 2003 Posts: 627

RinkyDinks_RJ · n00b Joined: 12 Aug 2003 Posts: 42

Aliases, Subinterfaces, logical interfaces. They all mean the same thing. They are most commonly used for routing and switching purposes, but can be adapted to other uses.

Ateo · Posted: Fri Feb 11, 2005 10:05 am Post subject:

j-m · Retired Dev Joined: 31 Oct 2004 Posts: 975

It is perfectly normal and very useful to have many IP addresses on one NIC. Absolute must, if you need many web sites with their own certificate on one machine. This is what I have on a webhosting server:

DeathAndTaxes · Tux's lil' helper Joined: 27 Mar 2003 Posts: 124

Ok, it's nice to see that the gentoo init scripts now allow you to assign one via dhcp and one static, but there's some confusion in this thread about when/where this would be handy and such.

Firstly, you generally do *not* want to assign two IPs on the same subnet to one box...Whether they are aliases on one NIC or are two different NICs. You might not notice a problem, but I'd bet other boxes on the LAN would go crazy with their ARP caches. I did this a couple of times and had some weird problems...I think it's common for people to do this, but I've seen some strangeness in doing this.

***EDIT***Erm, I'm rethinking this. I know someone will point out my flaw, but I'm going to wait until they clarify my error before I respond.***END EDIT***

Second, you *can* add as many aliases (read: different IPs) to a nic as you like (well, almost...There are a few limitations, but the numbers are really large), but again, you do not want to have multiple IPs on the same subnet on one box.

***EDIT***Disregard the not having multiple IPs on the same subnet. My bad...I was thinking of something else. DOH!***END EDIT***

Third, the settings listed in the top post do not specify what the default route is if the DHCP fails. If the DHCP server hands out the default gateway (most do), then you're ok, but if the dhcp process fails, you don't have a default route defined.

Fourth, it's generally a good idea to set a timeout for dhcpclient...This can be set in /etc/conf.d/net on the dhcpcd_ethx lines. An example would be:

golding · Posted: Tue Jul 19, 2005 10:18 pm Post subject:

Would this be any good for getting a print server to be recognised?

I have an adsl router/dhcp server and an HP lan print server. Unfortunately the print server is static at 192.0.0.192 0n 255.255.0.0 while my lan is served from the dhcp on 10.0.0 and 255.255.255.0. I have not been able to browse to the print server, but, I don't want to try this if it is going to bork my connection to the net.
_________________
Regards, Robert

..... Some people can tell what time it is by looking at the sun, but I have never been able to make out the numbers.

ZiffyWombat · Posted: Tue Jul 19, 2005 11:11 pm Post subject:

A little update on this.. These days you can just use
for example.