Re: Please help with IP Aliasing
First of all thanks a lot for your fast help, especially to Craig!
> firstly, replace all those ifconfig & route commands with something like
> while [ $i -le 254 ] ; do
> ifconfig eth0:$i XXX.231.206.$i netmask 255.255.255.0
> route add -host XXX.231.206.$i eth0:$i
> $i=$(( $i + 1 ))
Good idea! A lot easier to read that way.
>From your answers I assume that I really have to setup a virtual
interface for every IP address. Isn't there a possibility to
map a whole subnet XXX.231.206.everything? I thought I saw that
on a system a while ago. It had even more IP addresses assigned
to. But it might have been a FreeBSD system.
> secondly, the route command is optional.
How come that I can't reach my own address(es) without a route?
Shouldn't it be routed to the gateway, which would send it back
to my machine?
> third: do you *really* need all those aliases configured right now?
Nope, but soon.
> if not, then only configure the ones you actually need, *when* you need
Why? Does it have any negative effects to have that many interfaces and
> fourth: for a virtual hosting system, it's not terribly difficult to
> set things up so that the configurations for virtual web, ftp, mail,
> dns, and ip_aliasing are all controlled from one file. e.g. make a file
> called /etc/virtual-hosts which contains the following info:
I like that idea. I'll probably set things up this way as soon as I
have more time again.
> you can increase this limit by modifying the kernel sources. or start
> using 2.1 series kernels.
Are you saying that 2.1 kernels have this limit set higher or are they
using a completely different way of handling this situation?
> if you've got more than 255 virtual hosts then you probably want another
> machine to host them on anyway. don't try to make one machine do too
I am sure linux can handle it. :-) No, seriously, more IP addresses
doesn't necessary mean more traffic. It's just that some customers
want their own domain which has to be mapped to a separate IP number.
Thanks again for your help!
Andy Spiegl, University of Technology, Muenchen, Germany
E-Mail: Andy@spiegl.de URL: http://www.spiegl.de
PGP fingerprint: B8 48 24 7B DB 96 6F 1C D9 6D 8E 6C DB C2 E7 E9
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