[ILUG] IP Number - where is it held?

[Vincent Cunniffe]

"Ryan, Philip" wrote:
> 
> Hello Folks
> 
> We're looking for where LINUX stores it's IP address.
> 
> Our initial thinking was that /etc/sysconfig/network is sourced at boot time
> by /etc/rc.d/init.d/inet which uses the value of $HOSTNAME to do a lookup in
> /etc/hosts to establish the IP address.
> 
> This has proven to be false.
> 
> >From further investigation I'm concluding that LINUX is similar to AIX in
> that via SMIT on AIX, one adds or changes the IP address and this change is
> reflected in /etc/hosts & written to the ODM. Whereas on LINUX, one updates
> the IP address via linuxconf and this change is written to some binary
> somewhere but not reflected in /etc/hosts (feature in linuxconf-1.16r10-2
> ?????).
> 
> Any pointers on which file linuxconf writes to?

Linux, in general, avoids binary configs like the plague.

/etc/syconfig/network-scripts

is where you want to look... all editable manually.

One thing you might want to remember is that 'Linux' per se doesn't have
an IP address : interfaces of all kinds do, sometimes more than one address
per interface. So a single running linux kernel could have anywhere from 
zero to pretty much any number of valid IP addresses active at any time.

1 primary IP for a single ethernet card is most common though, found in
'/etc/sysconfig/network-scripts/ifcfg-eth0'.

Good luck,

Vin