FC2 and manual ip address setup

[Scot L. Harris]

On Fri, 2004-06-25 at 09:17, Jack Howarth wrote:
>      I have configured a linux box running FC2 to use static addressing.
> The machine was originally installed with FC2 to use dhcp and later I
> switched the addressing mode to static ip addressing from the network
> control panel. The system seems to have normal network access but I
> am perplexed by the contents of /etc/hosts which now are of the form...
> 
> 127.0.0.1       localhost.localdomain mydomainname.domain localhost mydomainname
> 
> Is this expected or a result of originally configuring the machine for dhcp?
> There appears to be no entry in /etc/hosts with the actual ip address of
> mydomainname.domain so I assume it is always gotten by dns. Thanks in
> advance for any comments as I want to make sure this is really the correct
> configuration for a static addressed machine.
>                        Jack

I see the same kind of entries in fresh installed FC2 boxes where I have
assigned a static IP during the install.

This did cause me a problem with one package (vhost) that manages
multiple virtual hosts on a box.  I had to change the /etc/hosts entry
to include the machines actual IP address followed by its real FQDN and
name.  The loopback address (127.0.0.1) was changed to just include the
localhost entries.

This resolved the problem I had with the vhost package.

Note: I use statically assigned IP addresses on all of my equipment
except for laptops.  

I believe when DHCP assigns the address you will find those changes in
the interface files but they are not translated into the /etc/hosts
file.  

IMHO DHCP is very useful for equipment like laptops which are moved from
LAN to LAN on a regular basis or for equipment linking your LAN to an
ISP where you do not have static IPs assigned.  If you are running
servers or significant amounts of equipment which remains on the same
LAN segment all the time then statically assigning IP addresses and
making the entries in the /etc/hosts file or DNS is the proper way to
manage such equipment.  Using DHCP in such cases could lead to various
problems including "loosing" a server because its IP address suddenly
changes or worse yet someone usurps your servers IP address and captures
sensitive data (passwords, email, etc.).  

In a production environment running DHCP gives someone a leg up since if
they can get access to your LAN they can plug any equipment into it and
get on the network with little effort.  If you assign IP addresses then
they have to know more information about your network before being able
to get on.  And yes it is fairly easy to attach a sniffer and figure out
the network addressing but it is another step someone has to take before
being granted access to do other things.

And in bigger networks when you start deploying network monitoring tools
having static IP addresses for critical equipment is IMHO required.  

-- 
Scot L. Harris
webid at cfl.rr.com

Sometime when you least expect it, Love will tap you on the shoulder...
and ask you to move out of the way because it still isn't your turn.
		-- N.V. Plyter