6 Nov
2012
6 Nov
'12
7:57 a.m.
On Tue, 6 Nov 2012, Schindler Patrik wrote:
DHCP is not a must-have. I'm running DNS on my
Linux-Box in my LAN, so I
don't want to have dynamic IP addresses. There's only a small
DHCP-Range, just for "guest boxes", for netbooting XTerminals or my G5
when I need to run Disk First Aid, for a fast installation of Debian on
friend's boxes. Any static (in terms of will-not-be-moved) machine has
static IP-Adresses configured. I don't get the point why machines, which
don't change networks (like a notebook, taken from place to place), need
DHCP. Avoiding IP collisions? Is a matter of documentation. For me, my
documentation is the DNS zone files.
DHCP may not be a "must have", but for any machine, old or new, it can
make it /much/ easier to manage a large number of systems and other
network-enabled devices, especially if you move or swap systems and
equipment out at random such as many of us do. For non-guest machines, I
don't use a dynamic range of addresses, I use DHCP to assign static IP
addresses for specific MAC addresses. When (not if) I reconfigure subnets,
gateway addresses, hostnames, etc, I don't have to modify the
configuration on dozens upon dozens of different machines. That said, ISC
DHCP's configuration has a steep learning curve, but once you get it down,
it is incredibly easy to modify or add to later (and yes, I run my own
DNS, too).
Another thing I found helpful is to run a separate test/sandbox network on
192.168.1.0/24 with parts of the range dynamically assigned. I then have
some of my local network segments configured so that any connections to
192.168.1.x are NAT'd as 192.168.1.100 on this segment. This is incredibly
useful because tons of networking gear comes preconfigured with static
192.168.1.x addresses, and in default configuration it won't talk to a
machine that doesn't have a 192.168.1.x IP address. This setup allows me
to plug something in, update/configure it, and then unplug and move it
right over to the correct subnet (where DHCP usually then takes over).
Just for the record, the machine I'm currently using for DHCP has 16
ethernet interfaces, although currently I'm only using 9 or so. My setup
isn't typical, but really anyone could do something similar and scale it
down or up as needed.