Running new dhcpd instance on same physical interface

[Simon Hobson]

Dario Aguilar wrote:

>Hi, I understand your point. Our idea is to isolate different kind of
>services/clients such as DSL, Wimax, IPTv, etc.. into different instances of
>dhcpd, we have many reason to do this (with just 1 box): Eg.
>Troubleshooting, availability, separate same subnets on diff. instances,
>etc...

I think you'll find troubleshooting easier with one instance.

If one of the issues is to segregate control 
among different departments, I believe what some 
large users do is have their configs 'machine 
built'. Keep a database of the required config, 
and have a script that builds the new config, 
tests it, and makes it live. Done this way, you 
can use access controls in the database system to 
control who can change what.

>In fact none of this CPE´s are directly connected to the dhcp server
>(I mean on the same broadcast domain) so, the server will never receive any
>broadcast packets. Instead of that it will receive forwarded packets from
>several DHCP Relay´s (unicast traffic) for each service such as DSLAM´s,
>WAC´s, etc..

When the server architecture was laid down, it 
was assumed that it would always "handle" any 
local interfaces it listens on. So even if all 
clients are connected via relay agents, the 
server still listens for broadcasts on the local 
interface. This has other ramifications as well - 
it means the server only works on certain types 
of interface. One of those design decisions that 
would probably be different if starting from 
scratch today, but probably valid when it was 
first made.

>I will appreciate very much if you have a better idea or another suggestion
>on how to resolve this without adding another physical interface that in
>fact it will be connected to the subnet that the other one.

I don't have any other good ideas.


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Simon Hobson

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