Re: DHCP server fail-over and accounting

[John Adams <jna () retina net>]

2011/2/1 Joe <sj_hznm () hotmail com>:
> hi,
>
>    we plan to implement DHCP server farm in our network.   Currently , there are there  problems burning my head. 
> could anybody


You're making this way, way too complicated.

Run two DHCP servers. Allocate two different netblocks to each server.
For Example, if your network is a /24, allocate a couple of /26's.
Both will answer on a request.
The client will ack to whatever address it decides to accept. Full redundancy.

>       To our experience, this needs to set up  DHCP  server on two sites and syncronize their content in real time.
>      Beside this ,  we hope  there should be as less modification as possible  on edge router when one DHCP  server 
> is down.
>      should anycast architecture helpful ?   or should we just set up two dhcp servers on two sites and  sync. with 
> ISC DHCPD?

Don't even bother with the syncing, and anycast is the wrong protocol here.

>  2. How to set up accouting and authentication with DHCP?

That's the wrong place to do it.  802.1X is better here, or PPPOE/ACLs
that need RADIUS auth to get past.

> 3.  Someone said PPPOE is not good for customer looking for long time online ,  DHCP is an good option.  But, to my 
> understanding

That's funny, because many major ISPs (like telcos) have done this for years.

-j