Highly available DHCP sevice

Hi,

I'm wondering how to make a highly available dhcp service within my
network using RedHat 9. I currently have dhcpd up and running with
thousands of clients without any problems but a recent event involving
a hardware failure exposed this as a single point of failure.

We using a class B network divided up into many class C networks and
all of our routers (Cisco) are configured to forward dhcp requests to
the dhcp server. It's working well but I really would like to have a
second dhcp server in active or standby mode that can automatically
take over in the event of a hardware failure. Does dhcpd have any
built in facility for this? Or what would happen if I had two dhcp
servers rsynced on the same network?

I'm not sure if this the right group for this. If it's not pointing
me in the right direction would be appreciated.

Thanks



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http://www.isc.org/products/DHCP/dhcp-v3.html

DHCP (open) source code.

Includes - DHCP Failover Protocol support

from the RFC-draft (in the source bundle)

" 1. Implementations of this protocol must work with existing DHCP
client implementations based on the DHCP protocol [1]."

So the magic is in the daemon, and should work with all clients.

You're Welcome.
Phil P

In article <(E-Mail Removed)>, (E-Mail Removed) says...
> Hi,
>
> I'm wondering how to make a highly available dhcp service within my
> network using RedHat 9. I currently have dhcpd up and running with
> thousands of clients without any problems but a recent event involving
> a hardware failure exposed this as a single point of failure.
>
> We using a class B network divided up into many class C networks and
> all of our routers (Cisco) are configured to forward dhcp requests to
> the dhcp server. It's working well but I really would like to have a
> second dhcp server in active or standby mode that can automatically
> take over in the event of a hardware failure. Does dhcpd have any
> built in facility for this? Or what would happen if I had two dhcp
> servers rsynced on the same network?
>
> I'm not sure if this the right group for this. If it's not pointing
> me in the right direction would be appreciated.
>
> Thanks
>
>
>
> .................................................. ..............
> Posted via TITANnews - Uncensored Newsgroups Access
> >>>> at http://www.TitanNews.com <<<<
> -=Every Newsgroup - Anonymous, UNCENSORED, BROADBAND Downloads=-
>
>

I.E. wrote:
> Hi,
>
> I'm wondering how to make a highly available dhcp service within my
> network using RedHat 9. I currently have dhcpd up and running with
> thousands of clients without any problems but a recent event involving
> a hardware failure exposed this as a single point of failure.
>
> We using a class B network divided up into many class C networks and
> all of our routers (Cisco) are configured to forward dhcp requests to
> the dhcp server. It's working well but I really would like to have a
> second dhcp server in active or standby mode that can automatically
> take over in the event of a hardware failure. Does dhcpd have any
> built in facility for this? Or what would happen if I had two dhcp
> servers rsynced on the same network?
>
> I'm not sure if this the right group for this. If it's not pointing
> me in the right direction would be appreciated.
>

The DHCP client has to be prepared to multiple willing servers. It's
up to the client to pick the preferred server from those responding.

For details, see RFC 2131.

Just set up another server. The only real problem is to prevent the
servers from assigning conflicting addresses - probably you have to
partition the address space between the servers, or assign client
addresses based on the clien identifier or MAC address.

HTH

Tauno Voipio
tauno voipio @ iki fi