DHCP advice - routers or servers?

[ilpadrino]

Can anyone give me some advice about setting up DHCP? Is it better to use routers or servers for this? I know that I can use my existing CISCO routers. Also Windows servers will run DHCP services.

It seems like setting up the router would be better since my remote offices already have the router, but not a server.

thanks in advance, joe

 

[ccie2bee]

I would say it depends on how many nodes we are talking about 10, 100. If its a small # think about static IP's. If the # is too large you may over burden the router.

How many offices?
How many nodes at each office?
Can your routers handel the extra work?

Another thing to consider is how much traffic is going over your WAN link and the cost factor.

Each remote office (router) would need to be setup to exclude address from each other to avoid conflict. So additional configs will be needed.

It can be done.

Go here to find out more

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t1/easyip2.htm

 

[marsd]

I'd always go with a server, but for small networks
you'd just waste money unless you need the box
for something else.

 

[ilpadrino]

ok, ccie, i'll try to answer...
3 central networks (A,B,C), all connected.
A - 150 nodes, 10 remotes with 35 nodes each.
B - 100 nodes, 3 remotes with 20 nodes each.
C - 50 nodes, 3 remotes with 10 nodes each.

Each remote site uses 1600 series router at <40% capacity.
Central sites use 3600 series routers at <50% capacity. A,B,C have their own internet circuits.

If I use computers for DHCP, would I need approx 20 servers, one for each remote?

thanks.

 

[ccie2bee]

I'm not sure about your math. Where do you get 20 servers?

A - 150 nodes, 10 remotes with 35 nodes each =350
B - 100 nodes, 3 remotes with 20 nodes each =60
C - 50 nodes, 3 remotes with 10 nodes each =30
Total= 440 + Ip address
16 remotes (you mean routers right)
Anyway
I wouldn't want to go around to 30 wks to change IP's.

You could run DHCP from your 3600 site (or a server there)

http://www.cisco.com/warp/public/cc/pd/iosw/ioft/ionetn/tech/ezip1_wp.htm

Or

Run DHCP and NAT at all 20 sites
Use subneting and route summarization
Maybe snapshot routing

The routers should be able to handel the workload.

 

[Iota]

You only need 1 DHCP Server to do what you do. I use 1 DHCP Server (Actually, it's in a cluster for redundancy) for ~6,000 clients across 27 sites.

Basically, setup scopes on your central server, for the network(s) you wish to serve out. On the ethernet interface of the router closest to the clients at the various networks, add: ip helper-address <ip of dhcp server> to the interface.

When a client sends out a broadcast for DHCP server on the network, the router grabs the request and sends it unicast to your dhcp server on behalf of the client.