Dhcp

Mikdilly

One more from mspress book, chapter 7, page 7-6, tip box says 'When a dhcp server uses a given scope to assign addresses to clients..., dhcp server interface facing that segment must be assigned a static address within the same subnet range .'
Couple pages later on 7-9, another tip box says to make sure static ip address of dhcp server is 'either outside of, or excluded from, the range of the configured scope.'
Do they mean outside of, or excluded but within the same subnet range?

dynamik

Yes, the interface will need an IP on the same subnet, but you want it outside of the pool or excluded, so it does not assign the same IP to another machine.

skrpune

My understanding is that the static address needs to not be contained within the address scope range but does need to be within the same subnet range. You manually set the scope of addresses which are to be manually assigned, and if the static IP address you assigned to the DHCP server is within that scope, then you'll have addressing conflicts.

So they're right to say that you need to select a static IP address that is outside the scope...BUT it needs to be on the same network segment/subnet range otherwise it won't be able to perform the job. For example if you have a DHCP server static address of 192.168.1.1, you need to set your scope to be 192.168.1.x-192.168.1.x, rather than 192.168.2.x, etc.

EDIT: dang nabbit, I've been beat by dynamik again...I either have to learn to type faster or be more brief!

Mikdilly

Thanks, seems like they could have been a little more clearer in the book, one page says to configure the address of the dhcp server within the range and then a page later they say to make sure the address is configured outside of the range.

royal

Read my article here:
Scope vs Superscope | Elan Shudnow's Blog

I talk about exactly this and how to use a superscope to overcome it.

jbaello

royal wrote: »

Read my article here:
Scope vs Superscope | Elan Shudnow's Blog

I talk about exactly this and how to use a superscope to overcome it.

Nice blog Royal, has anyone actually tried setting up additional virtual IP on one physical interface TCP/IP to accomodate multiple DHCP scope? there's more overhead to it than just setting up a superscope but just curious.

I've seen an environment that uses superscope, hosts are able to get an IP address just fine the 1st time it gets plugged, but when a particular host moves to a different segment it keeps getting the original DHCP lease it has, as a result network connectivity is not working properly.

Mikdilly

Another topic in dhcp is setting up User Classes, can't get a handle on binary string or ASCII, in another post they were descibed as:

"The ASCII 'or' binary value must be filled for a class ID and must match the ASCII or binary string at the clients that must join that class."

What would you use to lookup the ASCII or binary string on the client and wouldn't these 2 things be unique on every client?