Higher Education

We been looking at making some changes to our current DHCP / IP segments setup and would like to get some feedback on how most of you have your DHCP setup

 

I have a couple questions that might help us out go in the right direction

 

What type of server are you guys using ? Is it load balanced ? 50/50 or 100% ?

 

Are you guys using /22 , /23 ?

 

Lease time ?

 

How many wireless users ?

 

Using VLAN pooling hash or even ?

 

IPv6 ?

 

 

 

 

 

 

 

What type of server are you guys using ? Is it load balanced ? 50/50 or 100% ?

We are using Bluecat Adonis dhcp servers. Each of the 2 claim half the pool and regularly balance the available leases between them.

Are you guys using /22 , /23 ?

We use /23s in the majority of locations. I'd use /22s if we were using RFC1918 space.

How many wireless users ?

Roughly 42,000 concurrently; about 110K to 120K unique each week.

Using VLAN pooling hash or even ?

Hash.

IPv6 ?

Not yet, but wish were already. I'm very curious if others are today, and would specifically ask:
1.) dual stack or v6 only?
2.) what equipment are using for NAT64?
3.) what challenges have you encountered?
4.) what ArubaOS version?

Thanks Ryan

 

What type of server are you guys using ? Is it load balanced ? 50/50 or 100% ?

Cisco Registrar, 100%.  Upgrading to new version soon though, and hopefully we will be using what I think Cisco calls 

 "one-lease-per-client" by using Mac-address for client identifier.  On this current version for some reason we could not do it (I am not the DHCP admin), and we had a couple of mis-behaving users eating up a ton of IPs, depleting a particular subnet on the pool.  And since the vlan pooling algorithm happens before a client requests an IP, clients were still placed on this subnet with no IPs left.   The mis-behaving client was basically requesting IPs and declining them.  Both times Mac OS X machines.

 

Are you guys using /22 , /23 ?

/24 for public ip subnets, and /22 for private IP subnets.

 

Lease time ?

We played with this a lot, and decided on 30 minutes.

 

How many wireless users ?

7000 simultaneous, about 10-12 unique

 

Using VLAN pooling hash or even ?

 hash

 

IPv6 ?

Not yet..

 

Ryan, 42k concurrent users?  wow!

What type of server are you guys using ? Is it load balanced ? 50/50 or 100% ?

Load balanced.

 

Are you guys using /22 , /23 ?

3x/23, 8x/22 and 1x/21

 

Lease time ?

Somethimes changes. At top times 30 minutes. Other times 2 hours. By the way we are monitoring the usage. 

 

How many wireless users ?

At top 7K but usually 4k.

 

 

Using VLAN pooling hash or even ?

hash. 

 

IPv6 ?

 We are ready but not yet. We made all trials and decided not use yet (2 years ago).

What type of server are you guys using ? Is it load balanced ? 50/50 or 100% ?

We use Microsoft DHCP Server that comes with Windows 2008 R2.  We have 4 major campuses and use a separate DHCP server for each campus.  We do not load balance.

 

Are you guys using /22 , /23 ?

We actually use a DHCP Pool - 16 separate /24 subnets for each campus.

 

Lease time ?

We had to lower our lease time to 4 hours.  This seems to work well for our environment.

 

How many wireless users ?

Yesterday's count was 3900 simultaneous users.

 

Using VLAN pooling hash or even ?

Hash

 

IPv6 ?

IPv4 only.

 

Hope this helps!

Thank you guys