Excluding a range of ip addresses from dhcp

[Process153]

Hi all,

Was wondering... Say I have a dhcp scope that issues addresses in the range 100.10.0.1 to 100.10.127.254 but I want only PC's to get addresses in the 100.10.0.x subnet.  Is there anyway to restrict this?  At the moment, some users get a 100.10.1.x address.

Thanks!

[Mark Malone · Accepted solution]

Hi

If the DHCP process is coming off a Cisco router/switch you can do an ip dhcp excluded range set

You can exclude the whole range of 10.100.1.x addresses so the pool doesn't give out any from that range specified , you can have as many lines as it takes or do exclude all at once if possible

ip dhcp excluded-address 100.10.1.1 100.10.1.254

example

http://www.cisco.com/c/en/us/td/docs/ios/12_2/ip/configuration/guide/fipr_c/1cfdhcp.html#wp1001302

ip dhcp excluded-address 172.16.1.100 172.16.1.103 

ip dhcp excluded-address 172.16.2.100 172.16.2.103

!

ip dhcp pool 0

 network 172.16.0.0 /16

 domain-name cisco.com

 dns-server 172.16.1.102 172.16.2.102

 netbios-name-server 172.16.1.103 172.16.2.103 

 netbios-node-type h-node

!

ip dhcp pool 1

 network 172.16.1.0 /24

 default-router 172.16.1.100 172.16.1.101 

 lease 30 

!

ip dhcp pool 2

 network 172.16.2.0 /24

 default-router 172.16.2.100 172.16.2.101 

 lease 30

[Process153]

Awesome! Thank you both

[gdspa]

I have a strange problem, with these exclusions

ip dhcp excluded-address 10.139.48.1 10.139.48.43
ip dhcp excluded-address 10.139.49.0 10.139.49.255
ip dhcp excluded-address 10.139.48.49 10.139.48.255

which should permit assignments of range 10.139.48.44...48, I have

gdit04nsw01#sh ip dhcp pool

Pool AP_pool :
Utilization mark (high/low) : 100 / 0
Subnet size (first/next) : 0 / 0
Total addresses : 510
Leased addresses : 0
Excluded addresses : 510
Pending event : none
1 subnet is currently in the pool :
Current index IP address range Leased/Excluded/Total
10.139.48.54 10.139.48.1 - 10.139.49.254 0 / 510 / 510

Do you know about any bug? I use WS-C3650-48PS with 03.06.06E

[Leo Laohoo]

Configuring the Cisco IOS DHCP Server

[francesco.martinelli]

Hi, need to exclude specific vendor (ipphone.mitel.com) with option 43 in my cisco dhcp configuration as this.

ip dhcp excluded-address 10.172.85.1 10.172.85.29
ip dhcp excluded-address 10.172.85.40 10.172.85.254
!
ip dhcp pool RETE-UNITARIA-COMUNALE
network 10.172.85.0 255.255.255.0
default-router 10.172.85.10
dns-server 10.172.200.41 10.172.200.42