ip dhcp excluded-address

Answered Question
Oct 13th, 2008

Hello, I just setup DHCP to hand out IPs to my LAN. Im not comfortable with

the exclusions in regard to what it says in the config and no also no available "show" commands to view excluded addresses. I googled this but did not find anything. I thought it would be a great topic for here. Here Is what I did and my questions below:

dhcp-router# conf t

dhcp-router(config)#service dhcp

Router(config)# ip dhcp pool DHCPPOOLNAME

Router(dhcp-config)#network 192.168.1.0 /24

Router(dhcp-config)#domain-name mydomain.com

Router(dhcp-config)#dns-server X.X.X.X X.X.X.X

Router(dhcp-config)#default-router 192.168.1.1

dhcp-router(dhcp-config)# netbios-name-server 192.168.1.12

Router(config)#ip dhcp excluded-address 192.168.1.1 192.168.1.99

Router(config)#ip dhcp excluded-address 192.168.1.201 192.168.1.254

After I configured this my exclusions were only visible to me

through "show run" Here is the output:

!

no ip dhcp use vrf connected

ip dhcp excluded-address 192.168.1.1 192.168.1.99

ip dhcp excluded-address 192.168.1.201 192.168.1.254

!

1. Why does it say "use vrf connected" ?

2. Are my exclusions going to work for my LAN ?

3. Is there a show command that gives a administrator the exclusions ?

Correct Answer by Jon Marshall about 8 years 3 months ago

Kyle

Please bear in mind that people on this forum do not get paid to give advice. They do it to help people out and these forums are known for their politeness and the willingness of the contributors to try and help.

Marwan has tried to answer your questions and it's perhaps not too surprising based on your responses to him that others have been less than keen to jump in.

Anyway that said NetPro is about giving help

1) You are not using vrf's. This line seems to be a standard line IOS puts into your config. If you were using vrf's it may be relevant.

2) Yes, why wouldn't they. I can't see a reason with the config you have supplied why they wouldn't.

3) No although "sh run | begin ip dhcp excluded" would get you to the bit you are interested in.

Jon

Correct Answer by MUHAMMAD SHAHEEN about 8 years 3 months ago

Hi Wesley,

1 it simply means excluded ip addresses are not part of dhcp database.

2 Yes, it will work

3 Because excluded addresses are not part of dhcp database, these are part of main config, can be seen in running config, using show runn or show runn | inc excluded

Hope this helps....

Shaheen

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 3.5 (4 ratings)
Loading.
Marwan ALshawi Mon, 10/13/2008 - 19:48

the excluded IPs

are the IPs that WILL NOT be allocated to any host through this dhcp service

but u assigne it to any host staticly and use it normaly

this is good to use it with defualtgateway, servers, network printers.. ets

any ip with the range of ur pool u assigne it staticly excluded from the dhcp pool to avoid any conflict

good luck

if helpful Rate

wesley.roberts Mon, 10/13/2008 - 19:55

1. Why does it say "use vrf connected" ? <---not answered

2. I assume your reply means I set it up correctly so Answer 2 has been fufilled.

3. Is there a show command that gives a administrator the exclusions ? <-----Not answered

Marwan ALshawi Mon, 10/13/2008 - 20:32

try

show ip dhcp dinding

show ip dhcp server statistics

i see it dose not use vrf !!

wesley.roberts Tue, 10/14/2008 - 14:08

Those two do not give me the "excluded IP ranges" darn it! I guess you can only find your exlusions by using the "sh run" and look in your config. Which brings us back to question:

1. Why does the running-config say "use vrf connected" when displaying the excluded ip ranges that I set?

Here are the answers to my previous questions for the sake of historical post integrity:

2. Are my exclusions going to work for my LAN ? <--No one answered

3. Is there a show command that gives a administrator the exclusions ? <--No one knows a command other then the "sh run" which we all knew.....

Final Summary: Still waiting on an Answer on question 1. Gave up on question 2 & 3

wesley.roberts Thu, 10/23/2008 - 14:10

Still waiting on Suggestions/Answers

1. Why does the running-config say "use vrf connected" when displaying the excluded ip ranges that I set?

2. Are my exclusions going to work for my LAN ?

3. Is there a show command that gives a administrator the exclusions ?

Correct Answer
MUHAMMAD SHAHEEN Thu, 10/23/2008 - 14:53

Hi Wesley,

1 it simply means excluded ip addresses are not part of dhcp database.

2 Yes, it will work

3 Because excluded addresses are not part of dhcp database, these are part of main config, can be seen in running config, using show runn or show runn | inc excluded

Hope this helps....

Shaheen

Correct Answer
Jon Marshall Thu, 10/23/2008 - 14:53

Kyle

Please bear in mind that people on this forum do not get paid to give advice. They do it to help people out and these forums are known for their politeness and the willingness of the contributors to try and help.

Marwan has tried to answer your questions and it's perhaps not too surprising based on your responses to him that others have been less than keen to jump in.

Anyway that said NetPro is about giving help

1) You are not using vrf's. This line seems to be a standard line IOS puts into your config. If you were using vrf's it may be relevant.

2) Yes, why wouldn't they. I can't see a reason with the config you have supplied why they wouldn't.

3) No although "sh run | begin ip dhcp excluded" would get you to the bit you are interested in.

Jon

wesley.roberts Thu, 10/23/2008 - 16:16

Thank you guys for your help. Greatly appreciated. I have took note of the fact that this is not a site where people get paid & I am sorry that I come accross overbearing.

Kind Regards

Actions

This Discussion