Posted on 2004-08-30
Medium Priority
Last Modified: 2010-04-11
Hi. I created new a few new Vlans. I now want to have the clients get their IP address from a DHCP server that is on a diferent vlan. But they are not getting the address. I know the DHCP server is set up correctly so I must be missing some thing in the Vlan config

Any ideas??

Question by:kdog3445
  • 3
  • 2
LVL 43

Expert Comment

ID: 11934881
You need to add a helper address for you DHCP server to the VLAN interfaces:

interface vlan2
ip address
ip helper-address    <---use the IP address of the DHCP server.

interface vlan3
ip address
ip helper-address

interface vlan4
ip address
ip helper-address
LVL 15

Expert Comment

ID: 11934907
Hi kdog3445,

VLANs completely seperate the networks, and will limit the broadcast domain for all the devices.
This means that your DHCP server doesn't see the broadcast IP request from the clients on the other VLAN.

To make this work, you'll need to do something to allow the DHCP server to "see" the clients on the other LAN.  Obvious options are:
1 - Install another network card in the server, and plug it into the other VLAN
2 - Use a router of some description to route the traffic between the VLANs

Does that make sense?


Author Comment

ID: 11934950
I tryed that. Does any thing look wrong here

interface Vlan140
 description 4thFloorWorkstation
 ip address
 ip helper-address
 no ip redirects
 standby 100 ip
 standby 100 priority 100
Become a Leader in Data Analytics

Gain the power to turn raw data into better business decisions and outcomes in your industry. Transform your career future by earning your MS in Data Analytics. WGU’s MSDA program curriculum features IT certifications from Oracle and SAS.  

LVL 43

Accepted Solution

JFrederick29 earned 2000 total points
ID: 11935003
You have a scope on your DHCP server for the subnet, right?

Author Comment

ID: 11935067
it is /24 on the DHCP server which I am changing now, Be right back

Author Comment

ID: 11935224
Thanks JFrederick29  I had 2 diferent sub net masks

Featured Post

We Need Your Input!

WatchGuard is currently running a beta program for our new macOS Host Sensor for our Threat Detection and Response service. We're looking for more macOS users to help provide insight and feedback to help us make the product even better. Please sign up for our beta program today!

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

How to fix a SonicWall Gateway Anti-Virus firewall blocking automatic updates to apps like Windows, Adobe, Symantec, etc.
If you try to migrate from Elastix to Issabel, you will face a lot of issues. These problems are inevitable but fortunately, you can fix them. In the guide below, I will explain how I performed the migration while keeping all data and successfully t…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
There's a multitude of different network monitoring solutions out there, and you're probably wondering what makes NetCrunch so special. It's completely agentless, but does let you create an agent, if you desire. It offers powerful scalability …

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question