[Last Call] Learn how to a build a cloud-first strategyRegister Now

x
?
Solved

Vlans---DHCP

Posted on 2004-08-30
6
Medium Priority
?
719 Views
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??

Thanks
0
Comment
Question by:kdog3445
  • 3
  • 2
6 Comments
 
LVL 43

Expert Comment

by:JFrederick29
ID: 11934881
You need to add a helper address for you DHCP server to the VLAN interfaces:

interface vlan2
ip address 192.168.1.1 255.255.255.0
ip helper-address 192.168.0.10    <---use the IP address of the DHCP server.

interface vlan3
ip address 192.168.2.1 255.255.255.0
ip helper-address 192.168.0.10

interface vlan4
ip address 192.168.3.1 255.255.255.0
ip helper-address 192.168.0.10
0
 
LVL 15

Expert Comment

by:scampgb
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?

0
 

Author Comment

by:kdog3445
ID: 11934950
I tryed that. Does any thing look wrong here

interface Vlan140
 description 4thFloorWorkstation
 ip address 10.100.40.2 255.255.254.0
 ip helper-address 10.10.1.30
 no ip redirects
 standby 100 ip 10.100.40.1
 standby 100 priority 100
0
Get your Conversational Ransomware Defense e‑book

This e-book gives you an insight into the ransomware threat and reviews the fundamentals of top-notch ransomware preparedness and recovery. To help you protect yourself and your organization. The initial infection may be inevitable, so the best protection is to be fully prepared.

 
LVL 43

Accepted Solution

by:
JFrederick29 earned 2000 total points
ID: 11935003
You have a scope on your DHCP server for the 10.100.40.0/23 subnet, right?
0
 

Author Comment

by:kdog3445
ID: 11935067
it is /24 on the DHCP server which I am changing now, Be right back
0
 

Author Comment

by:kdog3445
ID: 11935224
Thanks JFrederick29  I had 2 diferent sub net masks
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you’re involved with your company’s wide area network (WAN), you’ve probably heard about SD-WANs. They’re the “boy wonder” of networking, ostensibly allowing companies to replace expensive MPLS lines with low-cost Internet access. But, are they …
Make the most of your online learning experience.
If you're a developer or IT admin, you’re probably tasked with managing multiple websites, servers, applications, and levels of security on a daily basis. While this can be extremely time consuming, it can also be frustrating when systems aren't wor…
Monitoring a network: why having a policy is the best policy? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the enormous benefits of having a policy-based approach when monitoring medium and large networks. Software utilized in this v…

831 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