Learn how to a build a cloud-first strategyRegister Now


Sonicwall TZ170 firewall not handing out DHCP leases

Posted on 2006-04-05
Medium Priority
Last Modified: 2008-02-01
We are setting up a new office.  We have a T1 connected to a Cisco 2811 router then to a Sonicwall Tz170 firewall with enhanced OS.  The firewall, connectivity, etc all work fine.  The DHCP server is enabled (not passthrough) and a lease range of has been added w/ a subnet mask of  (we are using a class B for organizational purposes, not for sheer # of nodes).

When the PCs are set to static IPs in this range or any other, they work fine - LAN / internet access, etc all OK.  I can even get to the web management console on the FW.  But when set to DHCP, they are not able to aquire an IP address.  

I've contacted Sonicwall support but have not heard back yet.  Help!

Question by:cef_soothsayer

Expert Comment

ID: 16381980
Do you have the DHCP set up on the right interface?  You can set up (or not) on both the lan and the opt interface.

Expert Comment

ID: 16383313
run an ipconfig/all and see if you have another computer acting as a dhcp server handing out bad ip ranges

Author Comment

ID: 16412489
FIXED - The problem was not the firewall at all.  The Cisco Catalyst Express 500 24TT swithc that it was plugged into was blocking DHCP relay request broadcasts.  This switch has "port roles" assigned to it and the role needed to be switched to "other".  The settings for "PC" or "Server" on this port were not working.

Accepted Solution

GranMod earned 0 total points
ID: 16791667
PAQed with points refunded (250)

Community Support Moderator

Featured Post

Prepare for your VMware VCP6-DCV exam.

Josh Coen and Jason Langer have prepared the latest edition of VCP study guide. Both authors have been working in the IT field for more than a decade, and both hold VMware certifications. This 163-page guide covers all 10 of the exam blueprint sections.

Question has a verified solution.

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

During and after that shift to cloud, one area that still poses a struggle for many organizations is what to do with their department file shares.
In this article, WatchGuard's Director of Security Strategy and Research Teri Radichel, takes a look at insider threats, the risk they can pose to your organization, and the best ways to defend against them.
Viewers will learn how to connect to a wireless network using the network security key. They will also learn how to access the IP address and DNS server for connections that must be done manually. After setting up a router, find the network security…
NetCrunch network monitor is a highly extensive platform for network monitoring and alert generation. In this video you'll see a live demo of NetCrunch with most notable features explained in a walk-through manner. You'll also get to know the philos…

810 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