DHCP Best Pratices?

 Originally Posted by mhaase 

The error indicates your clients do not receive the DHCP Option Tags from the WSM DHCP Proxy server.
Check that the DHCP Proxy Service is running and the devices are present in the WSM console.
If the clients are in a different IP subnet than the WSM Server, you must configure port-forwarding on the routers/switches so the DHCP Broadcast request is forwarded to the WSM Server.
You will not find anything in the client logfiles as this are populated only after a client has received the WSM-Bootstrap and start OS streaming. Looking at admin.log is an good idea, as the WSM admin service controls the DHCP proxy.

Thanks for the suggestions and I am looking at the admin.log now; although, I don't know exactly what I'm looking for. I have been struggling with this for a month now and have created a support ticket with WYSE. After switching out all of our network hardware (firewall, switches, etc...), I'm still seeing 7 or 8 devices not get a DHCP IP address out of only 27 devices. I don't get it! It's not like we have 5,000 devices with WSM core and edge servers. It's a really simple setup and it has worked flawlessly for over 2 years.

Search the admin.log for [Error]
You are using Z-Class hardware, correct?
Is the DHCP Proxy service configured for enable device discovery or not?
Are the failing devices listed in the WSM Console?
Is the WSM database on the WSM Server or remote?
What WSM version are you using?
One or more WSM Server?
Are the devices not working random or is there a pattern?
Is this only happening when you boot all clients at the same time, or also when clients boot after each other?
Does the DHCP Server show any error or can you make sure there is no problem with the DHCP scope, lease time and # of available IP-Addresses?
What was changed so it was working two years but fails now?
Have you tried disabling spanning tree or portfast on your routers if these settings are in place?

There is no need for any special DHCP configuration or using static IPs.
You can use whatever DHCP Server you want.
All you need to ensure is that the WSM server receives the DHCP request from a client booting, so it can issue the DHCP options 66 & 67 to tell the client where to load the WSM bootstrap from.

Strange, indeed. I do not think this is a WSM issue as it would have been reported to us as WSM 4.0.1 is out for a while now.
If all devices are present in the WSM UI the WSM DHCP Proxy Service should issue the WSM Bootstrap to them when they do a PXE-Boot, assumed the DHCP-Broadcast can travel from the client network to the WSM Server (keyword: DHCP-Forwarder). 
Regarding the log files: please continue to work with Wyse Post Sales on this issue and provide log files to them on request.

Search the admin.log for [Error]
Searching the admin.log only shows 1 specific error (repeatedly)for a MAC address that is not found is DB. I’ll have to investigate that. Is it possible that some configuration might have automatically changed when I upgraded from WSM 3.6 to 4.0 and then 4.0.1?
You are using Z-Class hardware, correct?
R-Class, my OP is incorrect, sorry
Is the DHCP Proxy service configured for enable device discovery or not?
DHCP proxy is handled by our Linksys firewall and is configured for discovery
Are the failing devices listed in the WSM Console?
All devices are listed in the WSM Console
Is the WSM database on the WSM Server or remote?
WSM database is on the WSM server
What WSM version are you using?
WSM version 4.0.1
One or more WSM Server?
One WSM server
Are the devices not working random or is there a pattern?
It is random
Is this only happening when you boot all clients at the same time, or also when clients boot after each other?
It happens for both scenarios. I have tested the Wake on LAN feature to start all 27 devices at the same time. I have also tested the Wake on LAN feature with 3 separate groups of 9 devices with 10 minute intervals.
Does the DHCP Server show any error or can you make sure there is no problem with the DHCP scope, lease time and # of available IP-Addresses?
The DHCP scope is fine and it allows for 200 IP addresses and the lease time is setup for 10 minutes.
What was changed so it was working two years but fails now?
Nothing has changed which is why I’m miffed at the whole thing. My first thought was hardware failures, but that isn’t the case
Have you tried disabling spanning tree or portfast on your routers if these settings are in place?
No

I've seen other forums where people can post up logs and ask for suggestions. Is that a possibility or is a security risk or something?

The error indicates your clients do not receive the DHCP Option Tags from the WSM DHCP Proxy server.
Check that the DHCP Proxy Service is running and the devices are present in the WSM console.
If the clients are in a different IP subnet than the WSM Server, you must configure port-forwarding on the routers/switches so the DHCP Broadcast request is forwarded to the WSM Server.
You will not find anything in the client logfiles as this are populated only after a client has received the WSM-Bootstrap and start OS streaming. Looking at admin.log is an good idea, as the WSM admin service controls the DHCP proxy.

 Originally Posted by mhaase 

There is no need for any special DHCP configuration or using static IPs.
You can use whatever DHCP Server you want.
All you need to ensure is that the WSM server receives the DHCP request from a client booting, so it can issue the DHCP options 66 & 67 to tell the client where to load the WSM bootstrap from.

Thanks, mhaase. I haven't had any issues sending an IP to my clients, but recently I have seen some strange "No DHCP or proxy DHCP offers received". I was thinking that the connection is timing out or something trying to get an IP from the firewall. Could there be something on the client logs that could verify this?

 Originally Posted by  timothyburger 

I recognize that this post is a bit old now and I wonder if BSquared every was able to resolve the issue? If not I would recommend configuring the "next-server" option and "boot-file-name" on your dhcp server and turning off the proxy dhcp service altogether. We do this for over 200 R Series devices as it works much faster for us and avoids the proxy dhcp issue completely.

The problem still exists and WYSE post sales describe the issue as a network not WYSE/WSM problem. I, unfortunately, can only work on this problem after hours which is making this thread a bit "long in the tooth".
To summarize my issue: I believe that the PXE error is due to the communication between my R00L and Z00L clients timing out while trying to retrieve an IP address. I have updated all the firmware for ALL our network GB switches and have tested connection speeds with my laptop. 
@timothyburger - Since proxy DHCP is handled by our firewall, where exactly do I confirm that it is NOT running on the WSM server?

I recognize that this post is a bit old now and I wonder if BSquared every was able to resolve the issue? If not I would recommend configuring the "next-server" option and "boot-file-name" on your dhcp server and turning off the proxy dhcp service altogether. We do this for over 200 R Series devices as it works much faster for us and avoids the proxy dhcp issue completely.