WDS across subnets question...

[DMartin]

Hi!

 

A quick bit of background info before I ask my question,

 

I'm a new IT guy for a university that currently use MDT for their deployment and they are eager to get WDS PXE Boot off the ground, BUT, they have 2 sites (soon to be 3 sites) within close proximity to each other that have 6 separate IP ranges with a mixture of DHCP and static IP allocation. I have been toying with discovery images for the static IP ranges but I know that each disk will need to have the same IP address as the boot image to be able to communicate which is extra work, I think I already know what the answer might be but I just wanted to put the feelers out there just in case some clever person has managed to get around this problem in the past?

 

So my question is WDS PXE Boot across sub-nets, possible or impossible?

 

Dan

[ThomL]

For this to work wouldn't the server IP have to be accessible on all subnets? or would it be a case of the DHCP server for that subnet broadcasting the address of the server for PXE? ...or the need for multiple NICs on the deployment server accessible on all subnets so that the DHCP of that subnet can broadcast an IP that is accessible.. I don't have a test bench to check any of this, just thinking aloud....

[DMartin]

I believe that would be the case if all of your IP were assigned via DHCP, unfortunately we have static allocation for most machines here. According to MS, WDS PXE will only work on machines that are assigned IP via DHCP, I know its a long shot of there being a alternative solution! If it was up to me I would work at getting DHCP rolled out across the whole site before getting WDS up and running but unfortunately I cannot make that call.

[ThomL]

After a quick google it does seem to be achievable with IP Helpers and/or some DHCP options (60,66,67). Good Luck!

 

-edit- browser just updated with you're last reply, I remember a a contractor we had in a while ago speaking of modifying AD so that Machine account hold info such as the client MAC addresses and using litetouch to fully automate a build:

 

lite touch launches picks up predefined comp name from AD,

then installs OS setting comp name from AD,

then a separate task within the task sequence sets the static IP from a in-house pre-configured script.

 

that way it would run DHCP address through build and then assign static at the end of build or something similar to that? :S

 

-edit 2- would it be a case with litetouch to pick up the MAC address reference that - pick up machine name and then from there pick up ip address then deploy the OS so that these values are applied before joining a domain and not messing up DNS

 

-edit 3 - ..... am I thinking about MDT and not WDS :S I am feeling confused!

Edited December 10, 2013 by ThomL

[DMartin]

Ah that looks like it might be the info I have been looking for thanks ThomL - I shall report back!

[themightymrp]

All you need to do is set the IP helper address for each subnet on your router or layer 3 switch to the IP address of the DHCP server.

 

Then, in your DHCP scopes set option 66 to be the IP address of the WDS server and set option 67 to be boot\x86\wdsnbp.com

[Davit2005]

You may only need the IP helper addresses configured on each individual vLan as per @ThomL . You may not need the options unless your PXE server is on the DHCP server I think but please check that out.

[themightymrp]

You should still need to set option 66 and 67 to enable booting to PXE. Option 60 is the optional one if WDS and DHCP are running on the same server. Mine are separate so I don't set option 60.

[ThomL]

But to handle the static IP/DHCP/comp. name stuff you might have to look at some sort of lite touch/unattend.xml/scripts/task sequences we run WDS+MDT here and I think the things you want are achievable

[themightymrp]

Not sure about the MAC address in AD part as we don't go that fine tuned, but you can use an SQL database with MDT (we use MDT on top of WDS) to define your machines and assign specific task sequences and settings based on that...

[ThomL]

Not sure about the MAC address in AD part as we don't go that fine tuned, but you can use an SQL database with MDT (we use MDT on top of WDS) to define your machines and assign specific task sequences and settings based on that...

 

This setup with the last tasks to be setting IP and joining the domain would work?

 

The MAC address integration is something I've just been told about and not really looked into - with your setup do you need to input the Machine name at the begging of the build so MDT/WDS can assign a task from that point?

 

If thats the case and OP doesn't need a fully automatic deployment system this sound like the solution to me - a task executing a .ps or .vbs from a central location to change network adapter setting based on machine name at the end of the build. Then modify/maintain script as things progress? or is there a better way to do this as well?

[DMartin]

All working now!

 

I made such a stupid newb mistake - i'm currently only running one nic in this server while i'm testing the theory. My I.P. info was set to network (A) but the port I was testing with was configured for network (B) even though its labeled as (A) I was unaware as our networking is managed at another site. So it was working the whole time across sub-nets!

 

Thank you for all the replies!