Netinstall/Netboot across subnets

[Sheridan]

I'm deploying 10.9 across our Mac suite, and using Deploystudio for the image deployment and Netinstall on the osx server to boot the macs. This only works if the macs are on the same subnet as the server - which they aren't anymore as they are now in a seperate physical location from when I did the original deployment years ago.

 

I've read about this and setting DHCP helpers etc - but this all works across our routed subnets anyway (no vlans - just subnets routed on a L3 switch)

 

Is there any way to configure netinstall to respond to requests on seperate subnets?

[FN-GM]

How do you mean you have no VLAN but have separate subnets? How are your subnets separated then?

 

What switches do you have?

 

This needs to go into the wired networking forum really.

[Sheridan]

They're just basic netgear switches - the core switch is where all the fibre channels meet. Each fibre port is an IP subnet (defined by physical location) - the other end of the fibre is a set of stacked smart switches.

 

Everything works across the subnets as it all routed, apart from netboot. I've tried the 'bless' command but I've not had much luck with it!

[Norphy]

How are you managing DHCP across your subnets? Presumably you have some kind of relay or helper object in place on your router? You need the same thing for your Netboot server too.

[FN-GM]

How do you get your DHCP across from one subnet to your servers subnet? You just need to do the same for the NetBoot server.

[Sheridan]

DHCP is working through using a IP Helper setting on the core switch - but as this is a fairly basic switch it only allows configuration of the single DHCP server address, along with a backup address - not a list of addresses.

 

So I can't add the DS server address in there, but the mac clients are getting dhcp addresses. I've tried every variation of the bless command but it doesn't seem to have any effect at all!

[FN-GM]

In that case you will need to make some big changes to get it work.

 

1. Change your core switch.

2. Reconfigure it some way (possibly into vlans) - If this is possible at all. I am not up with Netgear.

3. Have a router to do your routing between the VLANS and not the core switch. Have you IP helper set on this router.

4. Make the boot server the DHCP server also.

 

The issue is happening because your Clients can't find the boot server, this is due to a lack of helper address.

Edited August 19, 2014 by FN-GM

[Dos_Box]

Moving to Wired Networks forum.

[Sheridan]

Hmm looks like option '5) Bring the macs back to the main server room' is going to be the best short term option!

[Norphy]

DHCP is working through using a IP Helper setting on the core switch - but as this is a fairly basic switch it only allows configuration of the single DHCP server address, along with a backup address - not a list of addresses.

 

So I can't add the DS server address in there, but the mac clients are getting dhcp addresses. I've tried every variation of the bless command but it doesn't seem to have any effect at all!

 

The bless command isn't going to do you any good whatsoever.

 

The way the Macs find the Netboot server is similar to how a computers gets a DHCP address. FWIW, PXE works in a similar manner too. The Mac sends a broadcast out to the network saying "Is there a netboot server here?". Broadcasts can't traverse subnets without help so the broadcast isn't received by the Netboot server. The way that you get around this is to put an IP Helper on the router which says "Direct all broadcasts to this IP address". Pretty much your only option is to do as FN-GM says or to put the Netboot server into the same subnet as your Macs.

[FN-GM]

or to put the Netboot server into the same subnet as your Macs.

 

Didn't think of that! ha ha

[Sheridan]

It looks like the limitations of our our l3 switch are the issue then - I can only add a single ip helper address (with a backup address) and not an actual list of them like you can on cisco kit.

[FN-GM]

It looks like the limitations of our our l3 switch are the issue then - I can only add a single ip helper address (with a backup address) and not an actual list of them like you can on cisco kit.

 

Yep. I would look at replacing it. You can get pretty affordable L3 Cisco and HP switches.

 

You could even buy Something like a cheap Cisco 3560 from eBay and just use it for this subnet. But it would start to get a little more complex.

Edited August 19, 2014 by FN-GM

[Sheridan]

Ah ha! I seem to have it working. Our switch does have a well hidden option to add udp relay lists (the dhcp helper is a separate option) - I've added the subnet/server addresses for ports 67,68 and 69 and we now have netbooting macs on the separate subnet!

 

Entering these did cause the router to lockup and bring the entire network down for 5 minutes until I rebooted it but it might get me around the current problem

[FN-GM]

Great news!

 

Sorry i wasn't much help I haven't use NetGear beyond home routers.

[Sheridan]

Great news!

 

Sorry i wasn't much help I haven't use NetGear beyond home routers.

 

Far from it - you (and Norphy) pointed me in the right direction, it was definitely a routing issue.

 

All I need now is some spare budget to replace our old but reliable net gear kit!

[Norphy]

Nicely done!