[Dnsmasq-discuss] dhcp-options ignored for tag

[Simon Kelley]

On 07/02/12 16:37, John Hanks wrote:
> Hi,
> 
> I'm trying to get dnsmasq to return multiple DNS server entries for
> one of our vlans using tags and am not having much success. Variations
> of dhcp-range I've tried are:
> 
> dhcp-range=set:vlan2210,10.210.254.1,10.210.254.255,255.255.0.0,1d
> dhcp-range=vlan2210,10.210.254.1,10.210.254.255,255.255.0.0,1d
> dhcp-range=net:vlan2210,10.210.254.1,10.210.254.255,255.255.0.0,1d
> dhcp-range=tag:vlan2210,10.210.254.1,10.210.254.255,255.255.0.0,1d
> 

The first of these is the one to go for, but you are seeing the correct
tags set.

> Then, the options for that tag are:
> 
> dhcp-option=tag:vlan2210,3
Don't know why this isn't working: it would be useful to see the
complete configuration here.

> dhcp-option=tag:vlan2210,15,"specialdomain.colorado.edu"

OK, this is a special case: because the domain name/hostname is used for
other stuff (like adding to the DNS) it's not possible to just send
option 15, you need to configure dnsmasq's idea of what the domain name
is. For slightly tragic reasons, you can't use the tag system at all to
control this, but you _can_ do it on a subnet basis.

Replacing this option with

domain="specialdomain.colorado.edu",10.210.0.0/16

should do the trick.

> dhcp-option=tag:vlan2210,6,10.210.32.1,10.210.32.2
Again, not sure, it looks like a quirk/bug in selecting tagged options
and seeing the whole config would really help.

> dhcp-option=tag:vlan2210,66,10.210.32.1

"bootfile name: pxelinux.0" in the logs implies that there's a dhcp-boot
configuration somewhere. Either set the servername there (and it's a
name, not an IP address) or remove the dhcp-boot and send the filename
as option 67. Don't mix them.

Cheers,

Simon.