[Dnsmasq-discuss] Removing a feature does anyone rely on this?

Helmut Hullen Hullen at t-online.de
Mon Jul 2 04:42:00 BST 2012


Hallo, Simon,

Du meintest am 01.07.12:

> A quote from the man page:

> dhcp-range may have an interface name supplied as
> "interface:<interface-
name>> ". The semantics if this are as follows: For  DHCP, if any other
> dhcp-range exists _without_ an interface name, then the interface
> name is  ignored  and  and  dnsmasq behaves  as  if  the interface
> parts did not exist,

[...]

> This feature was added to facilitate integration with uses such as
> libvirt, where libvirt could automatically add extra facilities to a
> single "system" dnsmasq instance. It has never been used as such, and
> things like libvirt and openstack and networkmanager have instead
> gone down the route of running their own "private" dnsmasq instances.

I'd like to use this feature in many schools:

eth0 and eth1 for the school clients in the LAN, eth2 for the private  
clients (especially in the WLAN). And eth3 for DSL/Router into the WAN.

Other services (like squid) may allow or disallow something depending on  
the net range (and therefore on the NIC).

The major problem: sometimes a NIC dies and has to be replaced, and then  
the NIC names may change too. Other services (especially samba and  
squid) allow something like "interfaces=eth0 eth1 local", and that is  
simple to change by a script which first detects which interfaces serve  
which net. But it seems to be a bit more difficult to change  
automatically something like

    dhcp-range=eth0,192.168.0.10,static
    dhcp-range=eth1,192.168.1,10,static
    dhcp-range=eth2,192.168.17.10-192.168,28.250

to

    dhcp-range=eth0,192.168.0.10,static
    dhcp-range=eth2,192.168.1,10,static
    dhcp-range=eth1,192.168.17.10-192.168,28.250

when the names of eth1 and eth2 have changed.

It's a problem which happens seldom, and when it happens the system  
administrator has forgotten that he has to check these entries too.

> But if there is anyone
> using it for other than it's intended use, that's going to cause them
> problems. The best I can do to find out if this is used is to ask on
> the list. Not perfect, but if no-one here is using it, that's a
> reasonable indication that it's un-used.

I'd be happy if there is a simple (scriptable) solution.

Viele Gruesse!
Helmut



More information about the Dnsmasq-discuss mailing list