Mariano Absatz wrote:
Hi,
I just discovered that I got wrong what "dhcp-ignore" does... I'll try
to explain what I want and what I did and see if someone can explain me
what I got wrong or, better yet, a way to do what I want :-)
I'm using 2.45 (but can upgrade to 2.46 if needed).
I'm using dnsmasq in a firewall with three "internal" legs (2 different
wifi networks and a local wired net).
In the local wired net I'm using one class "C" network, but I have 2
different ranges (with different treatment in my firewall). I want to
give IP addresses in one range only to MACs I know, and in the other
range to others, so I wrote part of my configuration as in the file
attached... in particular:
dhcp-range=tagIKnowYou,192.168.1.101,192.168.1.120,4h
dhcp-ignore=tagIKnowYou,#known
This means, ignore the host if tagIKnowYou is set AND tag known is NOT
set. Since either both of the tags will be set, or neither, then the
condition is never met.
dhcp-range=tagAllTheRest,192.168.1.161,192.168.1.174,4h
dhcp-host=00:22:33:44:55:66,192.168.1.101,net:tagIKnowYou,mycompany-PC-01
dhcp-host=00:22:33:44:55:02,192.168.1.101,net:tagIKnowYou,mycompany-PC-02
dhcp-host=00:22:33:44:55:03,192.168.1.101,net:tagIKnowYou,mycompany-PC-03
At first everything went the way I wanted... my three known PCs got
their addresses from the first range (192.168.1.101, 192.168.1.102 and
192.168.1.103) and all the rest got address from the second range...
But when we hook up a new computer and I didn't notice that my second
range was too little, instead of rejecting the DHCPREQUEST for not
having enough IPs, it gave it an IP from the first range (192.168.1.104).
I thought that the line:
dhcp-ignore=tagIKnowYou,#known
would prevent this, but clearly I'm understanding it wrong... or I hit a
bug?
Theres no bug, I think.
How should I configure my dnsmasq to prevent unknown MACs from getting
an IP in the "tagIKnowYou" range?
You don't need to set your own tags at all, just use the "known" tag,
which will be set whenever a dhcp-host matches the MAC address.
Then do
dhcp-range=net:known,192.168.1.101,192.168.1.120,4h
dhcp-range=net:#known,192.168.1.161,192.168.1.174,4h
That way, 192.168.1.101... will only be used when the MAC address is
known, and 192.168.1.161... will only be used when the MAC address is
not known.
It's important to understand the two uses of tags in dhcp-range
dhcp-range=<tag>,......
will _set_ the tag if that range is used.
dhcp-range=net:tag,.......
will _use_ the range if the tag is set.
HTH
Simon.
