Hi folks,
I'm confused about another thing too.
I have an external backup drive, connected via a network cable. When things boot up, it gets IP addresses for its drives from my dhcp server.
This used to work fine. Recently however, I find that the drive's complaining of a "DHCP network addressing problem" (according to the blinking light code!). If, before the drive boots I disable my UFW firewall with sudo ufw disable, then boot the drive, then enable the firewall, everything's OK. If I don't disable the firewall while the drive's getting an IP address, I get the error.
I'm running dnsmasq as a dhcp server.
My ufw rules are like this
$ sudo ufw status Status: active
To Action From -- ------ ---- 67 ALLOW 169.254.0.0/16 68 ALLOW 169.254.0.0/16 67 ALLOW 0.0.0.0 68 ALLOW 0.0.0.0 192.168.55.66 ALLOW 192.168.55.0/24
I've omitted 4 rules which open up specific ports, with a format like this as they're not relevant (at least I think they're not relevant) 192.168.55.66 123 ALLOW Anywhere 192.168.55.66 456/tcp ALLOW Anywhere
As I understand it, the ports I need to allow access to are 67 and 68. When something asks for an IP address and it hasn't already got one, it broadcasts from the broadcast address 0.0.0.0. Sometimes, a machine will assign itself an IP address in the 169.254.0.0/16 range - e.g. a Windows machine that can't find a DHCP server on the network. If I allow this range then such machines can contact the DHCP server. The final line should allow anything with an address in the range 192.168.55.0 - 192.168.55.255 to contact any port on my server 192.168.55.66, which is where the DHCP server is.
It seems to me I must have something wrong with the UFW rules, otherwise why would disabling it allow the drive to get a DCHP lease? What have I got wrong?
Any ideas appreciated. Cheers Steve