IMHO this is an important bug because it randomly interferes with other applications - lots of which use defined ports above 1024.
My recent case caused an OpenVPN instance to fail to start. More seriously it created a security risk since the port in question was of course open on the firewall for purposes of the VPN, and an outsider could have used it to fire data at dhcpd with who knows what results. There is the same issue with isc-dhcp-client; per https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1176046 it seems the folks at ISC are unwilling to respect the defined dynamic port range, and they should be persuaded. Rather than allowing the kernel to assign a random port number like most applications, they want to do it "by self". The solution for that bug was to split isc-dhcp-client into two versions, one compiled with and one without ddns support. That could also be done with dhcpd, however, in my opinion it's an ugly solution. If we are going to have to just live with random ports starting from 1024, it would make a LOT more sense to alter the effect of ddns-update- style none (and ddns-updates off) so that dhcpd does NOT bind to random ports when those config parameters dictate that the random ports are never going to be used anyway. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1670303 Title: dhcpd does not respect ip_local_port _range or ip_local_reserved_ports To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1670303/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
