Hi all, I've been trying to solve the same problem described in this blog post: https://blog.fhrnet.eu/2020/03/07/dhcp-server-on-a-32-subnet/
In a nutshell, the situation is a VM host which performs routing and firewalling for all its guests, providing an isolated IPv4 /32 (and in my case an IPv6 /64 or /128 as well) to each VM guest, and using interface routes on the host to direct traffic to each guest, without wasting IPv4 addresses on /31 or /30 point-to-point links. The post claims that the configuration noted (a single /32 allocated to the host which is configured on every client-facing interface) is only possible at present with ISC DHCP. I've tested a number of different configurations of dnsmasq, and this seems to be correct. I'm hoping someone experienced in the dnsmasq code base can confirm or deny this. Assuming this is currently a limitation, I'd like to work on adding support to dnsmasq for this scenario. I'm not experienced with the code base (although I've read some of the relevant portions and believe it should be possible), so I'm hoping also for some guidance on whether this functionality would be accepted into the code base, and if so, how it might appear in the configuration. My initial thought was that there wouldn't need to be any explicit configuration; rather, if a DHCP request is received on an interface with a /32 mask (or perhaps on an interface with a non-unique address on the host), the usual restrictions around interface matching would be relaxed, and an address would be given out either from the statically-defined hosts, or from a pool which doesn't match any interface on the host. When giving out IPv6 addresses, my thought was that things would mostly work the same if a DHCPv6 request was received on an interface with only link-local addressing configured. Thanks in advance - I hope all this makes sense and look forward to discussing it further with you. Regards, Paul _______________________________________________ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
