dhcp-relay is intended as a replacement for ISC dhcrelay and
specifically it's
OpenBSD descendant.
The motivation for this was the lack of support in dhcrelay for
interfaces on multiple IP subnets. dhcrelay assumed a single
primary address on an interface and would only relay DHCP requests
as that one DHCP gateway. dhcp-relay is designed to support this,
but also aims to be a better implementation of this part of the
DHCP protocol.
usage: dhcp-relay [-vd] [-C circuit] [-R remote] [-H hoplim] -i interface
destination ...
dhcp-relaysupports acting as a DHCP gateway for all the IP subnets configured on the specified interface, not just the first network.- The BPF filter used on the interface is restricted to accepting broadcast and multicast Ethernet packets, what the RFC calls "locally delivered datagrams". This stops the relay intercepting unicast packets, eg, DHCP INFORM packets from clients sent directly to their server, or packets from other DHCP relays.
- The ability to list extra "helper" servers that can send messages via the relay to the client network, but are not sent client requests.
- Support for operating on enc(4) interfaces
- Add all missing
dhcrelayfeatures - Support use in a DHCP relay chain
- Get this into OpenBSD so I can stop using git