odhcpd - Embedded DHCP/DHCPv6/RA Server & Relay
** Abstract **
odhcpd is a daemon for serving and relaying IP management protocols to
configure clients and downstream routers. It tries to follow the RFC 6204
requirements for IPv6 home routers.
odhcpd provides server services for DHCP, RA, stateless and stateful DHCPv6,
prefix delegation and can be used to relay RA, DHCPv6 and NDP between routed
(non-bridged) interfaces in case no delegated prefixes are available.
** Features **
1. Router Discovery support (solicitations and advertisements) with 2 modes
server:	RD server for slave interfaces
a) automatic detection of prefixes, delegated prefix and default routes, MTU
b) automatic reannouncement when changes to prefixes or routes occur
relay:	RD relay between master and slave interfaces
a) support for rewriting announced DNS-server addresses in relay mode
2. DHCPv6-support with 2 modes of operation
server: stateless, stateful and PD-server mode
a) stateless and stateful address assignment
b) prefix delegation support
c) dynamic reconfiguration in case prefixes change
d) hostname detection and hosts-file creation
relay: mostly standards-compliant DHCPv6-relay
a) support for rewriting announced DNS-server addresses
3. DHCPv4-support
server: stateless and stateful mode
4. Proxy for Neighbor Discovery messages (solicitations and advertisments)
a) support for auto-learning routes to the local routing table
b) support for marking interfaces "external" not proxying NDP for them
and only serving NDP for DAD and for traffic to the router itself
[Warning: you should provide additional firewall rules for security]
** Compiling **
odhcpd uses cmake:
* To prepare a Makefile use: "cmake ." * To build / install use: "make" / "make install" afterwards.
* To build DEB or RPM packages use: "make package" afterwards.
** Configuration **
odhcpd uses a UCI configuration file in /etc/config/dhcp for configuration
and may also receive information from ubus
Section of type odhcpd
Option Type	Default Description
legacy bool	0 Enable DHCPv4 if start but
no dhcpv4 option set
leasefile	string DHCP/v6 lease/hostfile
leasetrigger	string Lease trigger script
Sections of type dhcp (configure DHCP / DHCPv6 / RA / NDP service)
Option Type	Default Description
interface	string	<name of UCI section>	logical OpenWrt interface
ifname string	<resolved from logical>	physical network interface
networkid	string	same as ifname compat. alias for ifname
ignore bool	0 ignore this interface
master bool	0 is a master interface
for relaying
ra string	disabled Router Advert service
[disabled|server|relay|hybrid]
dhcpv6 string	disabled DHCPv6 service
[disabled|server|relay|hybrid]
dhcpv4 string	disabled DHCPv4 service
[disabled|server]
ndp string	disabled Neighbor Discovery Proxy
[disabled|relay|hybrid]
dynamicdhcp	bool	1 dynamically create leases
for DHCPv4 and DHCPv6
router list <local address> Routers to announce
accepts IPv4 only
dns list	<local address> DNS servers to announce
accepts IPv4 and IPv6
domain list	<local search domain>	Search domains to announce
leasetime	string	12h DHCPv4 address leasetime
start integer	100 DHCPv4 pool start
limit integer	150 DHCPv4 pool size
ra_default	integer	0 Override default route
0: default, 1: ignore no public address, 2: ignore all
ra_management	integer	1 RA management mode
0: no M-Flag but A-Flag, 1: both M and A, 2: M but not A
ra_offlink	bool	0 Announce prefixes off-link
ra_preference	string	medium Route(r) preference
[medium|high|low]
ndproxy_routing	bool	1 Learn routes from NDP
ndproxy_slave	bool	0 NDProxy external slave
Sections of type host (static leases)
Option Type	Default Description
ip string IP-Address to lease
mac string MAC-address
duid string DUID in base16
hostid string IPv6 host identifier
name string Hostname