README

   1 odhcpd - Embedded DHCP/DHCPv6/RA Server & Relay
   2
   3 ** Abstract **
   4
   5 odhcpd is a daemon for serving and relaying IP management protocols to
   6 configure clients and downstream routers. It tries to follow the RFC 6204
   7 requirements for IPv6 home routers.
   8
   9 odhcpd provides server services for DHCP, RA, stateless and stateful DHCPv6,
  10 prefix delegation and can be used to relay RA, DHCPv6 and NDP between routed
  11 (non-bridged) interfaces in case no delegated prefixes are available.
  12
  13
  14 ** Features **
  15
  16 1. Router Discovery support (solicitations and advertisements) with 2 modes
  17    server:      RD server for slave interfaces
  18    a) automatic detection of prefixes, delegated prefix and default routes, MTU
  19    b) automatic reannouncement when changes to prefixes or routes occur
  20
  21    relay:       RD relay between master and slave interfaces
  22    a) support for rewriting announced DNS-server addresses in relay mode
  23
  24 2. DHCPv6-support with 2 modes of operation
  25    server: stateless, stateful and PD-server mode
  26    a) stateless and stateful address assignment
  27    b) prefix delegation support
  28    c) dynamic reconfiguration in case prefixes change
  29    d) hostname detection and hosts-file creation
  30
  31    relay:       mostly standards-compliant DHCPv6-relay
  32    a) support for rewriting announced DNS-server addresses
  33
  34 3. DHCPv4-support
  35    server: stateless and stateful mode
  36
  37 4. Proxy for Neighbor Discovery messages (solicitations and advertisements)
  38    a) support for auto-learning routes to the local routing table
  39    b) support for marking interfaces "external" not proxying NDP for them
  40       and only serving NDP for DAD and for traffic to the router itself
  41       [Warning: you should provide additional firewall rules for security]
  42
  43
  44 ** Compiling **
  45
  46 odhcpd uses cmake:
  47 * To prepare a Makefile use:  "cmake ."
  48 * To build / install use: "make" / "make install" afterwards.
  49 * To build DEB or RPM packages use: "make package" afterwards.
  50
  51
  52 ** Configuration **
  53
  54 odhcpd uses a UCI configuration file in /etc/config/dhcp for configuration
  55 and may also receive information from ubus
  56
  57
  58 Section of type odhcpd
  59
  60 Option          Type    Default                 Description
  61 legacy          bool    0                       Enable DHCPv4 if start but
  62                                                 no dhcpv4 option set
  63 maindhcp        bool    0                       Use odhcpd as the main DHCPv4
  64                                                 service
  65 leasefile       string                          DHCP/v6 lease/hostfile
  66 leasetrigger    string                          Lease trigger script
  67 loglevel        integer 6                       Syslog level priority (0-7)
  68
  69
  70 Sections of type dhcp (configure DHCP / DHCPv6 / RA / NDP service)
  71
  72 Option          Type    Default                 Description
  73 interface       string  <name of UCI section>   logical OpenWrt interface
  74 ifname          string  <resolved from logical> physical network interface
  75 networkid       string  same as ifname          compat. alias for ifname
  76 ignore          bool    0                       do not serve this interface
  77                                                 unless overridden by ra, ndp,
  78                                                 dhcpv4 or dhcpv6 options
  79 master          bool    0                       is a master interface
  80                                                 for relaying
  81
  82 ra              string  disabled                Router Advert service
  83                 [disabled|server|relay|hybrid]
  84 dhcpv6          string  disabled                DHCPv6 service
  85                 [disabled|server|relay|hybrid]
  86 dhcpv4          string  disabled                DHCPv4 service
  87                 [disabled|server]
  88 ndp             string  disabled                Neighbor Discovery Proxy
  89                 [disabled|relay|hybrid]
  90
  91 dynamicdhcp     bool    1                       dynamically create leases
  92                                                 for DHCPv4 and DHCPv6
  93 router          list    <local address>         Routers to announce
  94                                                 accepts IPv4 only
  95 dns             list    <local address>         DNS servers to announce
  96                                                 accepts IPv4 and IPv6
  97 domain          list    <local search domain>   Search domains to announce
  98
  99 leasetime       string  12h                     DHCPv4 address leasetime
 100 start           integer 100                     DHCPv4 pool start
 101 limit           integer 150                     DHCPv4 pool size
 102
 103 ra_default      integer 0                       Override default route
 104                 0: default, 1: ignore no public address, 2: ignore all
 105 ra_management   integer 1                       RA management mode
 106                 0: no M-Flag but A-Flag, 1: both M and A, 2: M but not A
 107 ra_offlink      bool    0                       Announce prefixes off-link
 108 ra_preference   string  medium                  Route(r) preference
 109                 [medium|high|low]
 110 ra_maxinterval  integer 600                     Maximum time allowed between
 111                                                 sending unsolicited RA
 112 ra_mininterval  integer 200                     Minimum time allowed between
 113                                                 sending unsolicited RA
 114 ra_lifetime     integer 1800                    Value to be placed in Router
 115                                                 Lifetime field of RA
 116 ra_useleasetime bool    0                       Use configured leasetime as
 117                                                 limit for the preferred and
 118                                                 valid lifetime of a prefix
 119 ra_mtu          integer 0                       MTU to be advertised in
 120                                                 RA messages
 121 ndproxy_routing bool    1                       Learn routes from NDP
 122 ndproxy_slave   bool    0                       NDProxy external slave
 123
 124
 125 Sections of type host (static leases)
 126 Option          Type    Default                 Description
 127 ip              string                          IP-Address to lease
 128 mac             string                          MAC-address
 129 duid            string                          DUID in base16
 130 hostid          string                          IPv6 host identifier
 131 name            string                          Hostname
 132 leasetime       string                          DHCPv4/v6 leasetime
 133