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32 .Nd Protocol Independent Multicast
35 .Cd "options MROUTING"
40 .In netinet/ip_mroute.h
43 .Fn getsockopt "int s" IPPROTO_IP MRT_PIM "void *optval" "socklen_t *optlen"
45 .Fn setsockopt "int s" IPPROTO_IP MRT_PIM "const void *optval" "socklen_t optlen"
47 .Fn getsockopt "int s" IPPROTO_IPV6 MRT6_PIM "void *optval" "socklen_t *optlen"
49 .Fn setsockopt "int s" IPPROTO_IPV6 MRT6_PIM "const void *optval" "socklen_t optlen"
52 is the common name for two multicast routing protocols:
53 Protocol Independent Multicast - Sparse Mode (PIM-SM) and
54 Protocol Independent Multicast - Dense Mode (PIM-DM).
56 PIM-SM is a multicast routing protocol that can use the underlying
57 unicast routing information base or a separate multicast-capable
58 routing information base.
59 It builds unidirectional shared trees rooted at a Rendezvous
61 and optionally creates shortest-path trees per source.
63 PIM-DM is a multicast routing protocol that uses the underlying
64 unicast routing information base to flood multicast datagrams
65 to all multicast routers.
66 Prune messages are used to prevent future datagrams from propagating
67 to routers with no group membership information.
69 Both PIM-SM and PIM-DM are fairly complex protocols,
70 though PIM-SM is much more complex.
71 To enable PIM-SM or PIM-DM multicast routing in a router,
72 the user must enable multicast routing and PIM processing in the kernel
75 about the kernel configuration options),
76 and must run a PIM-SM or PIM-DM capable user-level process.
77 From developer's point of view,
78 the programming guide described in the
79 .Sx "Programming Guide"
80 section should be used to control the PIM processing in the kernel.
83 After a multicast routing socket is open and multicast forwarding
84 is enabled in the kernel
87 one of the following socket options should be used to enable or disable
88 PIM processing in the kernel.
89 Note that those options require certain privilege
90 (i.e., root privilege):
93 int v = 1; /* 1 to enable, or 0 to disable */
94 setsockopt(mrouter_s4, IPPROTO_IP, MRT_PIM, (void *)&v, sizeof(v));
98 int v = 1; /* 1 to enable, or 0 to disable */
99 setsockopt(mrouter_s6, IPPROTO_IPV6, MRT6_PIM, (void *)&v, sizeof(v));
102 After PIM processing is enabled, the multicast-capable interfaces
106 In case of PIM-SM, the PIM-Register virtual interface must be added
108 This can be accomplished by using the following options:
112 memset(&vc, 0, sizeof(vc));
113 /* Assign all vifctl fields as appropriate */
115 if (is_pim_register_vif)
116 vc.vifc_flags |= VIFF_REGISTER;
117 setsockopt(mrouter_s4, IPPROTO_IP, MRT_ADD_VIF, (void *)&vc,
123 memset(&mc, 0, sizeof(mc));
124 /* Assign all mif6ctl fields as appropriate */
126 if (is_pim_register_vif)
127 mc.mif6c_flags |= MIFF_REGISTER;
128 setsockopt(mrouter_s6, IPPROTO_IPV6, MRT6_ADD_MIF, (void *)&mc,
132 Sending or receiving of PIM packets can be accomplished by
137 with protocol value of
142 pim_s4 = socket(AF_INET, SOCK_RAW, IPPROTO_PIM);
147 pim_s6 = socket(AF_INET6, SOCK_RAW, IPPROTO_PIM);
150 Then, the following system calls can be used to send or receive PIM
171 .\" XXX the PIM-SM number must be updated after RFC 2362 is
172 .\" replaced by a new RFC by the end of year 2003 or so.
173 The PIM-SM protocol is specified in RFC 2362 (to be replaced by
174 .%T draft-ietf-pim-sm-v2-new-* ) .
175 The PIM-DM protocol is specified in
176 .%T draft-ietf-pim-dm-new-v2-* ) .
180 The original IPv4 PIM kernel support for IRIX and SunOS-4.x was
184 Later the code was ported to various
186 flavors and modified by
187 .An George Edmond Eddy
191 .An Pavlin Radoslavov
193 The IPv6 PIM kernel support was implemented by the KAME project
194 .Pq Pa https://www.kame.net ,
195 and was based on the IPv4 PIM kernel support.
197 This manual page was written by
198 .An Pavlin Radoslavov