xref: /freebsd/share/man/man4/ng_one2many.4 (revision 6780ab54325a71e7e70112b11657973edde8655e)
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33.\" Author: Archie Cobbs <archie@FreeBSD.org>
34.\"
35.\" $FreeBSD$
36.\"
37.Dd January 26, 2001
38.Dt NG_ONE2MANY 4
39.Os
40.Sh NAME
41.Nm ng_one2many
42.Nd packet multiplexing netgraph node type
43.Sh SYNOPSIS
44.In sys/types.h
45.In netgraph/ng_one2many.h
46.Sh DESCRIPTION
47The
48.Nm one2many
49provides a simple mechanism for routing packets over several links
50in a one-to-many (and in the reverse direction, many-to-one) fashion.
51There is a single hook named
52.Dv one ,
53and multiple hooks named
54.Dv many0 ,
55.Dv many1 ,
56etc.
57Packets received on any of the
58.Dv many
59hooks are forwarded out the
60.Dv one
61hook.
62Packets received on the
63.Dv one
64hook are forwarded out one or more of the
65.Dv many
66hooks; which hook(s) is determined by the node's configured
67transmit algorithm.
68Packets are not altered in any way.
69.Pp
70Each of the connected many links may be considered to be up or down.
71Packets are never delivered out a many hook that is down.
72How a link is determined to be up or down depends on the node's
73configured link failure detection algorithm.
74.Sh TRANSMIT ALGORITHMS
75.Bl -tag -width foo
76.It NG_ONE2MANY_XMIT_ROUNDROBIN
77Packets are delivered out the many hooks in sequential order.
78Each packet goes out on a different
79.Dv many
80hook.
81.It NG_ONE2MANY_XMIT_ALL
82Packets are delivered out all the
83.Dv many
84hooks. Each packet goes out each
85.Dv many
86hook.
87.El
88.Pp
89In the future other algorithms may be added as well.
90.Sh LINK FAILURE DETECTION
91At this time, the only algorithm for determining when a link
92has failed, other than the hook being disconnected, is the
93``manual'' algorithm: the node is explicitly told which of
94the links are up via the
95.Dv NGM_ONE2MANY_SET_CONFIG
96control message (see below).
97Newly connected links are down until configured otherwise.
98.Pp
99In the future other algorithms may be added as well.
100.Sh HOOKS
101This node type supports up to
102.Dv NG_ONE2MANY_MAX_LINKS
103hooks named
104.Dv many0 ,
105.Dv many1 ,
106etc.,
107plus a single hook named
108.Dv one .
109.Sh CONTROL MESSAGES
110This node type supports the generic control messages, plus the
111following:
112.Bl -tag -width foo
113.It Dv NGM_ONE2MANY_SET_CONFIG
114Sets the node configuration using a
115.Dv "struct ng_one2many_link_config"
116as the control message argument:
117.Bd -literal -offset 0n
118/* Node configuration structure */
119struct ng_one2many_config {
120  u_int32_t   xmitAlg;        /* how to distribute packets */
121  u_int32_t   failAlg;        /* how to detect link failure */
122  u_char      enabledLinks[NG_ONE2MANY_MAX_LINKS];
123};
124.Ed
125.Pp
126Currently, the only valid setting for the
127.Dv xmitAlg
128field is
129.Dv NG_ONE2MANY_XMIT_ROUNDROBIN ;
130this is also the default setting.
131The only valid setting for
132.Dv failAlg
133is
134.Dv NG_ONE2MANY_FAIL_MANUAL ;
135this is also the default setting.
136.It Dv NGM_ONE2MANY_GET_CONFIG
137Returns the current node configuration in a
138.Dv "struct ng_one2many_link_config" .
139.It Dv NGM_ONE2MANY_GET_STATS
140This command takes a 32 bit link number as an argument and
141returns a
142.Dv "struct ng_one2many_link_stats"
143containing statistics for the corresponding
144.Dv many
145link, which may or may not be currently connected:
146.Bd -literal -offset 0n
147/* Statistics structure (one for each link) */
148struct ng_one2many_link_stats {
149  u_int64_t   recvOctets;     /* total octets rec'd on link */
150  u_int64_t   recvPackets;    /* total pkts rec'd on link */
151  u_int64_t   xmitOctets;     /* total octets xmit'd on link */
152  u_int64_t   xmitPackets;    /* total pkts xmit'd on link */
153};
154.Ed
155.Pp
156To access statistics for the
157.Dv one
158link, use the link number
159.Dv -1 .
160.It Dv NGM_ONE2MANY_CLR_STATS
161This command takes a 32 bit link number as an argument and
162clears the statistics for that link.
163.It Dv NGM_ONE2MANY_GETCLR_STATS
164Same as
165.Dv NGM_ONE2MANY_GET_STATS ,
166but also atomically clears the statistics for the link as well.
167.El
168.Sh SHUTDOWN
169This node shuts down upon receipt of a
170.Dv NGM_SHUTDOWN
171control message, or when all hooks have been disconnected.
172.Sh EXAMPLES
173The following commands will set up Ethernet interfaces
174.Dv fxp0
175to deliver packets alternating over the physical interfaces
176corresponding to networking interfaces
177.Dv fxp0
178through
179.Dv fxp3 :
180.Bd -literal -offset 0n
181  # Plumb nodes together
182  ngctl mkpeer fxp0: one2many upper one
183  ngctl connect fxp0: fxp0:upper lower many0
184  ngctl connect fxp1: fxp0:upper lower many1
185  ngctl connect fxp2: fxp0:upper lower many2
186  ngctl connect fxp3: fxp0:upper lower many3
187  # Allow fxp1 through fxp3 to xmit/recv fxp0 frames
188  ngctl msg fxp1: setpromisc 1
189  ngctl msg fxp2: setpromisc 1
190  ngctl msg fxp3: setpromisc 1
191  ngctl msg fxp1: setautosrc 0
192  ngctl msg fxp2: setautosrc 0
193  ngctl msg fxp3: setautosrc 0
194  # Configure all four links as up
195  ngctl msg fxp0:upper \\
196    setconfig "{ xmitAlg=1 failAlg=1 enabledLinks=[ 1 1 1 1 ] }"
197  # Bring up interface
198  ifconfig fxp0 192.168.1.1 netmask 0xfffffffc
199.Ed
200.Pp
201With a similar setup on a peer machine (using the address
202192.168.1.2), a point-to-point
203Ethernet connection with four times normal bandwidth is
204achieved.
205.Sh BUGS
206More transmit and link failure algorithms should be supported.
207A good candidate is Cisco's Etherchannel.
208.Sh SEE ALSO
209.Xr netgraph 4 ,
210.Xr ng_bridge 4 ,
211.Xr ng_ether 4 ,
212.Xr ngctl 8
213.Sh HISTORY
214The
215.Nm
216node type was implemented in
217.Fx 4.2 .
218.Sh AUTHORS
219.An -nosplit
220The
221.Nm one2many
222netgraph node (with round-robin algorithm) was written by
223.An Archie Cobbs
224.Aq archie@FreeBSD.org .
225The all algorithm was added by
226.An Rogier R. Mulhuijzen
227.Aq drwilco@drwilco.net .
228