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18916298 RG |
1 | .\" Copyright (c) 1986, 1991 The Regents of the University of California. |
2 | .\" All rights reserved. | |
3 | .\" | |
4 | .\" Redistribution and use in source and binary forms, with or without | |
5 | .\" modification, are permitted provided that the following conditions | |
6 | .\" are met: | |
7 | .\" 1. Redistributions of source code must retain the above copyright | |
8 | .\" notice, this list of conditions and the following disclaimer. | |
9 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
10 | .\" notice, this list of conditions and the following disclaimer in the | |
11 | .\" documentation and/or other materials provided with the distribution. | |
12 | .\" 3. All advertising materials mentioning features or use of this software | |
13 | .\" must display the following acknowledgement: | |
14 | .\" This product includes software developed by the University of | |
15 | .\" California, Berkeley and its contributors. | |
16 | .\" 4. Neither the name of the University nor the names of its contributors | |
17 | .\" may be used to endorse or promote products derived from this software | |
18 | .\" without specific prior written permission. | |
19 | .\" | |
20 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
21 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
22 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
23 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
24 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
25 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
26 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
27 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
28 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
29 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
30 | .\" SUCH DAMAGE. | |
31 | .\" | |
32 | .\" @(#)XNSrouted.8 6.4 (Berkeley) 3/16/91 | |
33 | .\" | |
34 | .Dd March 16, 1991 | |
35 | .Dt XNSROUTED 8 | |
36 | .Os BSD 4.3 | |
37 | .Sh NAME | |
38 | .Nm XNSrouted | |
39 | .Nd NS Routing Information Protocol daemon | |
40 | .Sh SYNOPSIS | |
41 | .Nm XNSrouted | |
42 | .Op Fl q | |
43 | .Op Fl s | |
44 | .Op Fl t | |
45 | .Op Ar logfile | |
46 | .Sh DESCRIPTION | |
47 | .Nm XNSrouted | |
48 | is invoked at boot time to manage the Xerox NS routing tables. | |
49 | The NS routing daemon uses the Xerox NS Routing | |
50 | Information Protocol in maintaining up to date kernel routing | |
51 | table entries. | |
52 | .Pp | |
53 | Available options: | |
54 | .Bl -tag -width logfile | |
55 | .It Fl q | |
56 | Do not supply routing information (opposite of | |
57 | .Fl s | |
58 | option below). | |
59 | .It Fl s | |
60 | Forces | |
61 | .Nm XNSrouted | |
62 | to supply routing information whether it is acting as an internetwork | |
63 | router or not. | |
64 | .It Fl t | |
65 | All packets sent or received are | |
66 | printed on the standard output. In addition, | |
67 | .Nm XNSrouted | |
68 | will not divorce itself from the controlling terminal | |
69 | so that interrupts from the keyboard will kill the process. | |
70 | .It Ar logfile | |
71 | Name of file in which | |
72 | .Nm XNSrouted Ns 's | |
73 | actions should be logged. This log contains information | |
74 | about any changes to the routing tables and a history of | |
75 | recent messages sent and received which are related to | |
76 | the changed route. | |
77 | .El | |
78 | .Pp | |
79 | In normal operation | |
80 | .Nm XNSrouted | |
81 | listens | |
82 | for routing information packets. If the host is connected to | |
83 | multiple NS networks, it periodically supplies copies | |
84 | of its routing tables to any directly connected hosts | |
85 | and networks. | |
86 | .Pp | |
87 | When | |
88 | .Nm XNSrouted | |
89 | is started, it uses the | |
90 | .Dv SIOCGIFCONF | |
91 | .Xr ioctl 2 | |
92 | to find those | |
93 | directly connected interfaces configured into the | |
94 | system and marked | |
95 | .Dq up | |
96 | (the software loopback interface | |
97 | is ignored). If multiple interfaces | |
98 | are present, it is assumed the host will forward packets | |
99 | between networks. | |
100 | .Nm XNSrouted | |
101 | then transmits a | |
102 | .Em request | |
103 | packet on each interface (using a broadcast packet if | |
104 | the interface supports it) and enters a loop, listening | |
105 | for | |
106 | .Em request | |
107 | and | |
108 | .Em response | |
109 | packets from other hosts. | |
110 | .Pp | |
111 | When a | |
112 | .Em request | |
113 | packet is received, | |
114 | .Nm XNSrouted | |
115 | formulates a reply based on the information maintained in its | |
116 | internal tables. The | |
117 | .Em response | |
118 | packet generated contains a list of known routes, each marked | |
119 | with a | |
120 | .Dq hop count | |
121 | metric (a count of 16, or greater, is | |
122 | considered | |
123 | .Dq infinite ) . | |
124 | The metric associated with each | |
125 | route returned provides a metric | |
126 | .Em relative to the sender . | |
127 | .Pp | |
128 | .Em Response | |
129 | packets received by | |
130 | .Nm XNSrouted | |
131 | are used to update the routing tables if one of the following | |
132 | conditions is satisfied: | |
133 | .Bl -bullet | |
134 | .It | |
135 | No routing table entry exists for the destination network | |
136 | or host, and the metric indicates the destination is ``reachable'' | |
137 | (i.e. the hop count is not infinite). | |
138 | .It | |
139 | The source host of the packet is the same as the router in the | |
140 | existing routing table entry. That is, updated information is | |
141 | being received from the very internetwork router through which | |
142 | packets for the destination are being routed. | |
143 | .It | |
144 | The existing entry in the routing table has not been updated for | |
145 | some time (defined to be 90 seconds) and the route is at least | |
146 | as cost effective as the current route. | |
147 | .It | |
148 | The new route describes a shorter route to the destination than | |
149 | the one currently stored in the routing tables; the metric of | |
150 | the new route is compared against the one stored in the table | |
151 | to decide this. | |
152 | .El | |
153 | .Pp | |
154 | When an update is applied, | |
155 | .Nm XNSrouted | |
156 | records the change in its internal tables and generates a | |
157 | .Em response | |
158 | packet to all directly connected hosts and networks. | |
159 | .Xr Routed 8 | |
160 | waits a short period | |
161 | of time (no more than 30 seconds) before modifying the kernel's | |
162 | routing tables to allow possible unstable situations to settle. | |
163 | .Pp | |
164 | In addition to processing incoming packets, | |
165 | .Nm XNSrouted | |
166 | also periodically checks the routing table entries. | |
167 | If an entry has not been updated for 3 minutes, the entry's metric | |
168 | is set to infinity and marked for deletion. Deletions are delayed | |
169 | an additional 60 seconds to insure the invalidation is propagated | |
170 | to other routers. | |
171 | .Pp | |
172 | Hosts acting as internetwork routers gratuitously supply their | |
173 | routing tables every 30 seconds to all directly connected hosts | |
174 | and networks. | |
175 | .Sh SEE ALSO | |
176 | .Xr idp 4 | |
177 | .Rs | |
178 | .%T "Internet Transport Protocols" | |
179 | .%R "XSIS 028112" | |
180 | .%Q "Xerox System Integration Standard" | |
181 | .Re | |
182 | .Sh HISTORY | |
183 | The | |
184 | .Nm | |
185 | command appeared in | |
186 | .Bx 4.3 . |