1XNSROUTED(8) System Manager's Manual XNSROUTED(8)
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6 XNSrouted - NS Routing Information Protocol daemon
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9 /sbin/XNSrouted [ -s ] [ -q ] [ -t ] [ logfile ]
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12 XNSrouted is invoked at boot time to manage the Xerox NS routing
13 tables. The NS routing daemon uses the Xerox NS Routing Information
14 Protocol in maintaining up to date kernel routing table entries.
15 In normal operation XNSrouted listens for routing information packets.
17 If the host is connected to multiple NS networks, it periodically sup‐
18 plies copies of its routing tables to any directly connected hosts and
19 networks.
20 When XNSrouted is started, it uses the SIOCGIFCONF ioctl to find those
22 directly connected interfaces configured into the system and marked
23 ``up'' (the software loopback interface is ignored). If multiple
24 interfaces are present, it is assumed the host will forward packets
25 between networks. XNSrouted then transmits a request packet on each
26 interface (using a broadcast packet if the interface supports it) and
27 enters a loop, listening for request and response packets from other
28 hosts.
29 When a request packet is received, XNSrouted formulates a reply based
31 on the information maintained in its internal tables. The response
32 packet generated contains a list of known routes, each marked with a
33 ``hop count'' metric (a count of 16, or greater, is considered ``infi‐
34 nite''). The metric associated with each route returned provides a
35 metric relative to the sender.
36 Response packets received by XNSrouted are used to update the routing
38 tables if one of the following conditions is satisfied:
39 (1) No routing table entry exists for the destination network or
41 host, and the metric indicates the destination is ``reachable''
42 (i.e. the hop count is not infinite).
43 (2) The source host of the packet is the same as the router in the
45 existing routing table entry. That is, updated information is
46 being received from the very internetwork router through which
47 packets for the destination are being routed.
48 (3) The existing entry in the routing table has not been updated for
50 some time (defined to be 90 seconds) and the route is at least
51 as cost effective as the current route.
52 (4) The new route describes a shorter route to the destination than
54 the one currently stored in the routing tables; the metric of
55 the new route is compared against the one stored in the table to
56 decide this.
57 When an update is applied, XNSrouted records the change in its internal
59 tables and generates a response packet to all directly connected hosts
60 and networks. Routed waits a short period of time (no more than 30
61 seconds) before modifying the kernel's routing tables to allow possible
62 unstable situations to settle.
63 In addition to processing incoming packets, XNSrouted also periodically
65 checks the routing table entries. If an entry has not been updated for
66 3 minutes, the entry's metric is set to infinity and marked for dele‐
67 tion. Deletions are delayed an additional 60 seconds to insure the
68 invalidation is propagated to other routers.
69 Hosts acting as internetwork routers gratuitously supply their routing
71 tables every 30 seconds to all directly connected hosts and networks.
72 Supplying the -s option forces XNSrouted to supply routing information
74 whether it is acting as an internetwork router or not. The -q option
75 is the opposite of the -s option. If the -t option is specified, all
76 packets sent or received are printed on the standard output. In addi‐
77 tion, XNSrouted will not divorce itself from the controlling terminal
78 so that interrupts from the keyboard will kill the process. Any other
79 argument supplied is interpreted as the name of file in which
80 XNSrouted's actions should be logged. This log contains information
81 about any changes to the routing tables and a history of recent mes‐
82 sages sent and received which are related to the changed route.
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85 ``Internet Transport Protocols'', XSIS 028112, Xerox System Integration
86 Standard.
87 idp(4P)
884.3 Berkeley Distribution November 1, 1996 XNSROUTED(8)