IPXrouted -- IPX Routing Information Protocol daemon
IPXrouted [-N] [-q] [-s] [-S] [-t] [logfile]
The IPXrouted utility is invoked at boot time to manage the IPX routing
tables. The IPX routing daemon uses the Novell IPX Routing Information
Protocol in maintaining up to date kernel routing table entries.
Available options:
-N Do not reply on GetNearestServer SAP request.
-q Do not supply routing information (opposite of -s option below).
-s Forces IPXrouted to supply routing information whether it is
acting as an internetwork router or not.
-S Do not supply Service Advertising Protocol SAP information. The
default is to supply SAP information.
-t All packets sent or received are printed on the standard output.
In addition, IPXrouted will not divorce itself from the controlling
terminal so that interrupts from the keyboard will kill the
process.
logfile Name of file in which IPXrouted's actions should be logged.
This log contains information about any changes to the routing
tables and a history of recent messages sent and received which
are related to the changed route.
In normal operation IPXrouted listens for routing information packets.
If the host is connected to multiple IPX networks, it periodically supplies
copies of its routing tables to any directly connected hosts and
networks.
When IPXrouted is started, it uses the SIOCGIFCONF ioctl(2) to find those
directly connected interfaces configured into the system and marked
``up'' (the software loopback interface is ignored). If multiple interfaces
are present, it is assumed the host will forward packets between
networks. The IPXrouted utility then transmits a request packet on each
interface (using a broadcast packet if the interface supports it) and
enters a loop, listening for request and response packets from other
hosts.
When a request packet is received, IPXrouted formulates a reply based on
the information maintained in its internal tables. The response packet
generated contains a list of known routes, each marked with a ``hop
count'' metric (a count of 16, or greater, is considered ``infinite'').
The metric associated with each route returned provides a metric relative
to the sender.
Response packets received by IPXrouted are used to update the routing
tables if one of the following conditions is satisfied:
+o No routing table entry exists for the destination network or host,
and the metric indicates the destination is ``reachable'' (i.e. the
hop count is not infinite).
+o The source host of the packet is the same as the router in the existing
routing table entry. That is, updated information is being
received from the very internetwork router through which packets for
the destination are being routed.
+o The existing entry in the routing table has not been updated for some
time (defined to be 90 seconds) and the route is at least as cost
effective as the current route.
+o The new route describes a shorter route to the destination than the
one currently stored in the routing tables; the metric of the new
route is compared against the one stored in the table to decide this.
When an update is applied, IPXrouted records the change in its internal
tables and generates a response packet to all directly connected hosts
and networks. The routed(8) utility waits a short period of time (no
more than 30 seconds) before modifying the kernel's routing tables to
allow possible unstable situations to settle.
In addition to processing incoming packets, IPXrouted also periodically
checks the routing table entries. If an entry has not been updated for 3
minutes, the entry's metric is set to infinity and marked for deletion.
Deletions are delayed an additional 60 seconds to insure the invalidation
is propagated to other routers.
Hosts acting as internetwork routers gratuitously supply their routing
tables every 30 seconds to all directly connected hosts and networks.
If IPXrouted receives a SIGINFO signal the current contents of the RIP
and SAP tables are appended to the file /var/log/ipxrouted.dmp.
ipx(3)
The IPXrouted utility first appeared in FreeBSD 2.2.
FreeBSD 5.2.1 October 11, 1995 FreeBSD 5.2.1 [ Back ] |
