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893-741-B
A12-5
Internet Protocol (IP) Routing
RIP Versions
The Model 5390 server supports both RIP version 1 (STD 34, RFC 1058) and RIP version 2 (RFC
1388). RIP 2 is a backward-compatible extension of RIP 1 that expands the amount of information
carried in RIP updates and authenticates them using passwords. RIP 2 broadcasts or multicasts
updates, depending on whether or not updates are to be sent to RIP 1 as well as RIP 2 systems.
Route Cache and Routing Table
The Model 5390 server stores IP routes in two places: the route cache and the routing table.
Route Cache
The route cache contains user-configured routing information – static routes, and sometimes a
default route. The Model 5390 server can learn default routes through RIP updates as well as from
you, which is why all default routes are not necessarily cached.
The Model 5390 server copies static and default routes to the route cache from the
gateway
section
of the Model 5390 configuration file (see
Defining Routes
on page A12-22) and/or from routes you
define via the CLI superuser
route
command (see
Entering Routes using the route Command
on
page A12-42).
Routes in the cache include those whose next hops are directly reachable —that is, up and running
on a network directly connected to the Model 5390 server – and those that are not yet reachable.
Routes with reachable next hops are immediately copied to the RIP routing table. Routes whose
next hops are not yet directly reachable are copied to the routing table as soon as their next hops
become reachable. The latter technique saves the Model 5390 server the trouble of consulting the
configuration file, which typically is not stored on the Model 5390 server, each time a route’s status
changes. A copy of the route remains in the routing cache, in case its next hop becomes unreachable
again.
The route cache also contains backup routes if two routes in the routing table have the same
destination interface. In this case, one of the routes is removed from the routing table and stored in
the cache, as follows:
•
If one of the routes is for dial-out and the other is not, the dial-out route is moved to the cache.
CAUTION:
Not all routers support RIP version 2. Check the RIP ver-
sions running on the routers on your network before configuring RIP on
the Model 5390 server.
Содержание 5390
Страница 28: ...893 741 B Figures xxviii ...
Страница 44: ...893 741 B Preface xliv ...
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Страница 60: ...A1 12 893 741 B Introduction to the Model 5390 Server ...
Страница 106: ...A3 18 893 741 B Configuring Ports ...
Страница 142: ...A5 12 893 741 B Printers ...
Страница 152: ...A6 10 893 741 B Modems ...
Страница 168: ...A7 16 893 741 B Serial Line Internet Protocol SLIP ...
Страница 224: ...A9 38 893 741 B Internetwork Packet Exchange IPX Protocol ...
Страница 258: ...A11 12 893 741 B Dial up Networking ...
Страница 289: ...893 741 B A12 31 Internet Protocol IP Routing that are possible ...
Страница 506: ...A15 86 893 741 B Using Model 5390 Security ...
Страница 507: ......
Страница 508: ... Chapter B1 Network Administration Chapter B2 Simple Network Management Protocol SNMP Part B Network Administration ...
Страница 544: ...B1 36 893 741 B Network Administration ...
Страница 574: ...B2 30 893 741 B Simple Network Management Protocol SNMP ...
Страница 575: ......
Страница 606: ...C1 30 893 741 B na Commands ...
Страница 676: ...C2 70 893 741 B Configuration Parameters ...
Страница 772: ...C3 96 893 741 B Using the CLI Commands ...
Страница 794: ...C5 12 893 741 B Network Protocols ...
Страница 795: ......
Страница 796: ... Appendix D1 Software Reference Part D Appendixes ...