Hi,
The reason for this is that although RIP treats these two networks as
separate entries residing on the SAME physical link, only the PRIMARY
address is used to send the packets. In other words, the 2ndary networks
are reliant on the primary address for delivering the packets. 2ndaries
are used solely for reachability issues in discontiguous networks which
is a problem for pure Distance-Vector protocols. Consider the debug
output...
MC3810b#trace 192.168.83.244
Type escape sequence to abort.
Tracing the route to 192.168.83.244
1 192.168.12.195 4 msec * 0 msec
2 192.168.83.244 12 msec * *
MC3810b#trace 10.33.55.1
Type escape sequence to abort.
Tracing the route to 10.33.55.1
1 192.168.12.195 8 msec 4 msec 4 msec
2 192.168.83.244 8 msec
09:33:24: ICMP: time exceeded rcvd from 192.168.12.195
09:33:24: ICMP: time exceeded rcvd from 192.168.12.195
09:33:24: ICMP: time exceeded rcvd from 192.168.12.195
09:33:24: ICMP: dst (192.168.12.196) port unreachable rcv from
192.168.83.244 * 4 msec
MC3810b#
09:33:27: ICMP: dst (192.168.12.196) port unreachable rcv from
192.168.83.244
MC3810b#trace 10.33.55.1
Type escape sequence to abort.
Tracing the route to 10.33.55.1
1 192.168.12.195 4 msec 0 msec 4 msec
2 192.168.83.244 8 msec * 4 msec
MC3810b#
09:32:04: ICMP: echo reply rcvd, src 10.33.55.1, dst 192.168.12.196
09:32:04: ICMP: echo reply rcvd, src 10.33.55.1, dst 192.168.12.196
09:32:04: ICMP: echo reply rcvd, src 10.33.55.1, dst 192.168.12.196
09:32:04: ICMP: echo reply rcvd, src 10.33.55.1, dst 192.168.12.196
09:32:04: ICMP: echo reply rcvd, src 10.33.55.1, dst 192.168.12.196
Also, examine the entries in the routing table...
MC3810b#sh ip route 10.33.55.1
Routing entry for 10.33.48.0/20
Known via "rip", distance 120, metric 1
Redistributing via rip
Last update from 10.33.75.1 on Ethernet0, 00:00:15 ago
Routing Descriptor Blocks:
* 10.33.75.1, from 10.33.75.1, 00:00:15 ago, via Ethernet0
Route metric is 1, traffic share count is 1
MC3810b#sh ip route 192.168.83.244
Routing entry for 192.168.83.0/24
Known via "rip", distance 120, metric 1
Redistributing via rip
Last update from 10.33.75.1 on Ethernet0, 00:00:02 ago
Routing Descriptor Blocks:
* 192.168.12.195, from 192.168.12.195, 00:00:02 ago, via Ethernet0
Route metric is 1, traffic share count is 1
10.33.75.1, from 10.33.75.1, 00:00:02 ago, via Ethernet0
Route metric is 1, traffic share count is 1
I hope this answers your question. Take care.
Elmer
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Monday, January 20, 2003 5:16 AM
To: [EMAIL PROTECTED]
Subject: jeff's routing tcp/ip v1 question [7:61360]
For Jeff's routing tcp/ip V1 book, page 214 and 215 . There is a
secondly
ip address , for rip version 1 because of the discontinues 10.0.0.0. So
why
there is only one route to 10.33.48.0 , and two route to 192.168.83.0 in
the
routing table of Ernest_T ?
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=61643&t=61360
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