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328 Chapter 5: Network Protocols
Scenarios
Scenario 5-1: IP Addressing and Subnet Calculation
Assume that you just took a new job. No one trusts you yet, so they will not give you any
passwords to the router. Your mentor at your new company has left you at his desk while he goes
to a meeting. He has left a Telnet window up, logged in to one router in user mode. In other
words, you can issue only user mode commands.
Assuming that you had issued the following commands (see Example 5-28), draw the most
specific network diagram that you can. Write the subnet numbers used on each link onto the
diagram.
Example 5-28
Command Output on Router Fred
fred>show interface
Serial0 is up, line protocol is up
Hardware is HD64570
Internet address is 199.1.1.65/27
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation HDLC, loopback not set, keepalive set (10 sec)
Last input 00:00:07, output 00:00:10, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queuing strategy: weighted fair
Output queue: 0/1000/0 (size/max total/drops)
Conversations 0/1/64 (active/max active/threshold)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
27 packets input, 2452 bytes, 0 no buffer
Received 27 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
29 packets output, 2044 bytes, 0 underruns
0 output errors, 0 collisions, 28 interface resets
0 output buffer failures, 0 output buffers swapped out
7 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
Serial1 is up, line protocol is up
Hardware is HD64570
Internet address is 199.1.1.97/27
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation HDLC, loopback not set, keepalive set (10 sec)
Last input 00:00:01, output 00:00:01, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queuing strategy: weighted fair
Output queue: 0/1000/0 (size/max total/drops)
Conversations 0/1/64 (active/max active/threshold)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
ch05.fm Page 328 Monday, March 20, 2000 5:06 PM