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Router connections

Dubuku57

Hi,

Im using packet tracer 5.1 to practice for CCNA.

I connected 2 Routers(1841) with 2 serial lines.

RouterA S0/0/0 -- RouterB S0/0/0
RouterA S0/0/1 -- RouterB S0/0/1

This is the status after setting up the network>>

Serial0/0/0 is up, line protocol is down (disabled)
Serial0/0/1 is up, line protocol is up (connected)

Does this mean that there cannot be 2 serial line connections to the same router? I did the "no shutdown", "clock rate 64000" commands also. Im confused!! Please help me, someone!

Thanks alot in advance,

Dubuku57

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Comments

networker050184

Not sure about any restrictions with packet tracer never used it, but on real equipment you can definitely have two (or more) serial connections between routers.

Post the interface configs from both sides and we can probably help you out.

Dubuku57

Hello networker050184,

Here are the configs for the interfaces of Router A:

RouterA#sh int serial0/0/0
Serial0/0/0 is up, line protocol is down (disabled)
Hardware is HD64570
Internet address is 192.168.2.1/24
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 never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/0/256 (active/max active/max total)
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
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

RouterA#sh int serial0/0/1
Serial0/0/1 is up, line protocol is up (connected)
Hardware is HD64570
Internet address is 192.168.10.1/24
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 never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/0/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 15 bits/sec, 0 packets/sec
5 minute output rate 13 bits/sec, 0 packets/sec
9 packets input, 630 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
7 packets output, 490 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

Here are the configs for the interfaces of Router B:

RouterB#sh int serial0/0/0
Serial0/0/0 is up, line protocol is down (disabled)
Hardware is HD64570
Internet address is 192.168.2.2/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation PPP, loopback not set, keepalive set (10 sec)
LCP Closed
Closed: LEXCP, BRIDGECP, IPCP, CCP, CDPCP, LLC2, BACP
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/0/256 (active/max active/max total)
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
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

RouterB#sh int serial0/0/1
Serial0/0/1 is up, line protocol is up (connected)
Hardware is HD64570
Internet address is 192.168.10.2/24
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 never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/0/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 20 bits/sec, 0 packets/sec
5 minute output rate 20 bits/sec, 0 packets/sec
14 packets input, 980 bytes, 0 no buffer
Received 13 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
12 packets output, 840 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

1) Why is serial0/0/0 line protocol down? Line protocol doesnt refer to routing protocol right?

2) For a routing protocol(say RIP) there can be up to 6 equal cost paths to the same destination, right? So means i can have 6 serial links between the 2 routers? Is my understanding here correct?

Thanks lot!

kryolla

*hint* look at the encapsulation

line protocol is layer 2

Dubuku57

Yay! Thanks you!!

2) For a routing protocol(say RIP) there can be up to 6 equal cost paths to the same destination, right? So means i can have 6 serial links between the 2 routers? Is my understanding here correct?

Pls advice on the above too? thanks lot.

kryolla

Dubuku57 wrote: »

Yay! Thanks you!!

2) For a routing protocol(say RIP) there can be up to 6 equal cost paths to the same destination, right? So means i can have 6 serial links between the 2 routers? Is my understanding here correct?

Pls advice on the above too? thanks lot.

sure if you have 6 physical interfaces but it could mean different paths betweens different routers with maybe 2 going to same router for redundancy but sure you can have all 6 going to the same router if you choose.

Dubuku57

Thank you for your timely help!

Stotic

You seem to have solved your problem (wrong encapsulation on one of the routers). For future reference, when someone asks for a config they usually want the sh run output and will ask for specific show commands when necessary. Luckily the encap can be seen with the sh int command.

Dubuku57

Oh, i see..okay will take note of that in future.