08-18-2007 04:42 PM - edited 03-05-2019 05:58 PM
Hello,
I'm playing with a couple of Cisco 1720's and trying to make them work. Each of them has 1 WIC 1DSU-T1 (http://www.cisco.com/en/US/products/hw/routers/ps221/products_data_sheet09186a00801a9184.html)
I reset both routers and configured onboard FastEthernet interfaces. However, I'm confused about these WIC's. They show up as Serial interfaces and I cannot bring them up.
I tried connecting them to each other and to a laptop via regular CAT5 cross-over cable, but all it shows is
Interface IP-Address OK? Method Status Prot
ocol
FastEthernet0 192.168.3.103 YES manual up down
Serial0 10.0.0.2 YES manual down down
(routers' configuration is provided below)
My questions are:
1. What am I doing wrong? Do I need to set up clock rate, etc for this "serial" interfaces?
2. Can I troubleshoot these 1DSU-T1 WIC's with a cross-over cable and a laptop at all? (Linux 2.6.8 with regular Ethernet interface)
Thanks in advance for any help!
08-18-2007 04:42 PM
P.S. Here's the routers' configuration:
test1#show interfaces serial 0
Serial0 is down, line protocol is down
Hardware is PQUICC with Fractional T1 CSU/DSU
Internet address is 10.0.0.1/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 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: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue :0/40 (size/max)
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, 3 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=down DSR=up DTR=up RTS=up CTS=down
test1#show running-config
Building configuration...
Current configuration : 601 bytes
!
version 12.1
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname test1
!
!
!
memory-size iomem 25
ip subnet-zero
!
!
!
!
interface Serial0
ip address 10.0.0.1 255.255.255.0
no fair-queue
!
interface FastEthernet0
ip address 192.168.2.104 255.255.255.0
speed auto
!
ip classless
ip http server
!
!
line con 0
login
line aux 0
line vty 0 4
login
!
end
------------------------------
test2#show interfaces serial 0
Serial0 is down, line protocol is down
Hardware is PQUICC with Fractional T1 CSU/DSU
Internet address is 10.0.0.2/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 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 00:15:29
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
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, 6 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=down DSR=up DTR=up RTS=up CTS=down
test2# show running-config
Building configuration...
Current configuration:
!
version 12.1
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname test2
!
!
!
!
!
memory-size iomem 25
ip subnet-zero
!
!
!
!
interface Serial0
ip address 10.0.0.2 255.255.255.0
no fair-queue
!
interface FastEthernet0
ip address 192.168.3.103 255.255.255.0
speed auto
!
ip classless
ip http server
!
!
line con 0
login
transport input none
line aux 0
line vty 0 4
login
!
no scheduler allocate
end
08-19-2007 04:30 AM
The biggest problem is your crossover cable. An Ethernet crossover will cross 1, 2 and 3, 6 but a T1 serial crossover will cross 1, 2 and 4, 5. You can not use standard Ethernet crossover to connect serial interfaces.
Once you get a correct crossover cable you will also need to configure one of the routers for clocking internal and to configure a clock rate.
HTH
Rick
08-19-2007 10:32 AM
Thank you Rick!
08-19-2007 07:10 PM
You are quite welcome. Thank you for the rating.
HTH
Rick
08-20-2007 11:55 AM
The correct command to see the status of the physical serial port is 'show controller serial'.
Also, the status of the T1 DSU is seen with the command 'show service-module'.
Please note that a Cat5 patch cable may short-out one or both of the CSU's if used to connect back-to-back.
Be sure to *only* use a cable with pins 1,2,4 and 5 connected. *DO NOT* cross-connect *any* other pins!!! A T1 should specifically *not* be grounded on pins 3 or 6, particularly between 2 cross-connected routers.
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