try doing the loopback test on you side. use the loopback cable. plug it
into the csu/dsu, and wait to see if the line protocol will come up. of
course, before that, you have to change the encap to hdlc.
The T1 CSU/DSU has a different pinout than the four-wire 56K CSU/DSU. The
connector for the T1 CSU/DSU is an RJ-48C. The connector for the four-wire
56k CSU/DSU is an RJ-48S. Both connectors are compatible with RJ-45 plugs.
Instructions for creating loopback plugs for each one is shown below:
Complete the following steps to create a loopback plug for a T1 CSU/DSU:
Use wire cutters to cut a working RJ-45 cable that is 5 inches long with a
connector attached.
Strip the wires.
Twist the wires from pins 1 and 4 together.
Twist the wires from pins 2 and 5 together.
Leave the rest of the wires alone.
Complete the following steps to create a loopback plug for a 56K CSU/DSU:
Use wire cutters to cut a working RJ-45 cable that is 5 inches long with a
connector attached.
Strip the wires.
Twist the wires from pins 1 and 7 together.
Twist the wires from pins 2 and 8 together.
Leave the rest of the wires alone.
Diagnostic Tests while in Loopback
The best test to run while in any of the loopbacks described above is an
extend ping. You should run this test and monitor the show interface serial
command for errors on the interface. This test is described below:
Preparing for the Extended Ping Test
Complete these steps to prepare for the extended ping test:
Use the show interface serial command to verify that the router has hdlc
encapsulation on the interface, and that the interface sees the loopback. An
example of the first few lines of the output is shown below:
Router#show interface serial 0
Serial0 is up, line protocol is up (looped)
Hardware is HD64570
Internet address is 10.1.1.1, subnet mask is 255.255.255.0
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation HDLC, loopback set, keepalive set (10 sec)
...
Use the show running-config command to see if the interface has a unique IP
address that is not shared with any other interface. If the serial interface
above does not have an IP address of it's own, obtain a unique address and
assign it to the interface.
Router(config-if)#ip address 172.22.53.1 255.255.255.0
Clear the interface counters using the clear counters command. For example:
Router#clear counters
Clear "show interface" counters on all interfaces [confirm]
Router#
Perform the extended ping test as described in the "Performing Extended Ping
Tests" section shown below.
Performing Extended Ping Tests
The ping command is a useful test available on Cisco internetworking devices
as well as on many host systems. In TCP/IP, this diagnostic tool is also
known as an Internet Control Message Protocol (ICMP) Echo Request.
Note:The ping command is particularly useful when high levels of input
errors are being registered in the show interfaces serial output.
Cisco internetworking devices provide a mechanism to automate the sending of
many ping packets in sequence.
Complete the following steps to perform serial line extended ping tests:
Follow these steps to perform the extended ping test:
Type: ping ip
Target address = enter the IP address of the local interface to which IP
address was just assigned
Repeat count = 50
Datagram size = 1500
Timeout = press ENTER
Extended cmds = yes
Source Address = press ENTER
Type of service = press ENTER
Set Df bit in ip header = press ENTER
Validate reply data = press ENTER
Data pattern: 0x0000
Press ENTER three times.
Notice that the ping packet size is 1500 bytes, and that we are performing
an all zeros ping (0x0000). Also, the ping count specification is set to 50.
Therefore, in this case, there are fifty 1500 byte ping packets sent out.
A sample output is below:
Router#ping ip
Target IP address: 172.22.53.1
Repeat count [5]: 50
Datagram size [100]: 1500
Timeout in seconds [2]:
Extended commands [n]: yes
Source address or interface:
Type of service [0]:
Set DF bit in IP header? [no]:
Validate reply data? [no]:
Data pattern [0xABCD]: 0x0000
Loose, Strict, Record, Timestamp, Verbose[none]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 50, 1500-byte ICMP Echos to 172.22.53.1, timeout is 2 seconds:
Packet has data pattern 0x0000
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (50/50), round-trip min/avg/max = 4/4/8 ms
Router#
Perform additional extended ping tests with different data patterns. For
example:
Repeat step 1, but use a Data Pattern of 0x1111
Repeat step 1, but use a Data Pattern of 0xffff
Repeat step 1, but use a Data Pattern of 0xaaaa
Verify that all the extended ping tests were 100 percent successful.
Examine the show interface serial command output and determine if input
errors have increased. If input errors have not increased, the local
hardware (DSU, cable, router interface card) is probably in good condition.
Also look for cyclic redundancy check (CRC), frame, or other errors. Verify
this by looking at the fifth and sixth line from the bottom of the show
interface serial command output.
If all pings are 100 percent successful and input errors have not increased,
the equipment in this portion of the circuit is probably in good condition.
Move on to the next loopback test to be performed..
Remove the loopback from the interface (by removing the loopback plug, the
software loopback commands, or request the telco to remove their loopback)
and restore your router to the original setting.
hope this helps to see where the problem is.
Dragi
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=8702&t=8648
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
