Troubleshooting Serial Lines
389
.
. {some output omitted}
.
TX ring with 2 entries at 0x423800
.
. {some output omitted}
.
0 missed datagrams, 0 overruns
0 bad datagram encapsulations, 0 memory errors
0 transmitter underruns
0 residual bit errors
Router_A#
The basic information provided by this command is the interface status
regarding missed datagrams, overruns, bad encapsulation, memory errors,
underruns, and bit errors. In addition, it indicates the interface clock rate,
as well as the cable type that is connected to the interface.
If you don't see a cable connected to the interface, verifying that a cable
is properly connected is a good item to include in a troubleshooting action
plan. If there are excessive errors on the interface, it can be faulty hardware.
show buffers Command
The show buffers command can be used to look at system buffer pools, but
it also provides information regarding interface buffers. Look at the sample
output from a 2514 router:
Router_B>show buffers
Buffer elements:
500 in free list (500 max allowed)
52587626 hits, 0 misses, 0 created
Public buffer pools:
Small buffers, 104 bytes (total 50, permanent 50):
50 in free list (20 min, 150 max allowed)
7709985 hits, 0 misses, 0 trims, 0 created
0 failures (0 no memory)
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