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Solution
Possible Problem
Status Line Condition
in the local router.
7
If you suspect faulty router
hardware, change the serial line
to an unused port. If the
connection comes up, the
previously connected interface
has a problem.
First enable per-interface
debugging using the
command
debug interface
serial x
, and depending on
the encapsulation, enable
the corresponding debug:
For HDLC:
debug serial
interface
For PPP:
debug
ppp negotiation
For FR:
debug frame-relay lmi
Note
Because debugging
output is assigned high
priority in the CPU
process, it can render
the system unusable.
For this reason, use
debug
commands only
to troubleshoot specific
problems or during
troubleshooting sessions
with Cisco technical
support staff. Moreover,
it is best to use
debug
commands during
periods of lower
network traffic and
fewer users. Debugging
during these periods
decreases the likelihood
that increased
debug
command processing
overhead will affect
system use.
Caution
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide, Cisco IOS XE
Everest 16.5
OL-14127-17
329
Troubleshooting the Serial SPAs
Serial Lines: show interfaces serial Status Line Conditions