Serial Lines: show interfaces serial Status Line Conditions
Status Line Condition
Serial x is down, line protocol is
down
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide, Cisco IOS
XE Everest 16.5
326
Possible Problem
The router is not sensing a carrier
detect (CD) signal (that is, the CD
is not active).
The line is down or is not
connected on the far end.
Cabling is faulty or incorrect.
Hardware failure has occurred in
the channel service unit/data
service unit (CSU/DSU).
Troubleshooting the Serial SPAs
Solution
1 Check the CD LEDs to see
whether the CD is active, or
insert a breakout box on the
line to check for the CD signal.
2 Verify that you are using the
proper cable (see your
hardware installation
documentation).
3 Insert a breakout box and check
all control leads.
4 Contact your leased-line or
other carrier service to see
whether there is a problem.
5 Swap faulty parts.
6 If you suspect faulty router
hardware, change the serial line
to another port. If the
connection comes up, the
previously connected interface
has a problem.
OL-14127-17