Cisco Broadband Cable Command Reference Guide

Chapter 4 Cisco Cable Modem Termination System Debugging Commands
debug cable encap
OL-1581-05
Cisco Broadband Cable Command Reference Guide
debug cable encap
To enable debugging of encapsulated packets that are transmitted over the cable interface, use the debug
cable encap command in privileged EXEC mode. To disable debugging output, use the no form of the
command.
debug cable encap
no debug cable encap
Syntax Description This command has no arguments or keywords.
Command Modes Privileged EXEC
Command History
Release Modification
12.2(11)BC3 This command was introduced.
Usage Guidelines The debug cable encap command displays debugging messages about the following types of
encapsulated packets:
Debug messages prefixed with ENCAPSTR display information about CEF adjacency operations.
Debug messages prefixed with VENCAP display information about MAC-layer encapsulation for
switched packets (such as PPPoE and IP packets).
The debug commands are primarily intended for use in controlled test and troubleshooting situations
with a limited volume of traffic. In particular, avoid using the debug cable encap command on an
interface with a significant number of CMs, because the resulting volume of debug output could impact
system performance. Cisco recommends that when you use the debug cable encap command, you limit
its output to a particular interface or CM, using the debug cable interface or debug cable mac-address
commands.
Examples The following shows typical output for the debug cable encap command. Messages are shown for both
CEF adjacency and MAC-layer encapsulation events:
Router# debug cable encap
CMTS encap debugging is on
Router# clear adjacency
ENCAPSTR hwidb Cable3/1 idb Cable3/1.1 mac 0020.4072.7418 ipaddr 31.0.0.2 linktype 7
ENCAPSTR 0020.4072.7418 SID 2 STR 00000000800200204072741800D0582770540800
Router# ping 31.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 31.0.0.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/5/8 ms
4-21