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Cisco Broadband Cable Command Reference Guide
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Chapter 2 Cisco CMTS Configuration Commands
cable tftp-enforce
Note
In the above situation, cable modems that do not download a DOCSIS configuration file are marked as
“offline” instead of “reject(c)” by the
show cable modem
command. The console still displays the
%UBR10000-4-REGISTRATION_BEFORE_TFTP error message, however, to allow you to identify
these cable modems as TFTP violators.
Examples
The following example shows how to enforce TFTP downloads for all of the cable modems on cable
interface 3/0. These cable modems must attempt a TFTP download of the DOCSIS configuration file
through the cable interface with the Cisco CMTS. If they do not, they are not allowed to register or come
online, and they are marked as having either a registration error—reject(c)—in the
show cable modem
command.
Note
The initial version of this feature marked CMs that failed the TFTP check as having a Message Integrity
Check (MIC) failure—reject(m). The command was changed to show reject(c) in Cisco IOS Release
12.2(8)BC2 and Release 12.1(19)EC.
Router#
configure terminal
Router(config)#
interface cable 3/0
Router(config-if)#
cable tftp-enforce
Router(config-if)#
exit
Router(config)#
Router#
show cable modems
Interface Prim Online Timing Rec QoS CPE IP address MAC address
Sid State Offset Power
Cable3/0/U1 1 online(pt) 2734 0.50 5 0 10.1.1.38 00ff.fffa.0a35
Cable3/0/U0 2 online(pt) 2729 0.25 5 0 10.1.1.50 00ff.ff07.382f
Cable3/0/U0 3 init(i) 2732 0.25 2 0 10.1.1.48 00ff.ff03.307d
Cable3/0/U1 4 online(pt) 2737 0.75 5 0 10.1.1.34 00ff.ff59.4477
Cable3/0/U1 5 reject(m) 2215 0.25 2 0 10.1.1.47 00ff.ff66.12fb
Router#
Note
DOCSIS-compliant cable modems that are rejected with a MIC failure go into the offline state for a short
period of time and then retry the registration process.
The
debug cable registration
command can be used to display additional information:
Router#
debug cable interface c3/0 verbose
Router#
debug cable registration
CMTS registration debugging is on
Jun 6 23:27:15.859: Registration request from 00ff.ff66.12fb, SID 7 on Cable3/0/U1
Jun 6 23:27:15.859: Found a network access control parameter: Ok
Jun 6 23:27:15.859: Found a class of service block: Ok
Jun 6 23:27:15.859: Found Baseline Privacy config: Ok
Jun 6 23:27:15.859: Found Max CPE: Ok
Jun 6 23:27:15.859: Found CM MIC: Ok
Jun 6 23:27:15.859: Found CMTS MIC: Ok
Jun 6 23:27:15.859: Found modem ip: Ok
Jun 6 23:27:15.859: Found modem capabilities: Ok
Jun 6 23:27:15.859: Finished parsing REG Request
Jun 6 23:27:15.859: Cable Modem sent Registration Request without attempting required
TFTP
22:33:21 %UBR7200-4-REGISTRATION_BEFORE_TFTP: Registration request unexpected: