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Cisco Broadband Cable Command Reference Guide
OL-1581-08
Chapter 2 Cisco CMTS Configuration Commands
option
Tip
The Institute of Electrical and Electronics Engineers (IEEE) is the official issuer of OUI values. The
IEEE OUI web site is at
http://standards.ieee.org/regauth/oui/index.shtml
.
Example of Constructing an Option 43 Command
For example, to create a vendor-specific option that downloads a Cisco IOS configuration file, you would
create a hexadecimal data string that first contains suboption 8, to specify the vendor ID in TLV format.
You would then add the hexadecimal string that contains suboption 128, to specify the filename for the
configuration file to be downloaded, in TLV format.
The TLV for the Cisco vendor ID would be
08:03:00:00:0C
, where
08
is the suboption type,
03
is the
length, and
00:00:0C
is the Cisco OUI vendor ID. If the Cisco IOS filename is
ios.cfg
, the second TLV
would be
80:07:69:6F:73:2E:63:66:67
, where
80
is the suboption type (128 decimal),
07
is the length
of the data, and the data is the filename expressed in hexadecimal ASCII values.
The complete
hex
data string would be
08:03:00:00:0C:80:07:69:6F:73:2E:63:66:67
. The complete
command would be
option 43 hex 08:03:00:00:0C:80:07:69:6F:73:2E:63:66:67
.
Note
When using the
option 43
command, you must manually calculate the length value for each TLV that
you specify in the
hex
data string. However, you do not have to calculate the length for entire
option 43
command, because that is calculated automatically by the CMTS.
Caution
Be certain that you have correctly entered the TLV data when using the
hex
option. Incorrectly entered
data could cause CMs to reset, go offline, or hang, requiring a power cycle before being able to continue.
Tip
Use the
instance
keyword to construct a DOCSIS configuration file that contains multiple
option 43
commands. The multiple commands can be for the same vendor or for different vendors. Specifying
multiple commands for the same vendor is necessary when the total length of all data is greater than 254
bytes, which is the maximum length of the
hex
data field.
Examples
The following example shows how to specify a static downstream frequency for a Cisco uBR905,
Cisco uBR924, Cisco uBR925, or Cisco CVA, using the
option 43
command to specify Cisco vendor-
specific option 1.
router(config)#
cable config-file statfreq.cm
router(config-file)#
option 43 hex 08:03:00:00:0C:01:04:05:7F:9F:90
router(config-file)#
exit
router(config)#
The hexadecimal data shown in this command consists of the two TLVs shown in
Table 2-20
:
Table 2-20 TLV Values for Sample Option 43 Command
Type
Length
Value
TLV 1—Vendor ID, Suboption 8
08
03
00:00:0C (the ID for Cisco cable equipment)