Automatic DCID
assignment should be permanently configured. However, if you need to remove the
feature, use the
no or
default
commands.
 Note |
The
no or
default form
of the command is not written to startup-config file.
|
In this case, the
DCIDs are retained as computed for all channels, and are not set to the
defaults of the channels. Save the configuration containing the newly-assigned
DCIDs to the startup-config file by using the
write
memory command.
When you enable automatic DCID assignment, any DCID
conflict arising due to adding a channel in a fiber-node is resolved
automatically.
Restriction:
-
After
running the
cable
downstream-channel-id
automatic command in the configuration, manually
editing the configuration file in an editor to add RF channels to the fiber
nodes could cause DCID conflicts. The feature assumes all channels in fiber
nodes have unique automatic DCIDs in global configuration mode. If the
configuration is manually edited and the feature does not verify the unique
DCIDs, the DCIDs of the newly-added channels may conflict with those of the
existing channels. To fix any DCID conflicts, undo and re-apply the global
automatic DCID configuration.
 Note |
Re-applying global automatic DCID configuration is a disruptive
operation.
|
To avoid
DCID conflicts, edit the configuration to configure the fiber nodes, then run
the
cable
downstream-channel-id
automatic command so all channels have unique
automatic DCIDs.
Make
additions to the fiber nodes on the Cisco uBR10012 router command line
interface with the automatic DCID configured.
- The
cable
downstream-channel-id
automatic command can be configured only on the
Cisco uBR10012 universal broadband router.
- The
cable
downstream-channel-id
automatic command should not be manually edited in
to the startup-config file, since it does not guarantee unique DCIDs for
channels in the fiber node.
| Command or Action | Purpose |
---|
Step 1 | enable
Example:
Router> enable
|
Enables
privileged EXEC mode.
- Enter your password if
prompted.
|
Step 2 | configure
terminal
Example:
Router# configure terminal
|
Enters global
configuration mode.
|
Step 3 | cable downstream-channel-id automatic
Example:
Router(config)# cable downstream-channel-id automatic
|
Specifies
automatic assignment of the DCIDs by the Cisco CMTS.
|
Example
This example
displays the restriction on manually editing configurations:
Router# show run | include automatic
cable downstream-channel-id automatic
Router# show cable fiber-node 3
---------------------------------------------------------------------------------
Fiber-Node 3
Channel(s) : downstream Modular-Cable 1/1/0: 0
Channel ID(s): 3
Channel : downstream Cable 6/1/0
Channel ID : 1
upstream Cable 6/1: 0-3
FN Config Status: Configured (status flags = 0x01)
MDD Status: Valid
router#
If you manually edit the startup-config file in an
editor to add a downstream channel, for example, 5/0/0 rf-channel 0, from a
newly-added line card, 5/0, it causes a conflict.
Router> configure terminal
Router# cable fiber-node 3
Router# downstream Modular-Cable 5/0/0 rf-channel 0
If this downstream channel is added on the Cisco
uBR10012 router, the automatic DCID assignment feature automatically resolves
it. However, since the startup-config file was manually edited to add the
downstream channel, the automatic DCID assignment feature is unable to resolve
it. This causes a DCID conflict when the edited startup-config file is loaded
on the Cisco uBR10012 router and invalidates the fiber node.
down Modular-Cable 5/0/0 rf-channel 0
Fiber node 3 is invalid for:
DS frequency is not unique.
DS channel id is not unique.
Warning: D3.0 CMs cannot get w-online with an invalid fiber-node.
router#
What to Do Next
Run the
show
cable
fibernode command to view DCIDs assigned to all
the channels in the fiber node.
Router# show cable fiber-node 5
Fiber-Node Config Status
Fiber-Node 5
Description: Interface c5/0/4
Channels DOCSIS Channel-IDs
------------------------------------------------------
Modular-Cable 3/3/0: 1-3 2,3,4
Cable 5/0/4 1
FN Config Status: Configured (status flags = 0x01)
MDD Status: Valid