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Cisco uBR10012 Universal Broadband Router Software Configuration Guide
OL-1520-05
Chapter 1 Overview of Cisco uBR10012 Universal Broadband Router Software
Supported Software Features for the Cisco uBR10012 Router
Refer to
Chapter 4, “Managing Cable Modems on the Hybrid Fiber-Coaxial Network”
to configure
address verification.
CM Transmission Burst Size
The Cisco uBR10012 router allows CMs to register with a maximum transmission burst size up to 2000
bytes. This applies to DOCSIS 1.0 and 1.1 CMs that are configured with concatenation and no IP
fragmentation.
For additional information about configuring dynamic upstream modulation and modulation profiles,
refer to one or more of these documents on Cisco.com:
Cisco Cable Modem Termination System Feature Guide
Cisco uBR7200 Series Dynamic Upstream Modulation
at
http://www.cisco.com/en/US/docs/cable/cmts/feature/spec_mgt.html
Dynamic or Mobile Host Support
The
cable source-verify
command allows the CMTS administrator to bring up a PC behind one CM,
then move it to another CM. This adds information for the hosts involved in host tables. To prevent
security breaches, this feature supports pinging the host using the old SID to verify that it has indeed
been moved. The security applies to upstream and downstream configuration.
Note
The
no cable arp
command should be configured in the CMTS to prevent it from sending ARP requests.
The
no cable arp
command prevents the CMTS from sending an arp downstream to CPE hosts or to
devices behind CMs requesting an IP/MAC address association. If the CMTS already knows the
association, or is able to learn it in some other manner, IP packets are forwarded. Otherwise, if the
destination is unknown, the packets are dropped.
Devices on a CM network may share a large subnet, but cannot communicate with each other without
first going through the CMTS. The
no cable proxy arp
command prevents the CMTS from replying to
arp requests for hosts on the same subnet, and thus prevents peer to peer communication between
subscribers behind CMs.
For additional command information, refer to the
Cisco CMTS IOS Cable Command Reference Guide
on Cisco.com.
Dynamic Shared Secret (DMIC) with OUI Exclusion
Cisco IOS Release 12.3(9a)BC introduces the option of
excluding
the Organizational Unique Identifiers
(OUIs) from being subjected to the DMIC check. The new
cable dynamic-secret exclude
command
allow specific cable modems to be excluded from the Dynamic Shared Secret feature on the following
Cisco CMTS platforms:
•
Cisco uBR7246VXR universal broadband router
•
Cisco uBR10012 universal broadband router
The Dynamic Shared Secret feature automatically creates a unique DOCSIS shared secret on a per-modem
basis, creating a one-time use DOCSIS configuration file that is valid only for the current session. This
ensures that a DOCSIS configuration file that has been downloaded for one cable modem can never be used
by any other modem, nor can the same modem reuse this configuration file at a later time.
Command
Description
cable source-verify dhcp
Configures the DHCP server to verify addresses.
