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Cisco uBR10012 Universal Broadband Router Software Configuration Guide
OL-1520-08
Chapter1 Overview of CiscouBR10012 Universal Broadband Router Software Supported Software Features for the CiscouBR10012 Router
To enable packets from trusted source MAC addresses in DHCP, use the cable trust command in global
configuration mode. To remove a trusted MAC address from the MAC exclusion list, use the no form of
this command. Removing a MAC address from the exclusion list subjects all packets from that source
to standard DHCP source verification.
cable trust mac-address
no cable trust mac-address
Syntax Description
Usage Guidelines This command and capability are only supported in circumstances in which the Cable Source Verify
feature is first enabled on the Cisco CMTS.
When this feature is enabled in addition to cable source verify, a packet’s source must belong to the
MAC Exclude list on the Cisco CMTS. If the packet succeeds this exclusionary check, then the source
IP address is verified against Address Resolution Protocol (ARP) tables as per normal and previously
supported source verification checks. The service ID (SID) and the source IP address of the packet must
match those in the ARP host database on the Cisco CMTS. If the packet check succeeds, the packet is
allowed to pass. Rejected packets are discarded in either of these two checks.
Any trusted source MAC address in the optional exclusion list may be removed at any time. Removal of
a MAC address returns previously trusted packets to non-trusted status, and subjects all packets to
standard source verification checks on the Cisco CMTS.
For additional information about the enhanced Cable Source Verify DHCP feature, and general
guidelines for its use, refer to the following documents on Cisco.com:
•IP Address Verification for the Cisco uBR7200 Series Cable Router
http://www.cisco.com/en/US/products/sw/iosswrel/ps1830/products_feature_guide09186a0080087b55.html
•Filtering Cable DHCP Lease Queries
http://www.cisco.com/en/US/products/hw/cable/ps2217/products_feature_guide09186a008021b8fb.html
•Cisco Broadband Cable Command Reference Guide
http://www.cisco.com/en/US/products/hw/cable/ps2217/products_command_reference_book0918
6a0080108e88.html
•CABLE SECURITY, Cable Source-Verify and IP Address Security, White Paper
http://www.cisco.com/en/US/tech/tk86/tk803/technologies_tech_note09186a00800a7828.shtml
Integrated DHCP Server
This network management feature simplifies provisioning, offering an integrated Dynamic Host
Configuration Protocol server. For information about configuring DHCP, ToD, or TFTP services, refer
to the chapter titled “Configuring DHCP, ToD, and TFTP Services” in the Cisco Cable Modem
Termination System Feature Guide on Cisco.com.
mac-address The MAC address of a trusted DHCP source, and from which packets will
not be subject to standard DHCP source verification.