Activating Cable Modem Upstream Address Verification - Cisco 7246VXR - uBR Router Software Configuration Manual

Activating Cable Modem Upstream Address Verification

Activating Cable Modem Upstream Address Verification
CM upstream address verification ensures that only CMs that have received Dynamic Host
Configuration Protocol (DHCP) leases through the Cisco uBR7200 series CMTS can access the HFC
network. The Cisco uBR7200 series CMTS discards all packets received from or for hosts that have not
received Dynamic Host Configuration Protocol (DHCP)-assigned addresses. The default setting is "off"
(CM upstream address verification is deactivated).
To activate or deactivate CM upstream verification, use the following command in the cable interface
configuration mode:
Command
cable source-verify [dhcp]
no cable source-verify
Verifying Cable Modem Upstream Address Verification
To verify that CM upstream verification has been activated or deactivated, enter the
more system:running-config command and look for the
cable interface configuration information. If CM upstream verification has been deactivated, it does not
appear in this output. If CM upstream verification has been activated, it appears in this output as
cable source-verify
Router# more system:running-config
Building configuration...
Current configuration:
!
interface Cable5/0
ip address 1.1.1.1 255.255.255.0
no keepalive
cable source-verify
cable insertion-interval 2000
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable downstream symbol-rate 5056941
cable upstream 0 frequency 15008000
cable upstream 0 fec
cable upstream 0 scrambler
no cable upstream 0 shutdown
!
Be sure that you enter the correct slot and port number when you enter the cable interface configuration
Tip
mode.
If the Cisco uBR7200 series router is reloaded or the Address Resolution Protocol (ARP) table is
Note
cleared, all hosts on the network are forced to release and renew their IP addresses. Some systems might
require restarting if the IP protocol stack is unable to renew using a broadcast IP address.
Cisco uBR7200 Series Universal Broadband Router Software Configuration Guide
5-4
Chapter 5
Purpose
Activates CM upstream verification. The dhcp option specifies that
queries be sent to verify unknown IP addresses in upstream data
packets.
Returns to the default upstream verification state.
, as shown in this command output excerpt:
Managing Cable Modems on the Hybrid Fiber-Coaxial Network
no cable source-verify
notation in the
OL-2239-03