Cisco Broadband Cable Command Reference Guide

Chapter 2 Cisco Cable Modem Termination System Commands
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Cisco Broadband Cable Command Reference Guide
cable filter group
When matching the source or destination addresses, the filter ANDs the mask value with the filter’s
corresponding IP address. The filter then ANDs the mask with the packet’s actual IP address and
compares the two values. If they are the same, the filter matches the packet.
For example, if you specify a src-ip of 192.168.100.0 and a src-mask of 255.255.255.0, the filter
matches all packets that have a source IP address in the range of 192.168.100.0 through
192.168.100.255. Use a mask value of 0.0.0.0 (default) to match all IP addresses. Use a mask value of
255.255.255.255 to match one specific IP address.
Similarly, when comparing TOS values, the filter ANDs the tos-mask parameter with the tos-value
parameter and compares it to the result of ANDing the tos-mask parameter with the packet’s actual TOS
value. If the two values are the same, the filter matches the packet.
Tip See the description of the docsSubMgtPktFilterTable table in this MIB for further information.
Note The DOCS-SUBMGT-MIB MIB is supported only on Cisco IOS Release 12.2(8)BC2 and later 12.2 BC
releases.
Examples The following example shows a filter group being defined that drops packets with a source IP address of
7.7.7.7 and a destination IP address of 8.8.8.8, and a source port number of 2000 and a destination port
number of 3000. All protocol types and ToS and TCP flag values are matched:
Router# configure terminal
Router(config)# cable filter group 10 index 10 src-ip 7.7.7.7
Router(config)# cable filter group 10 index 10 src-mask 255.255.0.0
Router(config)# cable filter group 10 index 10 dest-ip 8.8.8.8
Router(config)# cable filter group 10 index 10 dest-mask 255.255.0.0
Router(config)# cable filter group 10 index 10 ip-proto 256
Router(config)# cable filter group 10 index 10 src-port 2000
Router(config)# cable filter group 10 index 10 dest-port 3000
Router(config)# cable filter group 10 index 10 tcp-flags 0 0
Router(config)#
Related Commands Command Description
show cable filter Displays the DOCSIS 1.1 filter groups that are currently defined.
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