Chapter 17: IP Packet Filters, Subscriber Management
STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
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3.
Finally, if there are no TLV or per-interface IP packet filters configured, the system-wide parameters specifying default
filter groups are applied.
Multiple Subinterface Environment
In a multiple subinterface environment, modems on each subinterface could be assigned modem configuration files that
specify filter groups that are specific for that subinterface.
This capability exists today in any system compliant with DOCSIS® 1.1. The provisioning system determines on which
subinterface each modem resides, a necessary step for assigning the IP address. It then uses the modem to which the CPE
is attached to determine the CPE’s subinterface.
The ability to assign default IP filter groups based on the subinterface and derived from the IP address of the CM or CPE is
an enhancement of the per-subinterface IP packet filtering feature. If per-subinterface filter groups have been assigned,
they are used in place of the system-wide default filter groups. However, the per-subinterface filter groups are not used if
filter groups are assigned in the modem configuration file.
For CPEs, the assignment of these new subinterface level filter group parameters would take place when an IP address is
assigned by DHCP, in addition to when the CPE is learned, since CPE assignment to a subinterface would take place when it
gets its IP address. If a CPE doesn't have an IP address when it is first learned (i.e., it is doing DHCP), it initially uses the CPE
filters associated with the modem's subinterface. Once it obtains an IP address, the CPE's filter group will change if the CPE
is in a different subinterface than the modem and that subinterface has default values that are different from the
modem’s.
Recommendations for Using Per-Subinterface Filter Groups
blah blah
Default Filter CLI Examples
The following CLI commands assign default filters for a subinterface:
configure interface cable-mac 1.0 cable submgmt default filter-group cm downstream <group>
configure interface cable-mac 1.0 cable submgmt default filter-group cm upstream <group>
configure interface cable-mac 1.0 cable submgmt default filter-group host downstream <group>
configure interface cable-mac 1.0 cable submgmt default filter-group host upstream <group>