Installation guide

34
Release Notes for Cisco uBR7200 Series for Cisco IOS Release 12.1 T
78-10643-04 Rev. B0
New and Changed Information
• show cable bundle number forwarding table — Displays all the currently known cable devices in
the bundle.
Administrators can create subinterfaces on cable interfaces or cable interface bundles to support VPN.
Each subinterface can be assigned to a specific pool of IP addresses, mapping that subinterface to a
particular VPN customer network. A Generic Routing Encapsulation (GRE) tunnel can also be created
between the Cisco uBR7200 series router and the router that serves as the VPN customer gateway.
When a cable modem registers with the Cisco uBR7200 Series Universal Broadband Router, its IP
address is used to identify the subinterface being used by the cable modem; this information is used to
associate the Service Identifier (SID) assigned to the modem to that subinterface (and thus the VPN
customer network).
Note Cisco IOS Release 12.1(1a)T1 and Release 12.1(3)T do not include MPLS support as part
of its VPN support on the cable subinterfaces. Cisco IOS Release 12.1(2)T and Release
12.1(5)T and higher releases do support MPLS over VPN.
A subinterface can be created on any cable interface that is not part of a cable interface bundle. A
subinterface can also be created on the master cable interface bundle; subinterfaces cannot be created
on non master bundles.
Subinterfaces support the following existing cable interface commands:
• cable arp
• cable dhcp-giaddr
• cable helper-address
• cable ip-broadcast-echo
• cable ip-multicast-echo cable proxy-arp
• cable source-verify
Caution Configure an IP address on the master interface only. An attempt to add an interface to a
bundle will be rejected if an IP address is configured and the interface is not specified as
a master interface.
When bundling cable interfaces, only the interface configured to be the bundle master is
allowed to have subinterfaces. An interface that has subinterface(s) defined over it will not
be allowed to be part of a bundle.
MIB objects on cable interface bundles are not supported as of the date of this publication.
For more information on cable bundling, see the chapter Understanding System Operations of the
Cisco uBR7200 Series Software Configuration Guide.
Upstream Address Verification Enhancement
This feature prevents the spoofing of IP addresses by verifying that each upstream data packet comes
from the cable modem known to be associated with the source IP address in the packet. The cable
source-verify [ dhcp ] cable interface command specifies that DHCP lease query requests are sent to
verify any unknown source IP address found in upstream data packets. This feature requires a DHCP
server that supports the new LEASEQUERY message type.