Virtual Interface Bundling

Virtual Interface Bundling allows supports combining multiple cable interfaces in a Cisco cBR series router into a single logical bundle, so as to conserve IP address space and simplify network management.

Finding Feature Information

Your software release may not support all the features that are documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. The Feature Information Table at the end of this document provides information about the documented features and lists the releases in which each feature is supported.

Contents

Hardware Compatibility Matrix for the Cisco cBR Series Routers


Note
The hardware components that are introduced in a given Cisco IOS-XE Release are supported in all subsequent releases unless otherwise specified.
Table 1. Hardware Compatibility Matrix for the Cisco cBR Series Routers

Cisco CMTS Platform

Processor Engine

Interface Cards

Cisco cBR-8 Converged Broadband Router

Cisco IOS-XE Release 16.5.1 and Later Releases

Cisco cBR-8 Supervisor:

  • PID—CBR-SUP-250G

  • PID—CBR-CCAP-SUP-160G

  • PID—CBR-CCAP-SUP-60G

  • PID—CBR-SUP-8X10G-PIC

Cisco IOS-XE Release 16.5.1 and Later Releases

Cisco cBR-8 CCAP Line Cards:

  • PID—CBR-LC-8D30-16U30

  • PID—CBR-LC-8D31-16U30

  • PID—CBR-RF-PIC

  • PID—CBR-RF-PROT-PIC

  • PID—CBR-CCAP-LC-40G

  • PID—CBR-CCAP-LC-40G-R

Cisco cBR-8 Downstream PHY Modules:

  • PID—CBR-D30-DS-MOD

  • PID—CBR-D31-DS-MOD

Cisco cBR-8 Upstream PHY Modules:

  • PID—CBR-D30-US-MOD

  • PID—CBR-D31-US-MOD

Information About Virtual Interface Bundling

This section contains the following:

Overview of Virtual Interface Bundling


Note

All cable bundles are automatically converted and configured to virtual interface bundles. Any standalone cable interfaces must be manually configured to be in a virtual bundle to operate properly.

Virtual interface bundling supports the following:

  • Virtual interface bundling uses bundle interface and bundle members instead of primary or secondary interfaces.

  • A virtual bundle interface is virtually defined, as with IP loopback addresses.

  • Virtual interface bundling supports bundle information in multiple show commands.

  • The CISCO-DOCS-EXT-MIB is updated for cable helper-address and IPv6 DHCP relay configurations.

Virtual interface bundling prevents loss of connectivity on physical interfaces should there be a failure, problematic online insertion and removal (OIR) of one line card in the bundle, or erroneous removal of configuration on the primary interface.

Virtual interface bundling supports and governs the following Layer 3 settings for the bundle member interfaces:

  • IP address

  • IP helper-address

  • source-verify and lease-timer functions

  • cable dhcp-giaddr (The giaddr field is set to the IP address of the DHCP client.)

  • Protocol Independent Multicast (PIM)

  • Access control lists (ACLs)

  • Sub-interfaces

  • IPv6

  • 1982 bytes layer 3 MTU.


    Note

    In case customer wants to test 1982 bytes MTU by issuing a ping from CMTS to DOCSIS 3.1 modem, cable mtu-override command needs to be configured. After the test, please remove this configuration using no cable mtu-override command. By default, there is no cable mtu-override configured in bundle interface.


Note

This virtual interface for the bundle should always remain on (enabled with no shutdown ).

Guidelines for Virtual Interface Bundling

The following guidelines describe virtual interface bundling:

  • Initial configuration of the first virtual bundle member automatically creates a virtual bundle interface.

  • All cable bundles are automatically converted and configured to be in a virtual bundle after loading the software image.

  • Standalone cable interfaces must be manually configured to be in a virtual bundle to operate properly.

  • The virtual bundle interface accumulates the counters from members; counters on member links are not cleared when they are added to the bundle. If a bundle-only counter is desired, clear the bundle counter on the members before adding them to the bundle, or before loading the image.

  • This feature supports a maximum of 40 virtual interface bundles, with the numeric range from 1 to 255.

  • The virtual bundle interface remains configured unless specifically deleted, even if all members in the bundle are deleted.

  • This feature supports subinterfaces on the virtual bundle interface.

  • Bundle-aware configurations are supported on the virtual bundle interface.

  • Bundle-unaware configurations are supported on each bundle member.

  • While creating the virtual bundle interface, if the bundle interface existed in earlier Cisco IOS releases, then the earlier cable configurations re-appear after upgrade.

  • When using sub-bundle, all layer 3 configurations must be configured on sub-bundle, instead of main bundle.

Virtual Interface Bundle-aware and Bundle-unaware Support

Virtual interface bundling uses two configurations: the virtual bundle itself, and the interfaces in that virtual bundle, known as bundle members . The virtual interface bundle and bundle members are either aware of the bundle, or unaware of the bundle, as follows.

  • Bundle-aware features are maintained on the virtual bundle . These include:
    • IP Address
    • IP helper, cable helper
    • Dhcp-giaddr
    • Sub-interface
    • Source verify
    • Lease-query
    • Address Resolution Protocol (Cable ARP filtering, which also bundles cable interfaces, and Proxy ARP)
    • Cable match
    • Access Control Lists (ACLs)
    • Protocol Independent Multicast (PIM)
    • Cable Intercept
  • Bundle-unaware features are maintained on the bundle members . These include:
    • DS/US configurations
    • HCCP redundancy
    • Load balancing
    • DMIC, tftp-enforce, shared-secret
    • Spectrum management
    • Admission control
    • Intercept

Configuring Virtual Interface Bundling

To enable virtual interface bundling, and to reconfigure interface information on the Cisco CMTS as required, you first configure the virtual interface bundle, then add additional bundle members for the specified virtual bundle. Perform these steps on each interface, as needed for all virtual interface bundles.

Procedure

  Command or Action Purpose

Step 1

enable

Example:


Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Router# configure terminal

Enters global configuration mode.

Step 3

interface bundle n

Example:


Router(config-if)# interface bundle 1

Adds the selected interface to the virtual bundle. If this is the first interface on which the virtual bundle is configured, this command enables the bundle on the specified interface.

As many as 40 virtual interface bundles can be configured on the Cisco CMTS. Numeric identifiers may range from 1 to 255.

Step 4

ip address address mask

Example:


Router(config-if)# ip address 7.7.7.7 255.255.255.0

Use as needed after Cisco IOS upgrade.

Configures the IP address for the specified interface and virtual bundle.

Step 5

cable helper-address address [cable-modem | host | mta | ps | stb]

Example:


Router(config-if)# cable helper-address 10.10.10.13

(Optional) Specifies the IPv4 DHCP server address.

Step 6

cable dhcp-giaddr {primary | policy [host | stb | mta | ps | strict]}

Example:

Router(config-if)# cable dhcp-giaddr policy host

Sets the DHCP GIADDR field for DHCP request packets.

Step 7

cable source-verify dhcp

Example:

Router(config-if)# cable source-verify dhcp

(Optional) Ensures that the Cisco CMTS allows network access only to those IP addresses that DCHP servers issued to devices on this cable interface. The Cisco CMTS examines the DHCP packets that pass through the cable interfaces to build a database of which IP addresses are valid on which interface. Drops traffic from all devices with unknown IP addresses, but the Cisco CMTS also sends a query to the DHCP servers for any information about the device. If a DHCP server informs the Cisco CMTS that the device has a valid IP address, the CMTS then allows the device on the network.

Step 8

no cable arp

Example:

Router(config-if)# no cable arp

(Optional) Blocks the static IPv4 CPE from coming online. Also blocks Address Resolution Protocol (ARP) process destined to devices on the cable network.

Note

 

Use this command, together with the cable source-verify dhcp command, to block certain types of scanning attacks that attempt to cause denial of service (DoS) on the Cisco CMTS.

Step 9

exit

Example:

Router(config-if)# exit

Exits the interface configuration mode and enters global configuration mode.

Step 10

interface cable slot /subslot/port

Example:


Router(config)# interface cable 3/0/0

Enters interface configuration mode for the selected interface, on which virtual interface bundling is to be enabled.

Step 11

cable bundle n

Example:


Router(config-if)# cable bundle 1

Configures a cable interface to belong to an interface bundle, where n is the bundle number.

Step 12

no cable upstream n shut

Example:


Router(config-if)# no cable upstream 4 shut

Use as needed after Cisco IOS upgrade.

The cable interface must be enabled using the no shutdown command for the specified cable interface.

n —Specifies the cable interface to enable for the virtual bundle.

Step 13

end

Example:


Router(config-if)# end

Returns to privileged EXEC mode.

What to do next

To remove a virtual bundle from the interface, use the no interface bundle command in interface configuration mode, where n specifies the bundle identifier:

no interface bundle n

If you remove a member from a bundle, the bundle remains on the interface (even if empty) until the bundle itself is specifically removed.

For more information on configuring IPv6 parameters for bundle interface, see IPv6 on Cable feature guide.

Verfiying the Virtual Interface Bundling Configuration

  • show ip interface brief —Displays the summary of interfaces.

    Following is a sample output of this command: 

    Router# show ip interface brief

Interface              IP-Address      OK? Method Status                Protocol
Cable3/0/0             Bundle1         YES unset  up                    up
GigabitEthernet0       10.86.3.175     YES NVRAM  administratively down down
Bundle1                100.1.2.1       YES manual up                    up
Bundle2                100.1.3.1       YES NVRAM  up                    up
Dti4/1/0               unassigned      YES unset  administratively down down
Dti5/1/0               unassigned      YES unset  administratively down down
Dti4/1/1               unassigned      YES unset  administratively down down
Dti5/1/1               unassigned      YES unset  administratively down down
Loopback1              1.2.3.4         YES NVRAM  up                    up
Tunnel0                unassigned      YES unset  up                    up

  • show running-config interface bundle n —Displays the information about the specified bundle.

    Following is a sample output of this command: 

    Router# show running-config interface Bundle 1

Current configuration : 696 bytes
!
interface Bundle2
 ip address 100.1.3.1 255.255.255.0
 no cable nd
 cable arp filter request-send 3 2
 cable arp filter reply-accept 3 2
 no cable arp
 cable ipv6 source-verify dhcp
 cable source-verify dhcp
 cable dhcp-giaddr primary
 cable helper-address 10.10.0.53
 ipv6 address 2001:420:3800:910::1/64
 ipv6 enable
 ipv6 nd reachable-time 3600000
 ipv6 nd cache expire 65536
 ipv6 nd managed-config-flag
 ipv6 nd other-config-flag
 ipv6 nd ra interval msec 2000
 no ipv6 redirects
 ipv6 dhcp relay destination 2001:420:3800:800:250:56FF:FEB2:F11D
 ipv6 dhcp relay destination vrf vrfa 2001:420:3800:800:250:56FF:FEB2:F11D
 ipv6 dhcp relay source-interface Bundle2
 arp timeout 2147483

  • show ip interface brief | include bundle —Displays the bundle interface information.

    Following is a sample output of this command: 

    Router# show ip interface brief | include Bundle

Bundle1 unassigned YES unset up up
Bundle1.1 100.1.2.1 YES NVRAM up up
Bundle2 100.1.3.1 YES NVRAM up up

  • show running-config interface bundle n.n —Displays the subinterface information for the specified bundle.

    Following is a sample output of this command: 

    Router# show running-config interface bundle 1.1

Current configuration : 1415 bytes
!
interface Bundle1.1
ip address 100.1.2.1 255.255.255.0
ip pim sparse-mode
ip rip send version 2
ip rip receive version 2
ip rip authentication mode md5
ip rip authentication key-chain ubr-rip
ip igmp static-group 239.1.4.1 source 115.255.0.100
ip igmp static-group 239.1.3.1 source 115.255.0.100
ip igmp static-group 239.1.2.1 source 115.255.0.100
ip igmp static-group 232.1.4.1 source 115.255.0.100
ip igmp static-group 232.1.3.1 source 115.255.0.100
ip igmp static-group 232.1.2.1 source 115.255.0.100
ip igmp static-group 232.1.1.1 source 115.255.0.100
ip igmp static-group 230.1.4.1
ip igmp static-group 230.1.3.1
ip igmp static-group 230.1.2.1
ip igmp static-group 224.1.4.1
ip igmp static-group 224.1.3.1
ip igmp static-group 224.1.2.1
ip igmp static-group 224.1.1.1
ip igmp version 3
ip igmp query-interval 20
no cable arp
cable ipv6 source-verify dhcp
cable source-verify dhcp
cable dhcp-giaddr primary
cable helper-address 10.10.0.53
ipv6 address 2001:420:3800:909::1/64
ipv6 enable
ipv6 nd reachable-time 3600000
ipv6 nd cache expire 65536
ipv6 nd prefix default no-advertise
ipv6 nd managed-config-flag
ipv6 nd other-config-flag
ipv6 nd ra interval msec 2000
no ipv6 redirects
ipv6 dhcp relay destination 2001:420:3800:800:250:56FF:FEB2:F11D link-address 2001:420:3800:909::1
ipv6 dhcp relay source-interface Bundle1
ipv6 rip CST enable
arp timeout 2147483

Additional References

Related Documents

Related Topic

Document Title

CMTS Command Reference

Cisco IOS CMTS Cable Command Reference Guide

Standards and RFCs

Standards

Title

SP-RFIv1.1-I09-020830

Data-over-Cable Service Interface Specifications Radio Frequency Interface Specification, version 1.1

SP-RFIv2.0-I03-021218

Data-over-Cable Service Interface Specifications Radio Frequency Interface Specification, version 2.0

SP-OSSIv2.0-I03-021218

Data-over-Cable Service Interface Specifications Operations Support System Interface Specification, version 2.0

SP-BPI+-I09-020830

Data-over-Cable Service Interface Specifications Baseline Privacy Plus Interface Specification, version 2.0

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Feature Information for Virtual Interface Bundling

Use Cisco Feature Navigator to find information about the platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to the www.cisco.com/go/cfn link. An account on the Cisco.com page is not required.


Note

The following table lists the software release in which a given feature is introduced. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Table 2. Feature Information for Virtual Interface Bundling

Feature Name

Releases

Feature Information

Virtual interface bundling

Cisco IOS XE Fuji 16.7.1

This feature was integrated into Cisco IOS XE Fuji 16.7.1 on the Cisco cBR Series Converged Broadband Routers.