Configuring Link Bundling

The Link Bundling feature allows you to group multiple point-to-point links together into one logical link and provide higher bidirectional bandwidth, redundancy, and load balancing between two routers. A virtual interface is assigned to the bundled link. The component links can be dynamically added and deleted from the virtual interface.

The virtual interface is treated as a single interface on which one can configure an IP address and other software features used by the link bundle. Packets sent to the link bundle are forwarded to one of the links in the bundle.

A link bundle is simply a group of ports that are bundled together and act as a single link. The advantages of link bundles are as follows:

  • Multiple links can span several line cards to form a single interface. Thus, the failure of a single link does not cause a loss of connectivity.

  • Bundled interfaces increase bandwidth availability, because traffic is forwarded over all available members of the bundle. Therefore, traffic can flow on the available links if one of the links within a bundle fails. Bandwidth can be added without interrupting packet flow.

Cisco IOS XR software supports the following method of forming bundles of Ethernet interfaces:

  • IEEE 802.3ad—Standard technology that employs a Link Aggregation Control Protocol (LACP) to ensure that all the member links in a bundle are compatible. Links that are incompatible or have failed are automatically removed from a bundle.

Limitations and Compatible Characteristics of Ethernet Link Bundles

This list describes the properties and limitations of ethernet link bundles:

  • The router supports mixed speed bundles. Mixed speed bundles allow member links of different bandwidth to be configured as active members in a single bundle. The ratio of the bandwidth for bundle members must not exceed 10. Also, the total weight of the bundle must not exceed 64. For example, 100Gbps link and 10Gbps links can be active members in a bundle and load-balancing on member links is based on bandwidth weightage.

  • The weight of each bundle member is the ratio of its bandwidth to the lowest bandwidth member. Total weight of the bundle is the sum of weights or relative bandwidth of each bundle member. Since the weight for a bundle member is greater than or equal to 1 and less than or equal to 10, the total member of links in a bundle is less than 64 in mixed bundle case.

  • Any type of Ethernet interfaces can be bundled, with or without the use of LACP (Link Aggregation Control Protocol).

  • A single router can support a maximum of 256 bundle interfaces. Link bundles of only physical interfaces are supported.

  • When enabling HQoS profile, the maximum available trunks by default (bundle main + sub-interfaces) are 256. If you need more trunks, configure the hw-module profile bundle-scale <256/512/1024> command. With HQoS enabled on bundle interfaces, the maximum priority level supported is 4.

  • The following limitations apply to the number of supported bundle members with HQoS profile on Layer2 and Layer3 intefaces:

    • Maximum of 1024 trunks (128 physical interfaces + 896 sub-interfaces) and 16 bundle members.

    • Maximum of 256 trunks (128 physical interfaces + 128 sub-interfaces) and 64 bundle members.

    • Maximum of 512 trunks (128 physical interfaces + 384 sub-interfaces) and 32 bundle members.

  • The following limitations apply to bundle sub-interfaces and the number of members per bundle :

    • Maximum of 1024 bundle sub-interfaces, each containing up to 16 member-links.

    • Maximum of 256 bundle sub-interfaces, each containing up to 64 member-links

    • Maximum of 512 bundle sub-interfaces, each containing up to 32 member-links

  • Physical layer and link layer configuration are performed on individual member links of a bundle.

  • Configuration of network layer protocols and higher layer applications is performed on the bundle itself.

  • IPv4 and IPv6 addressing is supported on ethernet link bundles.

  • A bundle can be administratively enabled or disabled.

  • Each individual link within a bundle can be administratively enabled or disabled.

  • Ethernet link bundles are created in the same way as Ethernet channels, where the user enters the same configuration on both end systems.

  • QoS is supported and is applied proportionally on each bundle member.

  • In case static MAC address is configured on a bundle-ether interface, the following limitations are applied:

    • Locally generated packets, such as ICMP, BGP, and so on, going out from the interface have the source MAC address as the statically configured MAC address.

    • Transit (forwarded) packets going out of the interface do not have the configured static MAC as source MAC address. In such a scenario, the upper 36-bits come from the system MAC address (or the original/dynamic MAC address) and the lower 12-bits come from the MAC address configured on the bundle. To check the dynamic pool of MAC addresses included, use the show ethernet mac-allocation detail command.

      For example, if the dynamic MAC address was 008A.9624.48D8 and the configured static MAC address is 0011.2222.ABCD. Then, the source MAC for transit (forwarded) traffic will be 008A.9624.4BCD.


      Note

      This limitation can cause traffic blackholing for the transit traffic, in case there is L2 ACL applied for security purpose. In such case, it is necessary to add permit statement for both MAC addresses in the L2 ACL.

  • Load balancing (the distribution of data between member links) is done by flow instead of by packet. Data is distributed to a link in proportion to the bandwidth of the link in relation to its bundle.

  • All links within a single bundle must terminate on the same two systems.

  • Bundled interfaces are point-to-point.

  • A link must be in the up state before it can be in distributing state in a bundle.

  • Only physical links can be bundle members.

  • Multicast traffic is load balanced over the members of a bundle. For a given flow, the internal processes selects the member link, and the traffic for the flow is sent over that member.

Configuring Ethernet Link Bundles

This section describes how to configure an Ethernet link bundle.


Note

In order for an Ethernet bundle to be active, you must perform the same configuration on both connection endpoints of the bundle.


Tip

You can programmatically perform the configuration using openconfig-if-aggregate.yang OpenConfig data model. To get started with using data models, see the Programmability Configuration Guide for Cisco NCS 5500 Series Routers.

SUMMARY STEPS

  1. configure
  2. interface Bundle-Ether bundle-id
  3. ipv4 address ipv4-address mask
  4. bundle minimum-active bandwidth kbps
  5. bundle minimum-active links links
  6. bundle maximum-active links links [hot-standby]
  7. exit
  8. interface HundredGigE interface-path-id
  9. bundle id bundle-id [mode {active | on | passive}]
  10. bundle port-priority priority
  11. no shutdown
  12. exit
  13. bundle id bundle-id [mode {active | passive | on}] no shutdown exit
  14. end or commit
  15. exit
  16. exit
  17. Perform Step 1 through Step 15 on the remote end of the connection.
  18. show bundle Bundle-Ether bundle-id
  19. show lacp Bundle-Ether bundle-id

DETAILED STEPS

Step 1

configure

Example:


RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step 2

interface Bundle-Ether bundle-id

Example:


RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 3

Creates a new Ethernet link bundle with the specified bundle-id. The range is 1 to 65535.

This interface Bundle-Ether command enters you into the interface configuration submode, where you can enter interface specific configuration commands are entered. Use the exit command to exit from the interface configuration submode back to the normal global configuration mode.

Step 3

ipv4 address ipv4-address mask

Example:


RP/0/RP0/CPU0:router(config-if)# ipv4 address 10.1.2.3 255.0.0.0

Assigns an IP address and subnet mask to the virtual interface using the ipv4 address configuration subcommand.

Note

 

  • Only a Layer 3 bundle interface requires an IP address.

Step 4

bundle minimum-active bandwidth kbps

Example:


RP/0/RP0/CPU0:router(config-if)# bundle minimum-active bandwidth 580000

(Optional) Sets the minimum amount of bandwidth required before a user can bring up a bundle.

Step 5

bundle minimum-active links links

Example:


RP/0/RP0/CPU0:router(config-if)# bundle minimum-active links 2

(Optional) Sets the number of active links required before you can bring up a specific bundle.

Step 6

bundle maximum-active links links [hot-standby]

Example:


RP/0/RP0/CPU0:router(config-if)# bundle maximum-active links 1 hot-standby

(Optional) Implements 1:1 link protection for the bundle, which causes the highest-priority link in the bundle to become active and the second-highest-priority link to become the standby. Also, specifies that a switchover between active and standby LACP-enabled links is implemented per a proprietary optimization.

Note

 

  • The priority of the active and standby links is based on the value of the bundle port-priority command.

Step 7

exit

Example:


RP/0/RP0/CPU0:router(config-if)# exit

Exits interface configuration submode for the Ethernet link bundle.

Step 8

interface HundredGigE interface-path-id

Example:


RP/0/RP0/CPU0:router(config)# interface HundredGigE 0/1/0/1

Enters interface configuration mode for the specified interface.

Enter the HundredGigE keyword to specify the interface type. Replace the interface-path-id argument with the node-id in the rack /slot /module format.

Step 9

bundle id bundle-id [mode {active | on | passive}]

Example:


RP/0/RP0/CPU0:router(config-if)# bundle id 3 mode on

Adds the link to the specified bundle.

To enable active or passive LACP on the bundle, include the optional mode active or mode passive keywords in the command string.

To add the link to the bundle without LACP support, include the optional mode on keywords with the command string.

Note

 

  • If you do not specify the mode keyword, the default mode is on (LACP is not run over the port).

Step 10

bundle port-priority priority

Example:


RP/0/RP0/CPU0:router(config-if)# bundle port-priority 1

(Optional) If you set the bundle maximum-active links command to 1, you must also set the priority of the active link to the highest priority (lowest value) and the standby link to the second-highest priority (next lowest value). For example, you can set the priority of the active link to 1 and the standby link to 2.

Step 11

no shutdown

Example:


RP/0/RP0/CPU0:router(config-if)# no shutdown

(Optional) If a link is in the down state, bring it up. The no shutdown command returns the link to an up or down state depending on the configuration and state of the link.

Step 12

exit

Example:


RP/0/RP0/CPU0:router(config-if)# exit

Exits interface configuration submode for the Ethernet interface.

Step 13

bundle id bundle-id [mode {active | passive | on}] no shutdown exit

Example:


RP/0/RP0/CPU0:router(config)# interface TenGigE 0/1/0/1


RP/0/RP0/CPU0:router(config-if)# bundle id 3

RP/0/RP0/CPU0:router(config-if)# bundle port-priority 2

RP/0/RP0/CPU0:router(config-if)# no shutdown

RP/0/RP0/CPU0:router(config-if)# exit

RP/0/RP0/CPU0:router(config)# interface TenGigE 0/1/0/1

RP/0/RP0/CPU0:router(config-if)# bundle id 3

RP/0/RP0/CPU0:router(config-if)# no shutdown

RP/0/RP0/CPU0:router(config-if)# exit

(Optional) Repeat Step 8 through Step 11 to add more links to the bundle.

Step 14

end or commit

Example:


RP/0/RP0/CPU0:router(config-if)# end

or 


RP/0/RP0/CPU0:router(config-if)# commit

Saves configuration changes.

  • When you issue the end command, the system prompts you to commit changes: 

    
Uncommitted changes found, commit them before exiting(yes/no/cancel)?
[cancel]:

  • Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.

  • Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.

  • Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.

  • Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.

Step 15

exit

Example:


RP/0/RP0/CPU0:router(config-if)# exit

Exits interface configuration mode.

Step 16

exit

Example:


RP/0/RP0/CPU0:router(config)# exit

Exits global configuration mode.

Step 17

Perform Step 1 through Step 15 on the remote end of the connection.

Brings up the other end of the link bundle.

Step 18

show bundle Bundle-Ether bundle-id

Example:

RP/0/RP0/CPU0:router# show bundle Bundle-Ether 3

(Optional) Shows information about the specified Ethernet link bundle.

Step 19

show lacp Bundle-Ether bundle-id

Example:


RP/0/RP0/CPU0:router# show lacp Bundle-Ether 3

(Optional) Shows detailed information about LACP ports and their peers.

Configuring LACP Fallback

This section describes how to configure the LACP Fallback feature.

SUMMARY STEPS

  1. configure
  2. interface Bundle-Ether bundle-id
  3. bundle lacp-fallback timeout timeout value
  4. end or commit
  5. show bundle infrastructure database ma bdl-info Bundle-e1010 | inc text
  6. show bundle infrastructure database ma bdl-info Bundle-e1015 | inc text

DETAILED STEPS

Step 1

configure

Example:


RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step 2

interface Bundle-Ether bundle-id

Example:


RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 3

Creates and names a new Ethernet link bundle.

The interface Bundle-Ether command enters into the interface configuration submode, where you can enter interface-specific configuration commands. Use the exit command to exit from the interface configuration submode back to the normal return to global configuration mode.

Step 3

bundle lacp-fallback timeout timeout value

Example:


RP/0/RP0/CPU0:router(config-if)# bundle lacp-fallback timeout 4

Enables the LACP Fallback feature.

Step 4

end or commit

Example:


RP/0/RP0/CPU0:router(config-subif)# commit

Saves configuration changes.

Step 5

show bundle infrastructure database ma bdl-info Bundle-e1010 | inc text

Example:

RP/0/RP0/CPU0:router# show bundle infrastructure database ma bdl-info Bundle-e1010 | inc "fallback"

(Optional) Shows the MA information of the bundle manager.

Step 6

show bundle infrastructure database ma bdl-info Bundle-e1015 | inc text

Example:

RP/0/RP0/CPU0:router# show bundle infrastructure database ma bdl-info Bundle-e1015 | inc "fallback"

(Optional) Shows the MA information of the bundle manager.

VLANs on an Ethernet Link Bundle

802.1Q VLAN subinterfaces can be configured on 802.3ad Ethernet link bundles. Keep the following information in mind when adding VLANs on an Ethernet link bundle:

  • There is no separate limit defined for Layer 3 sub-interfaces on a bundle. However, an overall system limit of 4000 is applicable for NCS5001 and NCS5002, while a limit of 2000 is applicable for NCS5011.


Note

The memory requirement for bundle VLANs is slightly higher than standard physical interfaces.

To create a VLAN subinterface on a bundle, include the VLAN subinterface instance with the interface Bundle-Ether command, as follows:

interface Bundle-Ether interface-bundle-id.subinterface

After you create a VLAN on an Ethernet link bundle, all VLAN subinterface configuration is supported on that link bundle.

VLAN subinterfaces can support multiple Layer 2 frame types and services, such as Ethernet Flow Points - EFPs) and Layer 3 services.

Layer 2 EFPs are configured as follows: 


interface bundle-ether instance.subinterface l2transport. encapsulation dot1q xxxxx

Layer 3 VLAN subinterfaces are configured as follows: 


interface bundle-ether instance.subinterface, encapsulation dot1q xxxxx

Note

The difference between the Layer 2 and Layer 3 interfaces is the l2transport keyword. Both types of interfaces use dot1q encapsulation .

Configuring VLAN over Bundles

This section describes how to configure a VLAN bundle. The creation of a VLAN bundle involves three main tasks:

SUMMARY STEPS

  1. Create an Ethernet bundle.
  2. Create VLAN subinterfaces and assign them to the Ethernet bundle.
  3. Assign Ethernet links to the Ethernet bundle.

DETAILED STEPS

Step 1

Create an Ethernet bundle.

Step 2

Create VLAN subinterfaces and assign them to the Ethernet bundle.

Step 3

Assign Ethernet links to the Ethernet bundle.

These tasks are describe in detail in the procedure that follows.


Note

In order for a VLAN bundle to be active, you must perform the same configuration on both ends of the bundle connection.

SUMMARY STEPS

  1. configure
  2. interface Bundle-Ether bundle-id
  3. ipv4 address ipv4-address mask
  4. bundle minimum-active bandwidth kbps
  5. bundle minimum-active links links
  6. bundle maximum-active links links [hot-standby]
  7. exit
  8. interface Bundle-Ether bundle-id.vlan-id
  9. encapsulation dot1qvlan-id
  10. ipv4 address ipv4-address mask
  11. no shutdown
  12. exit
  13. Repeat Step 9 through Step 12 to add more VLANS to the bundle you created in Step 2.
  14. end or commit
  15. exit
  16. exit
  17. configure
  18. interface {TenGigE | FortyGigE | HundredGigE}interface-path-id

DETAILED STEPS

Step 1

configure

Example:


RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step 2

interface Bundle-Ether bundle-id

Example:


RP/0/RP0/CPU0:router#(config)# interface Bundle-Ether 3

Creates and names a new Ethernet link bundle.

This interface Bundle-Ether command enters you into the interface configuration submode, where you can enter interface-specific configuration commands. Use the exit command to exit from the interface configuration submode back to the normal global configuration mode.

Step 3

ipv4 address ipv4-address mask

Example:


RP/0/RP0/CPU0:router(config-if)# ipv4 address 10.1.2.3 255.0.0.0

Assigns an IP address and subnet mask to the virtual interface using the ipv4 address configuration subcommand.

Step 4

bundle minimum-active bandwidth kbps

Example:


RP/0/RP0/CPU0:router(config-if)# bundle minimum-active bandwidth 580000

(Optional) Sets the minimum amount of bandwidth required before a user can bring up a bundle.

Step 5

bundle minimum-active links links

Example:


RP/0/RP0/CPU0:router(config-if)# bundle minimum-active links 2

(Optional) Sets the number of active links required before you can bring up a specific bundle.

Step 6

bundle maximum-active links links [hot-standby]

Example:


RP/0/RP0/CPU0:router(config-if)# bundle maximum-active links 1 hot-standby

(Optional) Implements 1:1 link protection for the bundle, which causes the highest-priority link in the bundle to become active and the second-highest-priority link to become the standby. Also, specifies that a switchover between active and standby LACP-enabled links is implemented per a proprietary optimization.

Note

 

The priority of the active and standby links is based on the value of the bundle port-priority command.

Step 7

exit

Example:


RP/0/RP0/CPU0:router(config-if)# exit

Exits the interface configuration submode.

Step 8

interface Bundle-Ether bundle-id.vlan-id

Example:


RP/0/RP0/CPU0:router#(config)# interface Bundle-Ether 3.1

Creates a new VLAN, and assigns the VLAN to the Ethernet bundle you created in Step 2.

Replace the bundle-id argument with the bundle-id you created in Step 2.

Replace the vlan-id with a subinterface identifier.

Range is from 1 to 4093 inclusive (0, 4094, and 4095 are reserved).

Note

 

When you include the .vlan-id argument with the interface Bundle-Ether bundle-id command, you enter subinterface configuration mode.

Step 9

encapsulation dot1qvlan-id

Example:


RP/0/RP0/CPU0:router(config-subif)# encapsulation dot1q 100

Sets the Layer 2 encapsulation of an interface.

Step 10

ipv4 address ipv4-address mask

Example:


RP/0/RP0/CPU0:router#(config-subif)# ipv4 address 10.1.2.3/24

Assigns an IP address and subnet mask to the subinterface.

Step 11

no shutdown

Example:


RP/0/RP0/CPU0:router#(config-subif)# no shutdown

(Optional) If a link is in the down state, bring it up. The no shutdown command returns the link to an up or down state depending on the configuration and state of the link.

Step 12

exit

Example:


RP/0/RP0/CPU0:router(config-subif)# exit

Exits subinterface configuration mode for the VLAN subinterface.

Step 13

Repeat Step 9 through Step 12 to add more VLANS to the bundle you created in Step 2.

(Optional) Adds more subinterfaces to the bundle.

Step 14

end or commit

Example:


RP/0/RP0/CPU0:router(config-subif)# end

or 


RP/0/RP0/CPU0:router(config-subif)# commit

Saves configuration changes.

  • When you issue the end command, the system prompts you to commit changes: 

    
Uncommitted changes found, commit them before
exiting(yes/no/cancel)?
[cancel]:

    - Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.

    - Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.

    - Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.

  • Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.

Step 15

exit

Example:


RP/0/RP0/CPU0:router(config-subif)# end

Exits interface configuration mode.

Step 16

exit

Example:


RP/0/RP0/CPU0:router(config)# exit

Exits global configuration mode.

Step 17

configure

Example:


RP/0/RP0/CPU0:router # configure

Enters global configuration mode.

Step 18

interface {TenGigE | FortyGigE | HundredGigE}interface-path-id

Example:


RP/0/RP0/CPU0:router(config)# interface TenGigE 1/0/0/0

Enters interface configuration mode for the Ethernet interface you want to add to the Bundle.

Enter the GigabitEthernet or TenGigE keyword to specify the interface type. Replace the interface-path-id argument with the node-id in the rack/slot/module format.

Note

 

A VLAN bundle is not active until you add an Ethernet interface on both ends of the link bundle.

LACP Short Period Time Intervals

As packets are exchanged across member links of a bundled interface, some member links may slow down or time-out and fail. LACP packets are exchanged periodically across these links to verify the stability and reliability of the links over which they pass. The configuration of short period time intervals, in which LACP packets are sent, enables faster detection and recovery from link failures.

Short period time intervals are configured as follows:

  • In milliseconds

  • In increments of 100 milliseconds

  • In the range 100 to 1000 milliseconds

  • The default is 1000 milliseconds (1 second)

  • Up to 64 member links

  • Up to 1280 packets per second (pps)

After 6missed packets, the link is detached from the bundle.

When the short period time interval is not configured, LACP packets are transmitted over a member link every 30 seconds by default.

When the short period time interval is configured, LACP packets are transmitted over a member link once every 1000 milliseconds (1 second) by default. Optionally, both the transmit and receive intervals can be configured to less than 1000 milliseconds, independently or together, in increments of 100 milliseconds (100, 200, 300, and so on).

When you configure a custom LACP short period transmit interval at one end of a link, you must configure the same time period for the receive interval at the other end of the link.


Note

You must always configure the transmit interval at both ends of the connection before you configure the receive interval at either end of the connection. Failure to configure the transmit interval at both ends first results in route flapping (a route going up and down continuously). When you remove a custom LACP short period, you must do it in reverse order. You must remove the receive intervals first and then the transmit intervals.

Configuring the Default LACP Short Period Time Interval

This section describes how to configure the default short period time interval for sending and receiving LACP packets on a Gigabit Ethernet interface. This procedure also enables the LACP short period.

SUMMARY STEPS

  1. configure
  2. interface HundredGigEinterface-path
  3. bundle id number mode active
  4. lacp period short
  5. end or commit

DETAILED STEPS

Step 1

configure

Example:


RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step 2

interface HundredGigEinterface-path

Example:


RP/0/RP0/CPU0:router(config)# interface HundredGigE 0/1/0/1

Creates a Gigabit Ethernet interface and enters interface configuration mode.

Step 3

bundle id number mode active

Example:


RP/0/RP0/CPU0:router(config-if)# bundle id 1 mode active

Specifies the bundle interface and puts the member interface in active mode.

Step 4

lacp period short

Example:


RP/0/RP0/CPU0:router(config-if)# lacp period short

Configures a short period time interval for the sending and receiving of LACP packets, using the default time period of 1000 milliseconds or 1 second.

Step 5

end or commit

Example:


RP/0/RP0/CPU0:router(config-if)# end

or 


RP/0/RP0/CPU0:router(config-if)# commit

Saves configuration changes.

  • When you issue the end command, the system prompts you to commit changes: 

    
Uncommitted changes found, commit them before
exiting(yes/no/cancel)?
[cancel]:

    - Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.

    - Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.

    - Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.

  • Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.

Example

This example shows how to configure the LACP short period time interval to the default time of 1000 milliseconds (1 second): 


config
interface HundredGigE 0/1/0/1
   bundle id 1 mode active
   lacp period short 
   commit

The following example shows how to configure custom LACP short period transmit and receive intervals to less than the default of 1000 milliseconds (1 second): 


config
interface HundredGigE 0/1/0/1
   bundle id 1 mode active
   lacp period short 
   commit


config
interface HundredGigE 0/1/0/1
    lacp period short transmit 100
   commit


config
interface HundredGigE 0/1/0/1
   lacp period short receive 100
   commit

Configuring Custom LACP Short Period Time Intervals

This section describes how to configure custom short period time intervals (less than 1000 milliseconds) for sending and receiving LACP packets on a Gigabit Ethernet interface.


Note

You must always configure the transmit interval at both ends of the connection before you configure the receive interval at either end of the connection. Failure to configure the transmit interval at both ends first results in route flapping (a route going up and down continuously). When you remove a custom LACP short period, you must do it in reverse order. You must remove the receive intervals first and then the transmit intervals.

SUMMARY STEPS

  1. configure
  2. interface Bundle-Ether bundle-id
  3. ipv4 address ipv4-address mask
  4. bundle minimum-active bandwidth kbps
  5. bundle minimum-active links links
  6. bundle maximum-active links links
  7. exit
  8. interface Bundle-Ether bundle-id.vlan-id
  9. dot1q vlan vlan-id
  10. ipv4 address ipv4-address mask
  11. no shutdown
  12. exit
  13. Repeat Step 7 through Step 12 to add more VLANs to the bundle you created in Step 2.
  14. end or commit
  15. exit
  16. exit
  17. show ethernet trunk bundle-ether instance
  18. configure
  19. interface {HundredGigE } interface-path-id
  20. bundle id bundle-id [mode {active | on | passive}]
  21. no shutdown
  22. Repeat Step 19 through Step 21 to add more Ethernet interfaces to the VLAN bundle.
  23. end or commit
  24. Perform Step 1 through Step 23 on the remote end of the VLAN bundle connection.
  25. show bundle Bundle-Ether bundle-id [reasons]
  26. show ethernet trunk bundle-ether instance

DETAILED STEPS

Step 1

configure

Example:


RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step 2

interface Bundle-Ether bundle-id

Example:


RP/0/RP0/CPU0:router(config)# interface Bundle-Ether 3

Creates and names a new Ethernet link bundle.

This interface Bundle-Ether command enters you into the interface configuration submode, where you can enter interface-specific configuration commands. Use the exit command to exit from the interface configuration submode back to the normal global configuration mode.

Step 3

ipv4 address ipv4-address mask

Example:


RP/0/RP0/CPU0:router(config-if)# ipv4 address 10.1.2.3 255.0.0.0

Assigns an IP address and subnet mask to the virtual interface using the ipv4 address configuration subcommand.

Step 4

bundle minimum-active bandwidth kbps

Example:


RP/0/RP0/CPU0:router(config-if)# bundle minimum-active bandwidth 580000

(Optional) Sets the minimum amount of bandwidth required before a user can bring up a bundle.

Step 5

bundle minimum-active links links

Example:


RP/0/RP0/CPU0:router(config-if)# bundle minimum-active links 2

(Optional) Sets the number of active links required before you can bring up a specific bundle.

Step 6

bundle maximum-active links links

Example:


RP/0/RP0/CPU0:router(config-if)# bundle maximum-active links 1

(Optional) Designates one active link and one link in standby mode that can take over immediately for a bundle if the active link fails (1:1 protection).

Note

 

  • The default number of active links allowed in a single bundle is 8.

  • If the bundle maximum-active command is issued, then only the highest-priority link within the bundle is active. The priority is based on the value from the bundle port-priority command, where a lower value is a higher priority. Therefore, we recommend that you configure a higher priority on the link that you want to be the active link.

Step 7

exit

Example:


RP/0/RP0/CPU0:router(config-if)# exit

Exits the interface configuration submode.

Step 8

interface Bundle-Ether bundle-id.vlan-id

Example:


RP/0/RP0/CPU0:router#(config)# interface Bundle-Ether 3.1

Creates a new VLAN, and assigns the VLAN to the Ethernet bundle you created in Step 2.

Replace the bundle-id argument with the bundle-id you created in Step 2.

Replace the vlan-id with a subinterface identifier. Range is from 1 to 4093 inclusive (0, 4094, and 4095 are reserved).

Note

 

  • When you include the vlan-id argument with the interface Bundle-Ether bundle-id command, you enter subinterface configuration mode.

Step 9

dot1q vlan vlan-id

Example:


RP/0/RP0/CPU0:router(config-subif)# dot1q vlan 10

Assigns a VLAN to the subinterface.

Replace the vlan-id argument with a subinterface identifier. Range is from 1 to 4093 inclusive (0, 4094, and 4095 are reserved).

Step 10

ipv4 address ipv4-address mask

Example:


RP/0/RP0/CPU0:router(config-subif)# ipv4 address 10.1.2.3/24

Assigns an IP address and subnet mask to the subinterface.

Step 11

no shutdown

Example:


RP/0/RP0/CPU0:router(config-subif)# no shutdown

(Optional) If a link is in the down state, bring it up. The no shutdown command returns the link to an up or down state depending on the configuration and state of the link.

Step 12

exit

Example:


RP/0/RP0/CPU0:router(config-subif)# exit

Exits subinterface configuration mode for the VLAN subinterface.

Step 13

Repeat Step 7 through Step 12 to add more VLANs to the bundle you created in Step 2.

(Optional) Adds more subinterfaces to the bundle.

Step 14

end or commit

Example:


RP/0/RP0/CPU0:router(config-subif)# end

or 


RP/0/RP0/CPU0:router(config-subif)# commit

Saves configuration changes.

  • When you issue the end command, the system prompts you to commit changes: 
Uncommitted changes found, commit them before exiting (yes/no/cancel)?

  • Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.

  • Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.

  • Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.

  • Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.

Step 15

exit

Example:


RP/0/RP0/CPU0:router(config-subif)# exit

Exits interface configuration mode.

Step 16

exit

Example:


RP/0/RP0/CPU0:router(config)# exit

Exits global configuration mode.

Step 17

show ethernet trunk bundle-ether instance

Example:


RP/0/RP0/CPU0:router# show ethernet trunk bundle-ether 5

(Optional) Displays the interface configuration.

The Ethernet bundle instance range is from 1 through 65535.

Step 18

configure

Example:


RP/0/RP0/CPU0:router # configure

Enters global configuration mode.

Step 19

interface {HundredGigE } interface-path-id

Example:


RP/0/RP0/CPU0:router(config)# interface HundredGigE 0/1/0/1

Enters the interface configuration mode for the Ethernet interface you want to add to the Bundle.

Enter the HundredGigE keyword to specify the interface type. Replace the interface-path-id argument with the node-id in the rack/slot/module format.

Note

 

  • A VLAN bundle is not active until you add an Ethernet interface on both ends of the link bundle.

Step 20

bundle id bundle-id [mode {active | on | passive}]

Example:


RP/0/RP0/CPU0:router(config-if)# bundle-id 3

Adds an Ethernet interface to the bundle you configured in Step 2 through Step 13.

To enable active or passive LACP on the bundle, include the optional mode active or mode passive keywords in the command string.

To add the interface to the bundle without LACP support, include the optional mode on keywords with the command string.

Note

 

  • If you do not specify the mode keyword, the default mode is on (LACP is not run over the port).

Step 21

no shutdown

Example:


RP/0/RP0/CPU0:router(config-if)# no shutdown

(Optional) If a link is in the down state, bring it up. The no shutdown command returns the link to an up or down state depending on the configuration and state of the link.

Step 22

Repeat Step 19 through Step 21 to add more Ethernet interfaces to the VLAN bundle.

—

Step 23

end or commit

Example:


RP/0/RP0/CPU0:router(config-subif)# end

or 


RP/0/RP0/CPU0:router(config-subif)# commit

Saves configuration changes.

  • When you issue the end command, the system prompts you to commit changes: 
Uncommitted changes found, commit them before exiting (yes/no/cancel)?

  • Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.

  • Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.

  • Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.

  • Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.

Step 24

Perform Step 1 through Step 23 on the remote end of the VLAN bundle connection.

Brings up the other end of the link bundle.

Step 25

show bundle Bundle-Ether bundle-id [reasons]

Example:

RP/0/RP0/CPU0:router# show bundle Bundle-Ether 3 reasons

(Optional) Shows information about the specified Ethernet link bundle.

The show bundle Bundle-Ether command displays information about the specified bundle. If your bundle has been configured properly and is carrying traffic, the State field in the show bundle Bundle-Ether command output will show the number “4,” which means the specified VLAN bundle port is “distributing.”

Step 26

show ethernet trunk bundle-ether instance

Example:


RP/0/RP0/CPU0:router# show ethernet trunk bundle-ether 5

(Optional) Displays the interface configuration.

The Ethernet bundle instance range is from 1 through 65535.

Bundle Consistency Checker

Table 1. Feature History Table

Feature Name

Release Information

Feature Description

Bundle Consistency Checker (BCC)

Release 7.3.1

From the running configuration, Bundle Consistency Checker (BCC) fetches information about the ingress/egress traffic from the bundle, sub-bundle, and active member nodes and saves it in the database. BCC also collects data from all the running nodes and then compares it with the information saved in the database. Any inconsistencies, programming errors, stale entries are reported.

In a scaled setup, a bundle programming check is difficult to perform and time consuming. Moreover, an issue is reported only when the user detects it, and not automatically. During multiple test executions, it isn’t possible to detect the initial failure, which causes other subsequent failures. Bundle Consistency Checker (BCC) implements bundle programming and consistency check by using the following steps:

  1. BCC uses the running configuration to detect discrepancies.

  2. BCC forms a Bundle Consistency Checker Data Base (BCCDB) with the bundle, sub-bundle, or member information fetched from the running configuration.

  3. BCC dumps the required data from all available nodes. It then uses BCCDB as a source to verify bundle programming and consistency in all other layer dumps.

  4. BCC reports inconsistencies, programming errors, stale entries, and deletes any pending objects.

Supporting Interfaces

The following interfaces support BCC:

  • Bundle

  • Bundle sub-interface

The following table lists BCC behaviour during inconsistencies in bundle configuration or programming errors.

Case

BCC Behaviour

When no bundle is configured

 
Router# show bundle consistency 
Building configuration...
Dumping Data............................ Done
Parsing Data............................ Not Done

BCC Stopped: Found 3 info/exceptions/errors

Logs Preview:

2020-07-13 10:34:22,774: INFO: Bundlemgr PD dont have any bundle data

2020-07-13 10:34:22,832: INFO: BMPI dont have any bundle data

2020-07-13 10:34:23,728: INFO: No Bundle is configured/No member is added to Bundle

Logs: 
/var/log/bcc_exception.log
/var/log/bcc_debug.log

When a bundle is configured but no member is added

 
Router# show bundle consistency
Building configuration...
Dumping Data............................ Done
Parsing Data............................ Not Done

BCC Stopped: Found 4 info/exceptions/errors

Logs Preview:

2020-07-13 10:36:32,513: INFO: Bundlemgr PD dont have any bundle data

2020-07-13 10:36:32,566: INFO: No member is added to bundle BE1(0x3c00400c)

2020-07-13 10:36:32,566: INFO: BMPI dont have any bundle data

2020-07-13 10:36:33,453: INFO: No Bundle is configured/No member is added to Bundle

Logs: 
/var/log/bcc_exception.log
/var/log/bcc_debug.log

When a bundle is configured and members are added

 
Router# show bundle consistency
Building configuration...
Dumping Data............................ Done
Parsing Data............................ Done
Bundle Consistency Check................ Done
Bundle Programming Check................ Done
Stale Entry Check....................... Done
Bundle Health Check..................... Done

Overall Results:

Inconsistencies             : 0        Stale Entries                : 0
BCM Programming Error       : 0        Delete Pending DPA Objects   : 0
Info/Error/Python Exception : 0        Overall Bundle Health Status : WARNING

Execute 'show bundle status' to see detailed reason for 'WARNING' in bundle health check

When there is no encapsulation configuration for L2 or L3 sub-bundle or no member for L2 bundle

 
Router# show bundle consistency
Building configuration...
Dumping Data............................ Done
Parsing Data............................ Done
Bundle Consistency Check................ Done
Bundle Programming Check................ Done
Stale Entry Check....................... Done
Bundle Health Check..................... Done

Overall Results:

Inconsistencies             : 0        Stale Entries                : 0
BCM Programming Error       : 0        Delete Pending DPA Objects   : 0
Info/Error/Python Exception : 3        Overall Bundle Health Status : WARNING

Execute 'show bundle status' to see detailed reason for 'WARNING' in bundle health check

Logs Preview:


2020-07-12 17:38:26,568: INFO: No member is added to bundle BE2(0x80042bc) ==> l2 bundle main

2020-07-12 17:38:32,573: interface Bundle-Ether1.1: Dont have any encapsulation config. ==> l3 sub

2020-07-12 17:38:32,574: interface Bundle-Ether1.130: Dont have any encapsulation config.  ==> l2sub

Logs:

/var/log/bcc_inconsistencies.log
/var/log/bcc_programming_error.log
/var/log/bcc_stale_entries.log
/var/log/bcc_delay_delete.log
/var/log/bcc_bundle_health.log
/var/log/bcc_exception.log
/var/log/bcc_debug.log

During programming errors

 
Router# show bundle consistency

Building configuration...
Dumping Data............................ Done
Parsing Data............................ Done
Bundle Consistency Check................ Done
Bundle Programming Check................ Done
Stale Entry Check....................... Done
Bundle Health Check..................... Done

Overall Results:

Inconsistencies             : 0        Stale Entries                : 0
BCM Programming Error       : 1        Delete Pending DPA Objects   : 0
Info/Error/Python Exception : 0        Overall Bundle Health Status : WARNING

Execute 'show bundle status' to see detailed reason for 'WARNING' in bundle health check

Logs Preview:

2020-07-12 18:48:22,658: Programming Error 1: BE1(0x80041ec) NPU 0,0/RP0/CPU0 Vlan Domain 0x33 != GigabitEthernet0_0_0_2 Vlan Domain 0xa

Logs:

/var/log/bcc_inconsistencies.log
/var/log/bcc_programming_error.log
/var/log/bcc_stale_entries.log
/var/log/bcc_delay_delete.log
/var/log/bcc_bundle_health.log
/var/log/bcc_exception.log
/var/log/bcc_debug.log

Information About Configuring Link Bundling

To configure link bundling, you must understand the following concepts:

IEEE 802.3ad Standard

The IEEE 802.3ad standard typically defines a method of forming Ethernet link bundles.

For each link configured as bundle member, the following information is exchanged between the systems that host each end of the link bundle:

  • A globally unique local system identifier

  • An identifier (operational key) for the bundle of which the link is a member

  • An identifier (port ID) for the link

  • The current aggregation status of the link

This information is used to form the link aggregation group identifier (LAG ID). Links that share a common LAG ID can be aggregated. Individual links have unique LAG IDs.

The system identifier distinguishes one router from another, and its uniqueness is guaranteed through the use of a MAC address from the system. The bundle and link identifiers have significance only to the router assigning them, which must guarantee that no two links have the same identifier, and that no two bundles have the same identifier.

The information from the peer system is combined with the information from the local system to determine the compatibility of the links configured to be members of a bundle.

The MAC address of the first link attached to a bundle becomes the MAC address of the bundle itself. The bundle uses this MAC address until that link (the first link attached to the bundle) is detached from the bundle, or until the user configures a different MAC address. The bundle MAC address is used by all member links when passing bundle traffic. Any unicast or multicast addresses set on the bundle are also set on all the member links.


Note

We recommend that you avoid modifying the MAC address, because changes in the MAC address can affect packet forwarding.

Link Bundle Configuration Overview

The following steps provide a general overview of the link bundle configuration. Keep in mind that a link must be cleared of all previous network layer configuration before it can be added to a bundle:

  1. In global configuration mode, create a link bundle. To create an Ethernet link bundle, enter the interface Bundle-Ether command.

  2. Assign an IP address and subnet mask to the virtual interface using the ipv4 address command.

  3. Add interfaces to the bundle you created in Step 1 with the bundle id command in the interface configuration submode.

    You can add up to 32 links to a single bundle.

  4. You can optionally implement 1:1 link protection for the bundle by setting the bundle maximum-active links command to 1. Performing this configuration causes the highest-priority link in the bundle to become active and the second-highest-priority link to become the standby. (The link priority is based on the value of the bundle port-priority command.) If the active link fails, the standby link immediately becomes the active link.


Note

A link is configured as a member of a bundle from the interface configuration submode for that link.

Link Switchover

By default, a maximum of 64 links in a bundle can actively carry traffic. If one member link in a bundle fails, traffic is redirected to the remaining operational member links.

You can optionally implement 1:1 link protection for a bundle by setting the bundle maximum-active links command to 1. By doing so, you designate one active link and one or more dedicated standby links. If the active link fails, a switchover occurs and a standby link immediately becomes active, thereby ensuring uninterrupted traffic.

If the active and standby links are running LACP, you can choose between an IEEE standard-based switchover (the default) or a faster proprietary optimized switchover. If the active and standby links are not running LACP, the proprietary optimized switchover option is used.

Regardless of the type of switchover you are using, you can disable the wait-while timer, which expedites the state negotiations of the standby link and causes a faster switchover from a failed active link to the standby link.

To do so, you can use the lacp fast-switchover command.

LACP Fallback

The LACP Fallback feature allows an active LACP interface to establish a Link Aggregation Group (LAG) port-channel before the port-channel receives the Link Aggregation and Control Protocol (LACP) protocol data units (PDU) from its peer. With the LACP Fallback feature configured, the router allows the server to bring up the LAG, before receiving any LACP PDUs from the server, and keeps one port active. This allows the server to establish a connection to PXE server over one Ethernet port, download its boot image and then continue the booting process. When the server boot process is complete, the server fully forms an LACP port-channel.