Contents

1   Overview

This document describes how to configure, monitor, and administer the following types of link aggregation: Multilink PPP (MLPPP) and Multilink Frame Relay (MFR) and Ethernet media link groups. The terms MLPPP bundle and MFR bundle refer to link-aggregated PPP- and Frame Relay-encapsulated DS-1 channels or E1 channels or ports, respectively. The term link group refers to link-aggregated Fast Ethernet (FE) or Gigabit Ethernet (GE) ports with IP over Ethernet (IPoE), Point-to-Point Protocol (PPP) over Ethernet (PPPoE), or 802.1Q encapsulation and link-aggregated ports and channels. The term standby link describes a port in the link group bundle that currently is not carrying traffic but stands by ready to carry traffic if any of the active ports fail.

Link aggregation, whether as a link group, MLPPP bundle, or Multilink Frame Relay (MFR) bundle, provides increased bandwidth and availability. When a number of ports (or channels) are bundled in a link group, the failure or replacement of one link in the bundle does not cause the link group to be taken down because the other links take on the traffic of the one that is out of service. Load balancing and load distribution over the ports in the link group result in increased bandwidth.

The Glossary defines the terminology used in this document.

Figure 1 shows a typical application of bridged link groups:

1.1   MLPPP in This Document

The configuration for MLPPP for PPP-encapsulated DS-1 channels, E1 channels, POS ports, and E1 ports is described in the section Configure an MLPPP Bundle. MLPPP is an extension to PPP that allows a router, such as the SmartEdge router, to use more than one physical link for communication.

MLPPP in this form is often used to provide bandwidth increments between DS-1 channels and DS-3 channels or DS-3 ports, in areas where DS-3 channels or ports are unavailable, or the required bandwidth does not justify the cost of a DS-3 channel or port. For example, four DS-1 channels can be linked together using the MLPPP to provide an aggregate connection of 6 Mbps:

1.1.1   Load Balancing

When using more than one physical link to connect two routers, MLPPP provides a mechanism to load balance the connection across all links in the bundle. Both ends of point-to-point links must be capable of supporting MLPPP connections. The two routers configure the data link by swapping Link Control Protocol (LCP) packets during a link establishment phase. If MLPPP is not successfully negotiated, the connection is not established and an error is logged.

The traffic load on a circuit in an MLPPP bundle is distributed packet by packet in a round-robin over the multiple links in the link bundle.

For a complete discussion of load balancing, see Load Balancing.

1.2   MLPPP in Other Documents

MLPPP of the following types are described in Configuring PPP and PPPoE:

• MLPPP using PPP-encapsulated ATM PVCs

  Using this form of MLPPP, you do not create an MLPPP bundle; instead, the SmartEdge router creates it dynamically.

• MLPPP for L2TP subscribers

  Using this form of MLPPP, you do not create an MLPPP bundle; instead, the SmartEdge router creates it dynamically.

• MLPPP using PPPoE

  Using this form of MLPPP, you do not create an MLPPP bundle; instead, the SmartEdge router creates it dynamically.

1.3   MFR

The SmartEdge router supports MFR, which allow Frame Relay-encapsulated DS-1 channels, clear-channel E1 channels, or clear-channel E1 ports to be aggregated. MFR bundles comply with FRF.16.1, Multilink Frame Relay UNI/NNI Implementation Agreement, which defines the connections between data terminal equipment (DTE) and data communications equipment (DCE) endpoints or between DCE endpoints.

The traffic load on a circuit in an MFR bundle is distributed packet by packet in a round-robin over the multiple links in the link bundle.

The configuration for MFR is described in the section, Configure an MFR Bundle.

1.4   IEEE 802.3ad Link Groups for FE and GE Ports

The SmartEdge router supports the aggregation of FE or GE ports into a single, larger logical pipe, as specified in Part 3 of the IEEE 802.3ad 2000 specification, Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications. The SmartEdge router supports 802.3ad Link Groups with IPoE, PPPoE, and 802.1Q encapsulation.

Three types of non-MLPPP link groups for FE and GE ports are supported by the SmartEdge router. An overview of each follow:

• Ethernet link group: An IEEE 802.3ad network-facing link group that bundles IPoE encapsulated circuits.

  Ports in an Ethernet link group must be network-facing and IPoE encapsulated and have identical configurations, but need not be configured on the same traffic card. You cannot mix FE ports with GE ports in the same link group. You cannot mix ports on different the types of GE traffic cards.

  The ports of an Ethernet link group can be bridged. Details and restrictions are in Section 2. A typical application of bridged link groups is shown in Figure 1.

  The outgoing traffic load in an 802.1Q or Ethernet link group is distributed stream by stream; that is using the source and destination MAC addresses of each traffic stream, a hash algorithm assigns streams to circuits in the link group bundle. Incoming traffic can arrive on any active link. For details, see Load Balancing.

• 802.1Q link group: An IEEE 802.3ad network-facing link group that bundles 802.1Q encapsulated circuits; in other words, 802.1Q PVCs.

  Ports in an 802.1Q link group must be network-facing and be 802.1Q encapsulated and have identical configurations, but need not be configured on the same traffic card. You cannot mix FE ports with GE ports in the same link group. You cannot mix ports on different the types of GE traffic cards.

  The ports and circuits of an 802.1Q link group can be bridged. Details and restrictions are in Section 2.

  The outgoing traffic load in an 802.1Q or Ethernet link group is distributed stream by stream; that is using the source and destination MAC addresses of each traffic stream, a hash algorithm assigns streams to circuits in the link group bundle. Incoming traffic can arrive on any active link. For details, see Load Balancing.

• Access link group: A link group that bundles either PPPoE or 802.1Q single- or double-encapsulated (Q-in-Q) circuits. Access link groups support untagged traffic, single-tagged VLAN traffic, and double-tagged VLAN traffic. Access link group are used in subscriber-facing applications such as QOS. Specified in Part 3 of the IEEE 802.3ad 2000 specification, Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications.

  The ports and circuits of an access link group can be bridged. Details and restrictions are in Section 2.

  The outgoing traffic in an access link group is distributed among the active ports but is not load balanced; that is, the various links in the link bundle, as determined by session and circuit parameters, are assigned subgroup IDs sub-protection group IDs (SPG-IDs) and distributed for each ID (not by source and destination address as in load balancing) so that all traffic in the same subgroup goes through the same port. Incoming traffic can arrive on any active link.

  When more than one port is active in an access link group, the system selects one of the active ports as an egress port for the circuit’s traffic. By default, the system attempts to distribute circuits evenly across all active ports using a round-robin algorithm. For example, if there are two active ports in the link group, half of the circuits will use the one active port for egress traffic and the other half will use the other active port for egress traffic. You can change this behavior by using the protect-group incoming-port command (in access link-group configuration mode). In this case, subscriber egress traffic will egress on the same port on which the subscriber authentication request came in. For example, if a PPPoE subscriber request was received on port 2, the subscriber’s egress traffic will egress on port 2.

  An MDRR policy can be applied to an access link group including 802.1Q VLANs under the link group. For more information, see Modified Deficit Round-Robin Policies.

Note:  

IPv6 packets are supported on network-facing IEEE 802.3ad link groups; that is, IPv6 packets are supported on both the Ethernet and 802.1Q link group types.

1.5   HDLC IEEE 802.3ad Link Groups for POS OC-3 and OC-12 Ports

Link groups can be formed by the aggregation of High-Level Data Link Control (HDLC) encapsulated Packet over SONET/SDH (POS) ports on the following traffic cards:

• OC-3c/STM-1c 8 port card
• OC-12c/STM-4c 4 port card

The following restrictions apply:

• Ports on these cards should be unchannelized POS and configured for the proprietary form of HDLC encapsulation from Cisco.
• A mixture of OC-3 and OC-12 ports cannot be bundled.
• A maximum of eight ports can be bundled in a link group.
• HDLC link groups are not supported on the SmartEdge 100 router.

HDLC link groups support the following protocols:

• IP Version 4 (IPv4)
• Multiprotocol Label Switching (MPLS)
• Label Distribution Protocol (LDP)
• Resource Reservation Protocol (RSVP)
• Open Shortest Path First (OSPF)
• Connectionless Network Protocol (CLNP) for support of IS-IS routing

The following protocols are not supported:

• NAT, Internet control message protocol (ICMP) redirect, and Lawful Intercept
• Unnumbered interfaces
• Bidirectional Forwarding Detection (BFD)

1.6   Load Balancing and Load Distribution

For information on load balancing and load distribution, see Load Balancing.

1.7   Supported Link Aggregation Standards and Recommendations

The SmartEdge router supports the following link aggregation recommendations and standards:

• MLPPP bundles that comply with the following RFCs:
  • PPP encapsulation—RFC 1661, The Point-to-Point Protocol, and RFC 1377, The PPP OSI Network Layer Control Protocol (OSINLCP)
  • MLPPP features—RFC 1990, The PPP Multilink Protocol (MLPPP)
• MFR bundles that comply with FRF.16.1, Multilink Frame Relay UNI/NNI Implementation Agreement.
• Ethernet link groups that comply with the IEEE 802.3ad 2000 specification.
• 802.1Q link groups that comply with the IEEE 802.3ad 2000 specification.
• Access link groups that comply with the specification for 802.3ad-based link aggregation using Link Aggregation Control Protocol (LACP).

1.8   Related Information

Other documents with related tasks and commands include:

• Configuring ATM, Ethernet, and POS Ports
• Configuring Channels and Clear-Channel and Channelized Ports
• Configuring Circuits

2   Configurations and Operations Tasks and Examples

This section provides tasks and examples for configuring and operating link aggregation.

Note:  

Unless otherwise noted, the SmartEdge 100 router supports all commands described in this document.

2.1   Configuring an MLPPP Bundle

To configure an MLPPP bundle, perform the tasks in the following sections.

2.1.1   Configure an MLPPP Bundle

All DS-1 channels, E1 channels, POS ports, or E1 ports in an MLPPP bundle must be configured on the same traffic card, must have identical configurations, and must have PPP encapsulation. Fragmentation and reassembly are not supported in this release; the default maximum received reconstructed unit (MRRU) is set to 1,524 bytes. MRRU is configured by the mp mrru command. Fragmentation must be disabled at the remote peer.

To configure an MLPPP bundle for PPP-encapsulated DS-1 channels, E1 channels, POS ports, or E1 ports, perform the tasks described in Table 1.

Note:  

An MLPPP bundle is always enabled (operational). The shutdown command is not available in link group configuration mode for MLPPP bundles.

2.1.2   Add DS-1 Channels, E1 Channels, POS Ports, or E1 Ports to an MLPPP Bundle

You configure the constituent DS-1 channels, E1 channels, POS ports, or E1 ports for an MLPPP bundle as described in Configuring Channels and Clear-Channel and Channelized Ports but with these restrictions:

• All DS-1 channels must be configured on the same channelized DS-3 or channelized OC-12 to DS-1 traffic card; all E1 channels or ports must be configured on the same channelized STM-1 or E1 traffic card.
• The configuration of each DS-1 channel, E1 channel, or E1 port to be added to the MLPPP bundle must be identical; the only exception is the description of the channel or port.
• Each channel or port must be configured with PPP encapsulation.
• MLPPP on E1 links is supported both for unframed and the fractional E1.
• You do not attach a QoS policy to the channel or port.
• You do not bind any DS-1 channel, E1 channel, POS port, or E1 port that you are adding to an MLPPP bundle; instead you bind the MLPPP bundle to its interface.
• You must enable each DS-1 channel, E1 channel, POS port, or E1 port with the no shutdown command in DS-1 or E1 configuration mode.

To configure and add a DS-1 channel, E1 channel, POS port, or E1 port to an MLPPP bundle, perform the task described in Table 2. For DS-1 channels, E1 channels, or E1 ports, enter this command in DS-1 or E1 configuration mode. For POS ports, enter this command in POS port configuration mode.

Note:  

See the link-group command for the maximum number of ports or channels that can be included in a link group bundle.

2.1.3   MLPPP Bundle Example

This section provides a sample configuration of an MLPPP bundle.

The following example shows how to create an interface, multi, in the local context, assigns an IP address to it, creates an MLPPP bundle, lg-multi, specifies the IP address of the interface as the endpoint discriminator and binds the bundle to the interface; then, the example shows how to configure two DS-1 channels with PPP encapsulation and includes them in the bundle

Create the MLPPP bundle interface and assign an IP address to it:

[local]Redback(config)#context local
[local]Redback(config-ctx)#interface multi
[local]Redback(config-if)#ip address 172.16.1.1/30
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#exit

Create an MLPPP bundle and bind it to an interface:

[local]Redback(config)#link-group lg-multi mp
[local]Redback(config-link-group)#mp endpoint-discriminator ip
[local]Redback(config-link-group)#bind interface multi local
[local]Redback(config-link-group)#exit

Configure a DS-1 channel on DS-3 port 1 and add it to the bundle:

[local]Redback(config)#port channelized-ds3 1/1
[local]Redback(config-ds3)#no shutdown
[local]Redback(config-ds3)#exit
[local]Redback(config)#port ds1 1/1:1
[local]Redback(config-ds1)#encapsulation ppp
[local]Redback(config-ds1)#no shutdown
[local]Redback(config-ds1)#link-group lg-multi
[local]Redback(config-ds1)#exit

Configure a DS-1 channel on DS-3 port 2 and add it to the bundle:

[local]Redback(config)#port channelized-ds3 1/2
[local]Redback(config-ds3)#no shutdown
[local]Redback(config-ds3)#exit
[local]Redback(config)#port ds1 1/2:1
[local]Redback(config-ds1)#encapsulation ppp
[local]Redback(config-ds1)#no shutdown
[local]Redback(config-ds1)#link-group lg-multi
[local]Redback(config-ds1)#exit

2.2   Configuring an MFR Bundle

2.2.1   Configure an MFR Bundle

All DS-1 channels, E1 channels, or E1 ports in an MFR bundle must be configured on the same traffic card, must have identical configurations, and have Frame Relay encapsulation. MFR bundles can include DS-1 channels, E1 channels, or E1 ports. Fragmentation and reassembly as described in FRF.12, Frame Relay Fragmentation Agreement, are not supported in this release. Fragmentation must be disabled at the remote peer.

The number of MFR bundles that you can configure with DS-1 channels or E1 channels or ports on a card and the Frame Relay PVCs in those bundles is restricted in this release. The maximum number of MFR bundles and Frame Relay PVCs must be less than 164 per card according to the following formula:

3 x MFR bundles + MFR PVCs £ 164

For Frame Relay to operate, you must configure the Local Management Interface (LMI) type and the Frame Relay LMI.

Note:  

The LMI is for the MFR bundle.

To configure an MFR bundle, perform the tasks described in Table 3.

2.2.2   Configure an Aggregated Frame Relay PVC

You create an aggregated Frame Relay PVC to represent the PVCs with the same Data Link Connection Identifier (DLCI) on the DS-1 channels, E1 channels, or E1 ports that you intend to add to the MFR bundle. To configure an aggregated Frame Relay PVC, perform the tasks described in Table 4.

2.2.3   Add DS-1 Channels, E1 Channels, or E1 Ports to the MFR Bundle

You configure a constituent DS-1 channel, E1 channel, or E1 port with its Frame Relay encapsulation as described in Configuring Channels and Clear-Channel and Channelized Ports, but with these restrictions:

• All DS-1 channels must be configured on the same channelized OC-12 to DS-1 traffic card; all E1 channels must be configured on the same channelized STM-1 traffic card.
• All DS-1 channels must be configured on the same channelized DS-3 traffic card; all E1 ports must be configured on the same channelized E1 traffic card.
• The configuration of each DS-1channel, E1 channel, or E1 port to be added to the MFR bundle must be identical; the only exception is the description of the channel or port.
• Each channel or port must be configured with Frame Relay encapsulation.
• All E1 channels or ports must be clear-channel channels or ports (using unframed mode).
• You do not attach a QoS policy to the channel or port.
• You do not bind any DS-1 channel, E1 channel, or E1 port that you are adding to an MFR bundle.
• You must enable each DS-1 channel, E1 channel, or E1 port with the no shutdown command in DS-1 or E1 configuration mode.

To configure and add a constituent DS-1 channel, E1 channel, or E1 port to an MFR bundle, perform the additional tasks described in Table 5.

Note:  

Adding a DS-1 channel, E1 channel, or E1 port to the MFR bundle creates a PVC on that channel or port for each aggregated Frame Relay PVC that you have created.

Note:  

If you remove a constituent DS-1 channel, E1 channel, or E1 port from an MFR bundle, either directly with the no link-group command (in DS-1 or E1 configuration mode), or indirectly by deleting the link group with the no link-group command (in global configuration mode), you cannot use the channel as an single-link channel; you can only add it to another link group. To use the channel as a single-link channel, you must first remove it from the configuration, by using the no port ds1 command (in DS-1 configuration mode) or the no port e1 command (in E1 configuration mode), and then reconfigure it.

2.2.4   MFR Bundle Example

This section provides an MFR bundle configuration sample.

The following example shows how to create an MFR bundle, lg-mfr, with a data terminal equipment (DTE) interface and an ITU Local Management Interface (LMI) type and disables it until ready to begin operations. It creates the interfaces, frpvc30 and frpvc40, in the local context for the aggregated Frame Relay PVCs and assigns an IP address to each one. Then it creates two aggregated Frame Relay PVCs and binds them to the frpvc30 and frpvc40 interfaces. Finally, the DS-1 channels are configured and added to the MFR bundle

Create the MFR bundle and configure the Frame Relay LMI:

[local]Redback(config)#link-group lg-mfr mfr
[local]Redback(config-link-group)#frame-relay intf-type dte
[local]Redback(config-link-group)#frame-relay lmi-type itu
[local]Redback(config-link-group)#frame-relay keepalive 6 
[local]Redback(config-link-group)#frame-relay lmi-n391dte 10
[local]Redback(config-link-group)#frame-relay lmi-n392dte 4
[local]Redback(config-link-group)#no shutdown
[local]Redback(config-link-group)#exit

Create the Frame Relay PVC interfaces; assign an IP address to each one:

[local]Redback(config)#context local
[local]Redback(config-ctx)#interface frpvc30
[local]Redback(config-if)#ip address 172.16.3.1/24
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#interface frpvc40
[local]Redback(config-if)#ip address 172.16.4.1/24
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#exit

Create Frame Relay PVC 30 and bind it to its interface:

[local]Redback(config)#link-group lg-mfr mfr
[local]Redback(config-link-group)#frame-relay pvc 30 
[local]Redback(config-link-pvc)#bind interface frpvc30 local
[local]Redback(config-link-pvc)#exit

Create Frame Relay PVC 40 and bind it to its interface:

[local]Redback(config-link-group)#frame-relay pvc 40
[local]Redback(config-link-pvc)#bind interface frpvc40 local
[local]Redback(config-link-pvc)#exit
[local]Redback(config-link-group)#exit
[local]Redback(config-config)#

Configure a DS-1 channel on DS-3 port 3 and add it to the bundle:

[local]Redback(config)#port channelized-ds3 1/3
[local]Redback(config-ds3)#no shutdown
[local]Redback(config-ds3)#exit
[local]Redback(config)#port ds1 1/3:1
[local]Redback(config-ds1)#encapsulation frame-relay
[local]Redback(config-ds1)#no shutdown
[local]Redback(config-ds1)#link-group lg-mfr
[local]Redback(config-ds1)#frame-relay multilink ack-timer 12
[local]Redback(config-ds1)#frame-relay multilink hello-interval 6
[local]Redback(config-ds1)#frame-relay multilink retries 3
[local]Redback(config-ds1)#exit

Configure a DS-1 channel on DS-3 port 4 and add it to the bundle:

[local]Redback(config)#port channelized-ds3 1/4
[local]Redback(config-ds3)#no shutdown
[local]Redback(config-ds3)#exit
[local]Redback(config)#port ds1 1/4:1
[local]Redback(config-ds1)#encapsulation frame-relay
[local]Redback(config-ds1)#no shutdown
[local]Redback(config-ds1)#link-group lg-mfr
[local]Redback(config-ds1)#frame-relay multilink ack-timer 12
[local]Redback(config-ds1)#frame-relay multilink hello-interval 6
[local]Redback(config-ds1)#frame-relay multilink retries 3
[local]Redback(config-ds1)#exit

2.3   Configuring an Ethernet Link Group

This section includes the following topics:

• Configure an Ethernet Link Group
• Add an FE or a GE Port to an Ethernet Link Group
• Ethernet Link Group Example

2.3.1   Configure an Ethernet Link Group

Ports in an Ethernet link group must be network-facing and IPoE-encapsulated, and have identical configurations, but need not be configured on the same traffic card. You cannot mix FE ports with GE ports in the same link group. You cannot mix ports on different the types of GE traffic cards.

To configure an Ethernet link group, perform the tasks described in Table 6. Enter all commands in link group configuration mode, unless otherwise noted.

(1)  The rate circuit and qos commands are not supported for Ethernet link groups.

(2)  Supported only if the bridge is a trunk type. Not supported if the bridge is a tributary type.

Note:  

An Ethernet link group is always enabled (operational). The shutdown command is not available in link group configuration mode for Ethernet link groups.

2.3.2   Add an FE or a GE Port to an Ethernet Link Group

You configure the constituent FE or GE ports for a link group as described in Configuring ATM, Ethernet, and POS Ports but with these restrictions:

• The configuration of each port to be added to the link group must be identical; the only exception is the description of the port.
• You cannot attach a quality of service (QoS) metering, policing, or scheduling policy to an Ethernet or 802.1Q link group.
• All ports must have IPoE encapsulation; this encapsulation is the default.
• All ports must run at the same speed.
• You do not bind any port that you are adding to a link group; instead, you bind the link group to its interface.
• You must enable each port with the no shutdown command (in port configuration mode).

To add a constituent port to an Ethernet link group, perform the task in Table 7. Enter this command in port configuration mode.

Each Ethernet link group is limited to eight ports. You cannot mix FE ports with GE ports in the same access link group or GE3, GE1020, or 10GE ports with any other type of GE ports. You can mix ports on FE traffic cards if the ports on the FE traffic cards are configured to run at 100 Mbps.

2.3.3   Ethernet Link Group Example

The following example shows how to create an interface, etherx, in the local context, assign an IP address to each one, create an Ethernet link group, lg-ether and bind it to the interface, etherx. Then the FE or GE ports are configured and added to the link group

Create the link group interface and assign an IP address to it:

[local]Redback(config)#context local
[local]Redback(config-ctx)#interface etherx
[local]Redback(config-if)#ip address 172.16.0.1/24
[local]Redback(config-if)#exit

Create the link group and bind it to its interface:

[local]Redback(config)#link-group lg-ether ether
[local]Redback(config-link-group)#bind interface etherx local

Configure an FE port and add it to the link group:

[local]Redback(config-config)#port ethernet 5/4
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#link-group lg-ether
[local]Redback(config-port)#exit

Configure another FE port and add it to the link group:

[local]Redback(config-config)#port ethernet 5/5
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#link-group lg-ether
[local]Redback(config-port)#exit

2.4   Configuring an 802.1Q Link Group

This section describes how to configure network-facing ports with 802.1Q encapsulation.

2.4.1   Configure an 802.1Q Link Group for 802.1Q-Encapsulated FE or GE Ports

Ports in an 802.1Q link group must be network-facing and 802.1Q encapsulated and have identical configurations, but need not be configured on the same traffic card. You cannot mix FE ports with GE ports in the same link group. You cannot mix ports on different the types of GE traffic cards.

To configure an 802.1Q link group for 802.1Q-encapsulated FE or GE ports, perform the tasks described in Table 8. Enter all commands in link group configuration mode, unless otherwise noted.

(1)  The rate circuit and qos commands are not supported for 802.1Q link groups.

Note:  

An 802.1Q link group is always enabled (operational). The shutdown command is not available in link group configuration mode for 802.1Q link groups.

2.4.2   Configure an Aggregated 802.1Q PVC in the 802.1Q Link Group

Ports in an 802.1Q link group must be 802.1Q encapsulated and have identical configurations, but need not be configured on the same traffic card. You cannot mix FE ports with GE ports in the same link group. You cannot mix ports on different the types of GE traffic cards.

For FE or GE ports configured with 802.1Q encapsulation, the 802.1Q PVCs and the untagged traffic on each port are referred to as the constituent PVCs. If the constituent PVCs are aggregated in a link group as separate logical pipes, they are referred to as aggregated PVCs.

You create an aggregated 802.1Q PVC to represent the PVCs with the same tag value on the FE or GE ports that you intend to add to the 802.1Q link group.

To configure an aggregated 802.1Q PVC in the 802.1Q link group, perform the tasks described in Table 9; enter all commands in link PVC configuration mode, unless otherwise noted.

(1)  The rate circuit and qos commands are not supported for 802.1Q link groups.

(2)  The SmartEdge router does not support binding an aggregated 802.1Q PVC in an 802.1Q link group to a bridged interface.

2.4.3   Add an FE or a GE Port to the 802.1Q Link Group

You configure the FE or GE ports for a link group as described in Configuring ATM, Ethernet, and POS Ports but with these restrictions:

• The configuration of each port to be added to the link group must be identical; the only exception is the description of the port.
• All ports must have 802.1Q encapsulation; IPoE encapsulation is the default.
• All ports must be at the same speed.
• You cannot attach a quality of service (QoS) metering, policing, or scheduling policy to an Ethernet or 802.1Q link group.
• You do not bind any port that you are adding to a link group; instead, you bind the link group and the aggregated PVCs to their interfaces.
• You must enable each port with the no shutdown command (in port configuration mode).

To add a constituent port to an 802.1Q link group, perform the task described in Table 10. Enter this command in port configuration mode.

Each 802.1Q link group is limited to eight ports. You cannot mix FE ports with GE ports in the same access link group or GE3, GE1020, or 10GE ports with any other type of GE ports. You can mix ports on FE traffic cards if the ports on the FE traffic cards are configured to run at 100 Mbps.

Note:  

Adding an FE or a GE port to the link group creates an 802.1Q PVC on that port for each aggregated 802.1Q PVC that you created.

2.4.4   802.1Q Link Group Aggregated PVCs Example

The following example shows how to create the interfaces, vlans, vlan10, and vlan20, in the local context, assigns an IP address to each one, creates an 802.1Q link group, lg-vlans and binds it to the vlans interface. Then, the example shows how to configure two 802.1Q PVCs and binds them to the vlan10 and vlan20 interfaces. Finally, the FE or GE ports are configured and added to the link group

Create the link group interface and assign an IP address to it:

[local]Redback(config)#context local
[local]Redback(config-ctx)#interface vlans
[local]Redback(config-if)#ip address 172.16.0.1/24
[local]Redback(config-if)#exit

Create the link group and bind it to its interface:

[local]Redback(config)#link-group lg-vlans dot1q
[local]Redback(config-link-group)#bind interface vlans local

Create the PVC interfaces and assign an IP address to each one:

[local]Redback(config)#context local
[local]Redback(config-ctx)#interface vlan10
[local]Redback(config-if)#ip address 172.16.1.1/24
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#interface vlan20
[local]Redback(config-if)#ip address 172.16.2.1/24
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#exit

Create PVC 10 and bind it to its interface:

[local]Redback(config)#link-group lg-vlans dot1q 
[local]Redback(config-link-group)#dot1q pvc 10 
[local]Redback(config-link-pvc)#bind interface vlan10 local
[local]Redback(config-link-pvc)#exit

Create PVC 20 and bind it to its interface:

[local]Redback(config-link-group)#dot1q pvc 20
[local]Redback(config-link-pvc)#bind interface vlan20 local
[local]Redback(config-link-pvc)#exit
[local]Redback(config-link-group)#exit

Configure another FE port and add it to the link group:

[local]Redback(config-config)#port ethernet 5/2
[local]Redback(config-port)#encapsulation dot1q
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#link-group lg-vlans
[local]Redback(config-port)#exit

Configure another FE port and add it to the link group:

[local]Redback(config-config)#port ethernet 5/3
[local]Redback(config-port)#encapsulation dot1q
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#link-group lg-vlans
[local]Redback(config-port)#exit

2.5   Configuring an Access Link Group

This section describes how to configure subscriber-facing ports with PPPoE or 802.1Q encapsulation.

2.5.1   Configuration Guidelines for Access Link Groups

Consider the following guidelines when configuring access link groups:

• Ports in an access link group must have PPPoE or 802.1Q encapsulation and identical configurations, but need not be configured on the same traffic card. The encapsulation of the port and encapsulation of the link group must match. The system displays an error message if they do not match.
• All member ports in an access link-group bundle must belong to the same type of traffic card - PPA2 or PPA3. Additionally, all member ports must have same port speed.
• You can create individual 802.1Q PVCs, ranges of static 802.1Q PVCs, or ranges of on-demand 802.1Q PVCs as aggregated PVCs within an access link group. You can also create and aggregate these PVCs within an 802.1Q tunnel, a range of static 802.1Q tunnels, or a range of on-demand 802.1Q tunnels.
• In addition to tunnel encapsulation, encapsulation types include 802.1Q, PPPoE, and multiprotocol. Raw encapsulation is not supported.
• You configure any 802.1Q tunnel or PVC in link PVC configuration mode as you would in dot1q PVC configuration mode, including the assignment of an 802.1Q profile For information about configuring 802.1Q tunnels and PVCs, see Configuring Circuits.
• The encapsulation of the link group determines which of the various bind commands are available to bind the link group to its interface. For access link groups with PPPoE encapsulation, the choices are bind authentication or bind subscriber (in link group configuration mode). The maximum number the sessions must be greater than one if you specify the bind authentication command. For access link groups with 802.1Q encapsulation, the only choice is bind interface.
• You can configure both static and dynamic clientless IP service selection (CLIPS) circuits on Ethernet ports and aggregated 802.1Q PVCs within an access link group. CLIPS over access link groups with internal DHCP server is also supported.
• Table 11 lists the types of cross-connections that you can configure with 802.1Q PVCs and tunnels within an access link group.

• You can specify quality of service (QoS) parameters, such as maximum and minimum rates, priority, and hierarchical mode; and QoS policies, such as metering, policing, and scheduling.
• The encapsulation of the 802.1Q PVC, whether it is a tunnel or a PVC and whether it is a range of PVCs, determines which of the various bind commands are available to bind the PVC or its range to its interface.
• For FE or GE ports configured with 802.1Q encapsulation, the 802.1Q PVCs and the untagged traffic on each port are referred to as the constituent PVCs. If the constituent PVCs are aggregated in a link group as separate logical pipes, they are referred to as aggregated PVCs.
• You can create an aggregated 802.1Q PVC or 802.1Q tunnel to represent the PVCs with the same tag value on the FE or GE ports that you intend to add to an access link group with 802.1Q encapsulation.

2.5.2   Configure an Access Link Group for FE or GE Ports

Note:  

An access link group is always enabled (operational). The shutdown command is not available in link group configuration mode for access link groups.

2.5.3   Configure the Optional Parameters of an Access Link Group for FE or GE Ports

2.5.4   Configure an Access Link Group for Aggregated 802.1Q PVCs or 802.1Q Tunnels

2.5.5   Configure the Optional Parameters of an Aggregated 802.1Q PVC (VLAN) of an Access Link Group

2.5.6   Add an FE or a GE Port to the Access Link Group

If the FE or GE ports are configured with 802.1Q encapsulation, the 802.1Q PVCs and the untagged traffic on each port, referred to as the constituent PVCs, are aggregated in separate logical pipes, referred to as aggregated PVCs.

You configure the FE or GE ports for an access link group as described in Configuring ATM, Ethernet, and POS Ports but with these restrictions:

• The configuration of each port to be added to the link group must be identical; the only exception is the description of the port.
• All ports must be at the same speed.
• You do not bind any port that you are adding to the access link group; instead, you bind the link group to its interface and the aggregated PVCs to their interfaces.
• You must enable each port with the no shutdown command (in port configuration mode).

To add a constituent FE or GE port to an access link group, perform the task described in Table 16. Enter this command in port configuration mode.

You cannot mix FE ports with GE ports in the same access link group or GE3, GE1020, or 10GE ports with any other type of GE ports. You can mix ports on FE traffic cards if the ports on the FE traffic cards are configured to run at 100 Mbps.

Note:  

Adding an FE or a GE port to the link group creates an 802.1Q PVC on that port for each aggregated 802.1Q PVC that you created.

2.5.7   Configuring an Economical Access Link Group

To configuration economical hierarchical nodes in access link groups follow the steps in Table 17. This table does not describe other features of access link groups, but this information can be found in other tables in this section.

2.5.8   Example of Access Link Group with Aggregated On-Demand PVCs

The following example shows how to create an access link group that aggregates two GE ports on a ge3–4–port traffic card. On-demand PVCs are created for the link group as they are needed to support link redundancy:

[local]Redback#config
Enter configuration commands, one per line, 'end' to exit
[local]Redback(config)#link-group test1 access
[local]Redback(config-link-group)#encapsulation dot1q
[local]Redback(config-link-group)#dot1q pvc on-demand 10 through 19
[local]Redback(config-dot1q-pvc)#end
[local]Redback#config
Enter configuration commands, one per line, 'end' to exit
[local]Redback(config)#port ethernet 5/2
[local]Redback(config-port)#encapsulation dot1q
[local]Redback(config-port)#link-group test1
[local]Redback(config-port)#end
[local]Redback#config
Enter configuration commands, one per line, 'end' to exit
[local]Redback(config)#port ethernet 5/3
[local]Redback(config-port)#encapsulation dot1q
[local]Redback(config-port)#link-group test1
[local]Redback(config-port)#end

After configuring the test1 link group, use the show link-group... detail command to display the details of its configuration. Notice that the link group ID is 26. The SmartEdge router automatically sets the link group ID value as shown in the following:

[local]Redback#show link-group test1 detail
Link-Group: test1, ID   : 26, State : Down
------------------------------------------------------------------------------
Ccct count      : 2                              Grouping        : LoadShare
Card Type       : ether-12-port                  Type            : access

Bindings        : Unbound                        Minimum-links   : 1

Maximum-links   : 1                              Prot-Group-Type : round-robin
Internal Handle : 255/22:1:27/1/1/20
Description     :
Constituent Circuits:
 1. 5/2               (Down)|  0.00%
 2. 5/3               (Down)|  0.00%

2.5.9   Example of Aggregated 802.1Q Tunnel in a Cross Connected Access Link Group

The following example shows the creation of an aggregated 802.1Q tunnel configured in a cross connected access link group. An IP ACL filter is applied to the 802.1Q PVC in the tunnel:

[local]Redback(config)#link-group LGXC7 access
[local]Redback(config-link-group)#encapsulation dot1q
[local]Redback(config-link-group)#qos hierarchical mode strict
[local]Redback(config-link-group)#dot1q pvc 200 encapsulation 1qtunnel
[local]Redback(config-dot1q-pvc)#exit
[local]Redback(config-link-group)#dot1q pvc 200:1
[local]Redback(config-dot1q-pvc)#ip access-group ACL_1 context CTX_1 in count
[local]Redback(config-dot1q-pvc)#bind bypass
!
[local]Redback(config)#link-group LGXC8 access
[local]Redback(config-link-group)#encapsulation dot1q
[local]Redback(config-link-group)#qos hierarchical mode strict
[local]Redback(config-link-group)#dot1q pvc 200 encapsulation 1qtunnel
[local]Redback(config-dot1q-pvc)#exit
[local]Redback(config-link-group)#dot1q pvc 100:1
[local]Redback(config-dot1q-pvc)#bind bypass
!
[local]Redback(config)#port ethernet 11/2
local]Redback(config-port)#encapsulation dot1q
local]Redback(config-port)#link-group LGXC7
! Cannot add NON-TM card based port to an access link-group when qos hierarchical mode 
! strict is set
!
[local]Redback(config)#port ethernet 11/3
local]Redback(config-port)#encapsulation dot1q
local]Redback(config-port)#link-group LGXC8
! Cannot add NON-TM card based port to an access link-group when qos hierarchical mode 
! strict is set
!
[local]Redback(config)#xc-group xcg4
[local]Redback(config-xc-group)xc lg LGXC8 vlan-id 100:1 to lg LGXC7 vlan-id 200:1

2.5.10   Example of Economical Access Link Group

The following example shows the configuration of an economical access link group. In an economical access link group, replicas of the circuit features of active ports are not maintained on the standby ports; therefore, when an active port fails and its standby port becomes active, a small number of packets are lost in the transition. The economic behavior reduces the SmartEdge router resources used by the access link group, allowing more of these resources to become available to other applications. The replicate keyword applies to economical access link groups and specifies whether the circuit features of active ports are replicated on the other active ports as shown in the following:

[local]Redback(config)#link-group abc access economical
[local]Redback(config-link-group)#qos hierarchical mode strict
[local]Redback(config-link-group)#maximum-links 8
[local]Redback(config-link-group)#encapsulation dot1q
[local]Redback(config-link-group)#dot1q pvc 100 encapsulation 1qtunnel replicate
[local]Redback(config-dot1q-pvc)#qos policy queuing pwfq1
[local]Redback(config-dot1q-pvc)#dot1q pvc 100:1 encapsulation pppoe
[local]Redback(config-dot1q-pvc)#qos policy metering mymeter1 inherit
[local]Redback(config-dot1q-pvc)#qos rate maximum 300
[local]Redback(config-dot1q-pvc)#bind auth chap max 10

2.6   Configuring an HDLC Link Group for OC-3 and OC-12 Ports

This section contains the following:

• Configuration Steps
• HDLC Link Group Example

2.6.1   Configuration Steps

To configure a link group for HDLC-encapsulated OC-3 or OC-12 ports, perform the tasks described in Table 18. Enter all commands in link group configuration mode, unless otherwise noted.

2.6.2   HDLC Link Group Example

The following configuration shows how to bundle three POS ports to the lg1 link group and apply the QoS policing policy slow1 to each port. The link group lg1 is bound to the interface pos1 to which an access-list filter, named filter1, acts on inbound packets:

[local]Redback(config)#context local
[local]Redback(config-ctx)#ip access-list filter1

The following portion of this example shows the configuration of access-list:

!...
[local]Redback(config-ctx)#interface pos1
[local]Redback(config-if)#ip address 10.1.1.1/24
[local]Redback(config-if)#ip access-group filter1 in
[local]Redback(config-if)#end
!...
[local]Redback(config)#link-group lg1 hdlc
[local]Redback(config-link-group)#bind interface pos1 local
[local]Redback(config-link-group)#end
!...

Ports should be unchannelized POS and use HDLC encapsulation (defaults). OC-3 ports and OC-12 ports cannot be bundled together. A maximum of eight ports is allowed per link group:

[local]Redback(config)#port pos 11/2
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#qos policy policing slow1
[local]Redback(config-port)#link-group lg1
[local]Redback(config-link-group)#end
!...
[local]Redback(config)#port pos 12/1
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#qos policy policing slow1
[local]Redback(config-port)#link-group lg1
[local]Redback(config-link-group)#end
!...
[local]Redback(config)#port pos 12/2
[local]Redback(config-port)#no shutdown
[local]Redback(config-port)#qos policy policing slow1
[local]Redback(config-port)#link-group lg1
[local]Redback(config-link-group)#end

2.7   Link Group Operations

To monitor and troubleshoot link groups, perform the appropriate task listed in Table 19. Enter the debug commands in exec mode; enter the show commands in any mode.

2.8   Bridged Link Groups Examples

In the following scenario, four link groups are created. Two network link groups, lg1 and lg3, are bound to the ac1 and ac3 interfaces, respectively. Two access link groups, lg2 and lg4, are bound to the ac2 and ac4 interfaces, respectively. The ac1 and ac2 interfaces are part of the SE1 bridge, while the ac3 and ac4 interfaces are part of the SE2 bridge.

Configure a network-facing bridge profile, bp1:

[local]Redback#config
Enter configuration commands, one per line, 'end' to exit
[local]Redback(config)#service multiple-service
[local]Redback(config)#bridge profile bp1
[local]Redback(config-bridge-profile)#trunk
[local]Redback(config-bridge-profile)#exit

Configure a subscriber-facing bridge profile, bp2:

[local]Redback(config)#bridge profile bp2
[local]Redback(config-bridge-profile)#mac-limit 10
[local]Redback(config-bridge-profile)#broadcast rate-limit 10 burst 333
[local]Redback(config-bridge-profile)#exit

Configure two bridge groups in the local context, bridgeSE1 and bridgeSE2:

[local]Redback(config)#context local
[local]Redback(config-ctx)#bridge bridgeSE1
[local]Redback(config-ctx)#exit
[local]Redback(config-ctx)#bridge bridgeSE2
[local]Redback(config-ctx)#exit

In the local context, configure four bridged interfaces named ac1, ac2, ac3, and ac4. Attach two interfaces to each bridge; specifically, attach ac1 and ac2 to bridgeSE1 bridge and attach ac3 and ac4 to bridgeSE2 bridge:

[local]Redback(config-ctx)#interface ac1 bridge
[local]Redback(config-if)#bridge name bridgeSE1
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#interface ac2 bridge
[local]Redback(config-if)#bridge name bridgeSE1
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#interface ac3 bridge
[local]Redback(config-if)#bridge name bridgeSE2
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#interface ac4 bridge
[local]Redback(config-if)#bridge name bridgeSE2
[local]Redback(config-if)#exit
[local]Redback(config-ctx)#exit

Configure lg1 as an Ethernet link group. Because Ethernet link groups must be network-facing, lg1 is provisioned by bp1 (a network-facing bridge profile), and bound to ac1 (an interface to the bridgeSE1 bridge group:

[local]Redback(config)#link-group lg1 ether
[local]Redback(config-link-group)#bind interface ac1 local
[local]Redback(config-link-group)#bridge profile bp1
[local]Redback(config-bridge-profile)#exit

Configure lg2 as an access link group. Because access link groups must be subscriber facing, lg2 is provisioned by bp2 (a subscriber-facing bridge profile) and bound to ac2 (an interface to the bridgeSE1 bridge group). The bridgeSE1 bridge group has two interfaces, one that is network facing and the other that is subscriber facing:

[local]Redback(config)#link-group lg2 access
[local]Redback(config-link-group)#bind interface ac2 local
[local]Redback(config-link-group)#bridge profile bp2
[local]Redback(config-bridge-profile)#exit

Configure lg3 as an 802.1Q link group. Because 802.1Q link groups must be network-facing, lg3 is provisioned by bp1 (a network-facing bridge profile), and bound to ac3 (an interface to the bridgeSE2 bridge group:

[local]Redback(config)#link-group lg3 dot1q
[local]Redback(config-link-group)#dot1q pvc 1
[local]Redback(config-link-pvc)#bind interface ac3 local
[local]Redback(config-link-pvc)#bridge profile bp1
[local]Redback(config-bridge-profile)#exit

Configure lg4 as an access link group. Because access link groups must be subscriber facing, lg4 is provisioned by bp2 (a subscriber-facing bridge profile) and bound to ac4 (an interface to the bridgeSE2 bridge group). The bridgeSE2 bridge group has two interfaces, one that is network- facing and the other that is subscriber facing:

[local]Redback(config)#link-group lg4 access
[local]Redback(config-link-group)#encap dot1q
[local]Redback(config-link-group)#dot1q pvc 1
[local]Redback(config-dot1q-pvc)#bind interface ac4 local
[local]Redback(config-dot1q-pvc)#bridge profile bp2
[local]Redback(config-dot1q-pvc)#exit
[local]Redback(config-link-group)#exit

The following lines show the resulting configuration:

[local]Redback#show config link-group
Building configuration...

Current configuration:
!
link-group lg2 access
 bind interface ac2 local
!
link-group lg4 access
 encapsulation dot1q
 dot1q pvc 1
  bind interface ac4 local
!
link-group lg1 ether
 bind interface ac1 local
!
link-group lg3 dot1q
 dot1q pvc 1
   bind interface ac3 local
!
!
end
[local]Redback#show config interface
Building configuration...

Current configuration:
context local
!
 interface ac1 bridge
  bridge name bridgeSE1
!
 interface ac2 bridge
  bridge name bridgeSE1
!
 interface ac3 bridge
  bridge name bridgeSE2
!
 interface ac4 bridge
  bridge name bridgeSE2
!
 interface mgmt
  ip address 10.18.17.102/24
!

2.9   Multichassis Link Aggregation Example

This section provides an example of multichassis link aggregation, where two system share a common endpoint in a SmartEdge router. LACP manages the connections in an access link group bundle so that only one link to one satellite chassis is active at any time:

The following example shows how to configure the preceding illustrated system. The first set of commands create and configure the access link group named LAG-1, which bundles the two links to the two external chassis:

[local]Redback(config)#system lacp priority 1
[local]Redback(config)#link-group LAG-1 access
[local]Redback(config-link-group)#bind interface LAG-1 local
[local]Redback(config-link-group)#mac-address auto
[local]Redback(config-link-group)#lacp active
[local]Redback(config-link-group)#lacp ignore-system-id
[local]Redback(config-link-group)#maximum-links 1

The second set of commands adds the SmartEdge router port that interfaces to Switch A into the link group bundle:

[local]Redback(config)#port ethernet 2/6
[local]Redback(config-port)#link-group LAG-1
[local]Redback(config-link-group)#lacp priority 20

The third set of commands adds the SmartEdge router port that interfaces to Switch B into the link group bundle:

[local]Redback(config)#port ethernet 3/6
[local]Redback(config-port)#link-group LAG-1
[local]Redback(config-link-group)#lacp priority 20

The following configuration guidelines apply to configuration of the multichassis access link groups:

• Set the SmartEdge router priority to 0, 1, or any other value that is higher in priority than the satellite LACP systems so that the system is elected the LACP master.

  system lacp priority command (global configuration mode)

  The satellite LACP systems should have system priorities set to 2 or higher (lower priority than the SmartEdge router). The default value is 2.

• Configure the link aggregation group by using the link-group command as one of the following types:
  • link-group... access
  • link-group... ether
  • link-group... dot1q

  Multichassis link aggregation is supported only in access, Ethernet, and dot1q link groups.

• Set the maximum number of active links in the link group to 1.

  maximum-links command (link group configuration mode)

• Configure the link group to ignore the system ID.

  lacp ignore-system-id command (link group configuration mode)

Glossary