LAG Commands

lag

Syntax

[no] lag lag-id

Context

config

Description

This command enables the context in which Link Aggregation Group (LAG) attributes are defined.

A LAG groups two or more Ethernet links (ports) into one logical link. The aggregation of multiple physical links adds redundancy and improves resiliency between two network devices, and allows for load sharing.

On access, network, and hybrid ports, a LAG supports active/standby and active/active operation.

For active/standby operation, the links must be in different subgroups. Links can be on the same platform or adapter card/module or distributed over multiple components. If an active link in a LAG fails, traffic gets redistributed to the standby link.

Load sharing is supported among the active links in a LAG group.

The no form of this command deletes the LAG from the configuration. A LAG can only be deleted while it is administratively shut down. Any dependencies, such as IP interface configurations, must be removed from the LAG before it can be shut down.

Default

no lag

Parameters

lag-id

the LAG identifier, expressed as a decimal integer

Values

1 to 32

access

Syntax

access

Context

config>lag

Description

This command enables the context to configure access parameters.

Default

n/a

adapt-qos

Syntax

adapt-qos {link | distribute}

Context

config>lag>access

Description

This command specifies how active/active LAG SAP queue scheduler, SAP scheduler (H-QoS), and SAP MSS scheduler QoS rates (as specified by the SLA) are distributed to each of the active LAG ports. This command applies only to access LAGs.

Default

link

Parameters

link

specifies that the full QoS rates are configured on each of the active LAG links for SAP queue schedulers, SAP schedulers (H-QoS), and SAP MSS schedulers

distribute

specifies that the QoS rates are divided equally among the active LAG links for SAP queue schedulers, SAP schedulers (H-QoS), and egress MSS schedulers. For ingress MSS shaper schedulers, the distribute parameter specifies that the QoS rates are divided proportionally among the active link MDAs based on the number of active links on each MDA.

bfd

Syntax

bfd

Context

config>lag

Description

This command creates the bfd context and enables a micro-BFD session over the associated LAG links.

Default

n/a

family

Syntax

family ipv4

Context

config>lag>bfd

Description

This command specifies the address family for the micro-BFD session over the associated LAG links.

Default

ipv4

Parameters

ipv4

specifies that IPv4 encapsulation be used for the micro-BFD session

bfd-on-distributing-only

Syntax

[no] bfd-on-distributing-only

Context

config>lag>bfd>family

Description

This command enables standardized implementation for interworking with other vendors by restricting micro-BFD sessions to links in the LACP distributing state only.

The configuration must be the same for both the local and remote LAG nodes.

The no form of this command disables restricting micro-BFD sessions; this functionality is an enhanced proprietary solution.

Default

no bfd-on-distributing-only

local-ip-address

Syntax

local-ip-address ip-address

no local-ip-address

Context

config>lag>bfd>family

Description

This command is used to specify the IPv4 address of the BFD source.

The no form of this command removes the address from the configuration.

Default

no local-ip-address

Parameters

ip-address

specifies the IPv4 address

Values

a.b.c.d

max-admin-down-time

Syntax

max-admin-down-time [[down-interval] | infinite]

no max-admin-down-time

Context

config>lag>bfd>family

Description

This command specifies the maximum length of time the router continues to forward traffic over a link after the micro-BFD session has transitioned to a down state because it received an Admin Down state message from the far end. The configured time allows the administrator to disable or deprovision the micro-BFD session on the local node before forwarding is halted over the associated links.

The configured interval must be the same for both the local and remote LAG nodes.

The no form of this command removes the time interval from the configuration.

Default

0

Parameters

down-interval

specifies the time, in seconds, that the router continues to forward traffic

Values

0 to 3600

infinite

specifies no end time to forward traffic

max-setup-time

Syntax

max-setup-time [[up-interval] | infinite]

no max-setup-time

Context

config>lag>bfd>family

Description

This command specifies the maximum length of time the router forwards traffic over a link that has transitioned from standby to active before the micro-BFD session is fully established (up state).

The configured interval must be the same for both the local and remote LAG nodes.

The no form of this command returns the timer value to the default (infinite), which indicates that the state of the micro-BFD session is ignored forever.

Note:

If bfd-on-distributing-only is enabled, you cannot configure the max-setup-time to a value between 0 and 3000. Similarly, if max-setup-time is set to a value between 0 and 3000, you cannot enable bfd-on-distributing-only.

Default

infinite

Parameters

up-interval

specifies the time, in milliseconds, that the router forwards traffic

Values

–1 | 0 to 60000

infinite

specifies no end time to forward traffic

multiplier

Syntax

multiplier multiplier

no multiplier

Context

config>lag>bfd>family

Description

This command specifies the detect multiplier used for a micro-BFD session over the associated LAG links. If a BFD control packet is not received within the period specified by the multiplier x receive-interval parameter of the receive-interval command, the session is declared down.

The no form of this command removes the multiplier from the configuration.

Default

3

Parameters

multiplier

specifies the multiplier value

Values

3 to 20

receive-interval

Syntax

receive-interval receive-interval

no receive-interval

Context

config>lag>bfd>family

Description

This command specifies the receive timer used for micro-BFD sessions over the associated LAG links. The receive interval is the expected interval between received BFD control packets.

The no form of this command removes the receive timer from the configuration.

Default

100

Parameters

receive-interval

specifies the interval time, in milliseconds

Values

10 to 100000

remote-ip-address

Syntax

remote-ip-address ip-address

no remote-ip-address

Context

config>lag>bfd>family

Description

This command is used to specify the IPv4 address of the BFD destination.

The no form of this command removes the address from the configuration.

Default

no remote-ip-address

Parameters

ip-address

specifies the IPv4 address

Values

a.b.c.d

shutdown

Syntax

[no] shutdown

Context

config>lag>bfd>family

Description

This command disables micro-BFD sessions for this address family.

The no form of this command re-enables micro-BFD sessions for this address family.

Default

shutdown

transmit-interval

Syntax

transmit-interval transmit-interval

no transmit-interval

Context

config>lag>bfd>family

Description

This command specifies the transmit timer used for micro-BFD sessions over the associated LAG links. The transmit interval is the interval between transmitted BFD control packets.

The no form of this command removes the transmit timer from the configuration.

Default

100

Parameters

transmit-interval

specifies the interval time, in milliseconds

Values

10 to 100000

dynamic-cost

Syntax

[no] dynamic-cost

Context

config>lag

Description

This command enables OSPF or IS-IS costing of a LAG based on the available aggregated, operational bandwidth.

The path cost is dynamically calculated based on the interface bandwidth. OSPF path cost can be changed through the interface metric or the reference bandwidth.

If dynamic cost is configured, costing is applied based on the total number of links configured and the cost advertised is inversely proportional to the number of links available at the time. This requires that the number of links that are up exceeds the configured LAG threshold value; if the number of links that are up falls below the threshold, the configured threshold action determines whether, and at what cost, this LAG will be advertised (see port-threshold).

For example, a physical link in OSPF has a cost associated with it of 100, and the LAG consists of four physical links. The cost associated with the logical link is 25. If one link fails, the cost is automatically adjusted to 33.

If dynamic cost is not configured and OSPF auto-cost is configured, costing is applied based on the total number of links configured. This cost will remain static provided that the number of links that are up exceeds the configured LAG threshold value; if the number of links that are up falls below the threshold, the configured threshold action determines whether, and at what cost, this LAG will be advertised.

If dynamic cost is configured and OSPF auto-cost is not configured, the cost is determined by the cost configured on the OSPF metric, provided that the number of links that are up exceeds the configured LAG threshold value; if the number of links that are up falls below the threshold, the configured threshold action determines whether this LAG will be advertised.

If neither dynamic cost nor OSPF auto-cost is configured, the cost advertised is determined by the cost configured on the OSPF metric, provided that the number of links that are up exceeds the configured LAG threshold value; if the number of links that are up falls below the threshold, the configured threshold action determines whether this LAG will be advertised.

The no form of this command removes dynamic costing from the LAG.

Default

no dynamic-cost

encap-type

Syntax

encap-type {dot1q | null | qinq}

no encap-type

Context

config>lag

Description

This command configures the encapsulation method used to distinguish customer traffic on a LAG.

The encapsulation type of a LAG must match that of its member links. If the encapsulation type of the LAG is changed, the encapsulation type of all its member links also changes.

The encapsulation type can be changed on the LAG only if there is no interface or service associated with it. If the MTU is set to a non-default value, it will be reset to the default value when the encapsulation type is changed.

The no form of this command reverts to the default encapsulation type.

Default

null — all traffic on the link belongs to a single service or VLAN

Parameters

dot1q

ingress Ethernet frames carry IEEE 802.1Q tags, each tag signifying a different service

null

ingress Ethernet frames do not use any tags to indicate a service. As a result, only one service can be configured on a link with null encapsulation.

qinq

ingress frames carry two tags, where the outer tag is the service provider tag and the inner tag is the customer service tag as defined in 802.1ad

hold-time

Syntax

hold-time down hold-down-time

no hold-time

Context

config>lag

Description

This command specifies the delay between detecting that a LAG is down (all active ports are down) and reporting it to the upper layer protocols.

When a failure in a LAG is detected, it is immediately advertised to the rest of the system, but subsequent failures are not advertised to upper layers until the hold-time down interval has expired.

Specifying a hold time is especially useful in a 1:1 active/standby configuration because the time between detecting that the active link in the LAG is down and the time needed to activate the standby link is very short. The hold time prevents the LAG from being operationally down when switching between the active and standby link.

The no form of this command removes any hold time configured.

Default

no hold-time

Parameters

hold-down-time

specifies, in tenths of seconds, the hold time before a failure is reported

Values

0 to 2000

lacp

Syntax

lacp [mode] [administrative-key admin-key] [system-id system-id] [system-priority priority]

no lacp

Context

config>lag

Description

This command specifies the LACP mode of the LAG. By default, the LACP mode is not set.

Per the IEEE 802.1AX-2008 (IEEE 802.3ad) standard, the Link Aggregation Control Protocol (LACP) provides a standardized means for exchanging information between network devices using LAGs. LACP operates in two modes: passive and active. At least one partner must operate in active mode. For example, if the mode on the CE end is passive, the LACP mode on the 7705 SAR end must be active.

The no form of this command disables LACP.

Default

no lacp

Parameters

mode

specifies the mode in which LACP operates

Values

passive — starts transmitting LACP packets only after receiving packets

active — initiates the transmission of LACP packets

admin-key

specifies an administrative key value to identify the aggregation group on each port configured to use LACP. This value should be configured only in exceptional cases. If it is not specified, a random key is assigned.

Values

1 to 65535

Default

32768

system-id

the 6-byte system identifier in hexadecimal format

Values

xx:xx:xx:xx:xx:xx or xx-xx-xx-xx-xx-xx

priority

the system priority

Values

0 to 65535

lacp-xmit-interval

Syntax

lacp-xmit-interval {slow | fast}

no lacp-xmit-interval

Context

config>lag

Description

This command specifies the interval signaled to the peer and tells the peer at which rate it should transmit.

The no form of this command returns the value to the default.

Default

fast

Parameters

slow

transmits packets every 30 seconds

fast

transmits packets every second

lacp-xmit-stdby

Syntax

[no] lacp-xmit-stdby

Context

config>lag

Description

This command enables LACP message transmission on the standby link.

The no form of this command disables LACP message transmission on the standby link. Disable LACP message transmission on the standby link if the peer does not properly follow the IEEE 802.3ax standard regarding the LACP sync bit.

Default

lacp-xmit-stdby

mac

Syntax

mac ieee-address

no mac

Context

config>lag

Description

This command assigns a specific MAC address to the LAG.

The no form of this command returns the MAC address to the default value.

Default

a default MAC address is assigned by the system

Parameters

ieee-address

specifies the 48-bit MAC address in the form aa:bb:cc:dd:ee:ff or aa-bb-cc-dd-ee-ff where aa, bb, cc, dd, ee, and ff are hexadecimal numbers. Allowed values are any non-broadcast, non-multicast MAC, and non-IEEE reserved MAC addresses.

mode

Syntax

mode {access | network | hybrid}

no mode

Context

config>lag

Description

This command configures the LAG for access, network, or hybrid mode operation.

An access port is used for customer-facing traffic on which services are configured. A SAP can only be configured on an access port or channel.

A network port participates in the service provider transport or infrastructure network when network mode is selected.

A hybrid port allows a single port to operate in both access and network modes.

The no form of this command restores the default.

Default

network

Parameters

access

configures the LAG for access mode operation

network

configures the LAG for network mode operation

hybrid

configures the LAG for hybrid mode operation

port

Syntax

port port-id [port-id] [priority priority] [sub-group sub-group-id]

no port port-id

Context

config>lag

Description

This command adds ports (links) to a LAG. Multiple ports can be added in one command as long as the maximum is not exceeded. The number of links in a LAG depends on the platform or adapter card/module and the Ethernet port type.

The port configuration of the first port added to the LAG is used to compare to subsequently added ports. All ports must share the same characteristics (MTU, speed, duplex, and so on) as those of the first port; otherwise, they will not be added to the LAG.

The priority parameter sets the priority of the port, which is used by LACP. The port with the highest priority is the primary port. If two or more ports share the same priority value, the port with the lowest port ID becomes the primary port.

Any configuration changes made to the primary port apply to all member ports of a LAG. For example, port hold-time and MTU settings can be modified directly on the primary port and will be applied to all member ports. Any configuration changes made to non-primary ports are rejected.

Note:

All ports in a LAG must have autonegotiation disabled or set to limited mode (recommended setting is limited). Autonegotiation can be disabled or set to limited mode using the autonegotiate command under the config>port>ethernet context.

The no form of this command removes ports from the LAG.

Default

n/a

Parameters

port-id

specifies the physical port ID in the slot/mda/port format

priority

specifies the priority of a port

Values

1 to 65535

sub-group-id

identifies a LAG subgroup. Each port in a LAG must be a member of a subgroup. If no subgroup is specified for an access port, the configuration will fail. If no subgroup is specified for a network port, the port is assigned to subgroup 1.

Subgroups should only be configured on one side of a LAG, not both. If you configure the 7705 SAR with subgroups to handle active/standby operation, the partner system should not be configured with subgroups. Only having one side perform active/standby selection guarantees a consistent selection and fast convergence. Active/standby selection is signaled through LACP from one side of the LAG to the other.

Values

1 to 4

port-threshold

Syntax

port-threshold value [action {dynamic-cost | down}]

no port-threshold

Context

config>lag

Description

This command sets a threshold value and controls the behavior of the LAG if the number of operational links is equal to or below the threshold value.

The no form of this command returns the value to the default.

Default

0 action down

Parameters

value

the number of operational links at or below which the configured action will be invoked for the LAG. When the number of operational links exceeds the port threshold value, any action taken for being below the threshold value will cease.

Values

0 to 7

action dynamic-cost

specifies that dynamic costing will be activated if the number of operational links is equal to or below the configured threshold value. The LAG will remain operationally up with a cost relative to the number of operational links. The link will only be regarded as operationally down when all links in the LAG are down.

action down

specifies that the LAG will be brought operationally down if the number of operational links is equal to or below the configured threshold value. The LAG will only be regarded as up when the number of operational links exceeds the configured threshold value.

selection-criteria

Syntax

selection-criteria [best-port | highest-count | highest-weight] [slave-to-partner] [subgroup-hold-time hold-time]

no selection-criteria

Context

config>lag

Description

This command specifies which criteria is used to select the active subgroup (link) of a LAG. Every time the configuration of a link changes, the selection algorithm is applied.

The no form of this command returns the value to the default.

Default

highest-count

Parameters

best-port

specifies that all standby ports will have their corresponding transmitters disabled. This parameter is used in static LAG configurations.

highest-count

specifies the subgroup with the highest number of eligible member links. An eligible member link of a LAG is a member that can potentially become active.

A subgroup can have a maximum of one eligible member link.

highest-weight

specifies the subgroup with the highest aggregate weight

slave-to-partner

selects, together with the selection criteria, the active subgroup. An eligible member link of a LAG is a member that can potentially become active. This means it is operationally up (not disabled) for use by the remote side. The slave-to-partner parameter can be used to control whether this latter condition is taken into account. The slave-to-partner parameter does not apply to static LAG configurations.

It is recommended that this parameter be set.

hold-time

specifies the delay time, in tenths of a second, before switching to a newly selected active subgroup from the existing active subgroup. The timer delay applies only if the existing subgroup remains operationally up. If a value of 0 or no value is specified, the switchover occurs immediately. If a value of infinite is specified, no switchover will occur as long as the subgroup remains up; this setting can be overridden with the tools>perform>force>lag-id command. LACP must be enabled on the LAG.

Values

0 to 2000 | infinite

standby-signaling

Syntax

standby-signaling [lacp | power-off]

no standby-signaling

Context

config>lag

Description

This command specifies how the state of a member port is signaled to the remote side when the status corresponding to this member port has a standby value.

The no form of this command turns off standby signaling.

Parameters

lacp

specifies that lacp is active

power-off

specifies that the standby port transmitter is disabled