1. Overview
A link aggregation group (LAG) combines multiple physical links into a single logical interface which is referred to as a bundle interface. These physical links are connected between two devices. The device uses LACP protocol to bundle the member links and create high speed connections. Although a bundle can be created based on static configuration, bandwidth can be increased by adding member links to the bundle. This also allows load sharing among the physical links. Thus, a group of ports combined together is called a link aggregation group, or LAG.
The LAG interface combines the bandwidth of the individual member links. The properties like speed and bandwidth of the individual member links should be the same to make it part of that LAG. The traffic which is directed towards the LAG interface is sent on the individual member links. This traffic is not pinned to a specific member link but rather determined by a specific flow. This hash could be calculated based on various fields in the packet.
1.1. Supported Platforms
Not all features are necessarily supported on each hardware platform. Refer to the Platform Guide for the features and the sub-features that are or are not supported by each platform.
1.2. LAG Interface Modes
The LAG interface could be formed statically or dynamically. LACP protocol helps to bring up the interface dynamically. The two modes of LAG interface are:
-
Static LAG: In this mode, the member links do not initiate or process any of the LACP packets received. The device brings up the LAG interface without LACP negotiation.
-
Dynamic LAG: In this mode, the member links process the LACP packets received. Under this mode, there two sub modes:
-
active: LACP packets are generated on each of the member links on the transmit side.
-
passive: LACP packets are generated on the member link in response to the LACP packet received. That means, at least one side of the LAG should be configured as
activeto bring up the LAG interface.
-
1.3. Layer2 and Layer 3 Interfaces
LAG interfaces can be used as layer 2 and layer 3 interfaces. A regular layer 2 or layer 3 interface can be created on top of the single LAG interface. These interfaces can be divided based on 802.1q VLAN ID’s. Multiple layer 3 interfaces can be created and each of them can be associated with different instances.
1.4. LACP (Link Aggregation Control Protocol)
LACP is part of an IEEE specification (802.3ad) that allows several physical ports to be grouped to form a single logical interface. LACP allows a switch to negotiate an LAG by sending LACP packets on its member links. It negotiates the various configuration parameters to bring up the individual member links.
1.5. Supported Number of LAG Interfaces on Platforms
The following tables provide maximum number of LAG interfaces and members per LAG supported on each hardware platform.
1.5.1. Access-Leaf Platforms
| Platform | Max. Number of LAG Interfaces Supported | Number of LAG Members Supported |
|---|---|---|
UfiSpace S9600-72XC |
72 |
10 |
EdgeCore AGR420 |
74 |
10 |
1.5.2. Consolidated BNG Platforms
| Platform | Number of LAG Interfaces Supported | Number of LAG Members Supported |
|---|---|---|
UfiSpace S9500-22XST |
22 |
10 |
Edgecore CSR320 |
24 |
10 |
UfiSpace S9510-28DC |
NA |
NA |
Edgecore AGR420 |
24 |
10 |
1.5.3. Spine Platforms
| Platform | Max. Number of LAG Interfaces Supported | Number of LAG Members Supported |
|---|---|---|
UfiSpace S9600-32X |
35 |
10 |
EdgeCore AGR400 |
33 |
10 |
1.5.4. L2 Wholesale (L2BSA) Platforms
| Platform | Max. Number of LAG Interfaces Supported | Number of LAG Members Supported |
|---|---|---|
UfiSpace S9500-22XST |
22 |
10 |
Edgecore CSR320 |
24 |
10 |
1.6. Guidelines and Limitations
-
You cannot configure logical interfaces on a LAG member ports.
-
You cannot configure L2X on a LAG member port.
2. Configuring Link Aggregation Groups (LAGs)
2.1. Creating LAG Interfaces
Syntax:
| Attribute | Description |
|---|---|
<name> |
Specifies the name of the LAG interface. The supported LAG interface names: 'lag-1' to 'lag-99'. |
<description> |
Link aggregation interface description |
mode <mode> |
Specifies the LAG mode. The default mode is LACP.
The possible modes are:
|
<minimum-link-count> |
Specify the minimum number of active member links required for the link aggregation interface. |
<member-interface> |
Specify name of the member interface. |
redundancy-session-id |
Specify the value for the redundancy group session ID. Range from 1 to 65535 is allowed. |
system-id |
Specify the MAC address (as system ID) of the device for the link-aggregation interface. |
|
redundancy-session-id, and system-id attributes can only be used when you deploy RBFS in redundancy mode. For information about LAG configuration when deploying RBFS in redundancy mode, see RBFS Redundancy Solution Guide.
|
Example: LAG Interfaces Configuration
supervisor@rtbrick: cfg> show config link-aggregation
{
"rtbrick-config:link-aggregation": {
"interface": [
{
"interface-name": "lag-3",
"mode": "lacp",
"minimum-link-count": 2,
"member-interface": [
{
"member-interface-name": "ifp-0/0/1",
"lacp-mode": "active"
},
{
"member-interface-name": "ifp-0/0/5",
"lacp-mode": "active"
}
{
"member-interface-name": "ifp-0/0/5",
"lacp-mode": "passive"
}
]
}
]
}
}
2.2. Configuring LAG Member Interfaces
You can add member ports to the LAG interface. The command below allows you to bundle multiple physical interfaces with similar properties like speed, MTU, MRU.
Syntax:
| Attribute | Description | ||
|---|---|---|---|
lacp-mode <mode> |
Specifies the LACP mode. The default lacp-mode is |
||
lacp-timeout <timeout-value> |
Specifies the timeout for the LACP session. A long timeout is 90 seconds, while a short is 3 seconds (default is short). Setting the timeout value will instruct the partner at which interval it should send the updates (30 seconds for long timeout, 1 second for short timeout).
|
2.3. Configuring QoS on LAG Interface
RBFS supports QoS at physical interface level for LAG. Users can apply QoS profile at physical interface level through which one common QoS classification can be applied for all traffic on that port, irrespective of the destination logical interface.
The following features are supported:
-
Classification (IEEE-802.1)
-
Remarking (IEEE-802.1)
-
Ingress Policing
-
Egress Policing
For information about configuring the above features, refer the HQoS Configuration Guide.
|
|
|
Syntax:
| Attribute | Description |
|---|---|
<interface> |
Name of the interface |
<class-of-service> |
Specifies the class of service |
Example:
supervisor@rtbrick: cfg> set interface lag-11 class-of-service Retail_profile
supervisor@rtbrick: cfg> commit
supervisor@rtbrick: cfg> show config int lag-11
{
"rtbrick-config:interface": [
{
"name": "lag-11",
"class-of-service": "Retail_profile"
}
]
}
2.4. Configuring L2X on LAG Interface
All forms of L2X that are supported on the regular physical interfaces are supported on LAG. The incoming packet is be matched to a specific L2X profile based on the Cross Connect configuration on the specified LAG interface.
The following match conditions are supported on the LAG interface:
-
Incoming LAG interface without any VLAN
-
Incoming LAG interface with a single VLAN
-
Incoming LAG interface with inner and Outer VLAN
-
Incoming LAG interface with any single VLAN
-
Incoming LAG interface with inner VLAN and any outer VLAN
For information about configuring L2X, see the L2X Configuration Guide.
The following table provides the L2X match action attributes which are supported on LAG interface.
| Attribute | Description |
|---|---|
nexthop6 <nexthop> |
Next-Hop address |
match-type <match-type> |
Match types with which traffic can be matched. |
service-label <service_label> |
Service label value. NOTE: Supported MPLS label values are 0 - 1048575. The reserved MPLS label range is 0 - 15. In RBFS, BGP uses the label range 20000 - 100000. It is recommended to assign label values outside of these reserved ranges to avoid conflicts. |
ingress-vlan-operation <ingress-vlan-action> |
VLAN operation on ingress side outer VLAN |
ingress-outer-vlan <vlan-id> |
Outer VLAN at ingress side |
outgoing_ifp |
Outgoing interface |
vlan_operation |
VLAN operation |
outgoing_outer_vlan1 |
Outgoing outer VLAN |
3. LAG Operational Commands
3.1. Show Commands
3.1.1. Viewing LAG Running Configuration
The following command displays the LAG running configuration on the system.
Syntax:
Example: LAG Running Configuration
supervisor@dev1: cfg> show config link-aggregation
{
"rtbrick-config:link-aggregation": {
"interface": [
{
"interface-name": "lag-4",
"mode": "lacp",
"minimum-link-count": 4,
"member-interface": [
{
"member-interface-name": "ifp-0/0/1",
"lacp-mode": "active",
"lacp-timeout": "long"
},
{
"member-interface-name": "ifp-0/0/4",
"lacp-mode": "active",
"lacp-timeout": "long"
}
]
}
]
}
}
3.1.2. Viewing LAG Information
The following command displays the LAG information.
Syntax:
| Option | Description |
|---|---|
<interface-name> |
Displays information for a specific LAG interface |
detail |
Displays detailed LAG information |
mode <mode> |
Displays information for a LAG mode: |
Example: Viewing LAG Information
supervisor@rtbrick: cfg> show lag detail
Lag interface name: lag-3
Status: Up
Minimum link count: 2
Mode: lacp
Member interface name: ifp-0/0/1
Actor system id: 04:f8:f8:e9:bc:83
Actor key: 107
Partner system id: 04:f8:f8:e9:bf:83
Partner key: 43
Member interface name: ifp-0/0/5
Actor system id: 04:f8:f8:e9:bc:83
Actor key: 107
Partner system id: 04:f8:f8:e9:bf:83
Partner key: 43
3.1.3. Viewing LAG QoS Policer Counters
The following command displays the QoS Policer Counters.
Syntax:
Example 1: QoS policer counter
supervisor@rtbrick: cfg> show qos policer counter
Interface Level Units Total Received Dropped
lag-27 1 Packets 0 0 0
Bytes 0 0 0
lag-27 2 Packets 0 0 0
Bytes 0 0 0
lag-27 3 Packets 0 0 0
Bytes 0 0 0
lag-27 4 Packets 0 0 0
Bytes 0 0 0
lag-28 1 Packets 0 0 0
Bytes 0 0 0
lag-28 2 Packets 0 0 0
Bytes 0 0 0
lag-28 3 Packets 0 0 0
Bytes 0 0 0
lag-28 4 Packets 203 0 203
Bytes 18270 0 18270
lag-29 1 Packets 0 0 0
Bytes 0 0 0
lag-29 2 Packets 0 0 0
Bytes 0 0 0
lag-29 3 Packets 20591812 18850600 1741212
Bytes 21291933608 19491520400 1800413208
lag-29 4 Packets 0 0 0
Bytes 0 0 0
lag-27-egress 1 Packets 0 0 0
Bytes 0 0 0
lag-27-egress 2 Packets 0 0 0
Bytes 0 0 0
lag-27-egress 3 Packets 2011928 2011928 0
Bytes 2116548256 2116548256 0
lag-27-egress 4 Packets 180377 180377 0
Bytes 15574914 15574914 0
lag-28-egress 1 Packets 0 0 0
Bytes 0 0 0
lag-28-egress 2 Packets 0 0 0
Bytes 0 0 0
lag-28-egress 3 Packets 2019661 2019661 0
Bytes 2124683372 2124683372 0
lag-28-egress 4 Packets 178226 178226 0
Bytes 15398532 15398532 0
lag-29-egress 1 Packets 0 0 0
Bytes 0 0 0
lag-29-egress 2 Packets 0 0 0
Bytes 0 0 0
lag-29-egress 3 Packets 1999328 1999328 0
Bytes 2103293056 2103293056 0
lag-29-egress 4 Packets 183300 183300 0
Bytes 15893128 15893128 0
Syntax:
Example 2: QoS policer counter for a specified LAG
supervisor@rtbrick: cfg> show qos policer counter lag-29
Interface Level Units Total Received Dropped
lag-29 1 Packets 0 0 0
Bytes 0 0 0
lag-29 2 Packets 0 0 0
Bytes 0 0 0
lag-29 3 Packets 21241103 19499891 1741212
Bytes 21963300502 20162887294 1800413208
lag-29 4 Packets 0 0 0
Bytes 0 0 0
Example 3
supervisor@rtbrick: cfg> show qos policer counter lag-29-egress
Interface Level Units Total Received Dropped
lag-29-egress 1 Packets 0 0 0
Bytes 0 0 0
lag-29-egress 2 Packets 0 0 0
Bytes 0 0 0
lag-29-egress 3 Packets 2071701 2071701 0
Bytes 2179429452 2179429452 0
lag-29-egress 4 Packets 187300 187300 0
Bytes 16221128 16221128 0
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