Example of MLAG Configuration

Below is an example of how to configure an MLAG. Simple MLAG Configuration shows a finished MLAG network.

Create the Inter-Switch Connection (ISC).
Description: The ISC provides an out-of-band IP communications path between the two MLAG peer switches to exchange keep-alive packets and to checkpoint various state information between switches.

On the “Left” BlackDiamond 8800 switch:
```
enable sharing 2:1 group 2:1,3:1
create vlan isc
config vlan isc tag 3000
config vlan isc add port 2:1 tag
config vlan isc ipaddress 1.1.1.1/24
```
On the “Right” BlackDiamond 8800 switch:
```
enable sharing 2:1 group 2:1,3:1
create vlan isc
config vlan isc tag 3000
config vlan isc add port 2:1 tag
config vlan isc ipaddress 1.1.1.2/24
```
Create the MLAG peer and associate the peer switch's IP address.
Description: By creating an MLAG peer you associate a peer name that can be associated with the peer switch's IP address and other peer configuration properties. The peer is then bound to each individual MLAG port group.

On the “left” BlackDiamond 8800 switch:
```
create mlag peer "rightBD8K"
config mlag peer “rightBD8K” ipaddress 1.1.1.2
```
On the “right” BlackDiamond 8800 switch:
```
create mlag peer “leftBD8K”
config mlag peer "leftBD8K" ipaddress 1.1.1.1
```
Create the MLAG port groups.
Tip
At this point, you could use orchestration mode to allow you to checkpoint all commands issued on the one switch to its MLAG peer. For more information about, MLAG orchestration, see Orchestration Mode for Checkpointing MLAG Port Configuration.

Description: Creates an MLAG port group by specifying the local switch's port, the MLAG peer switch, and an "mlag-id" which is used to reference the corresponding port on the MLAG peer switch. The specified local switch's port can be either a single port or a load share master port.

On the “left” BlackDiamond 8800 switch:
```
enable mlag port 1:1 peer "rightBD8K" id 1
enable mlag port 1:2 peer "rightBD8K" id 2
```
On the “right” BlackDiamond 8800 switch:
```
enable mlag port 1:2 peer "leftBD8K" id 1
enable mlag port 1:1 peer "leftBD8K" id 2
```

Verify MLAG peers and ports are operational.

Description: After MLAG groups are configured, you can verify the connections via the show mlag peer and show mlag ports commands. Be sure to note the peer status, the Local Link State, and the Remote Link status.

On the “left” BlackDiamond 8800 switch:

BD-8810.5 # show mlag peer
Multi-switch Link Aggregation Peers:
MLAG Peer         : leftBD8k
VLAN              : isc             Virtual Router    : VR-Default
Local IP Address  : 1.1.1.2         Peer IP Address   : 1.1.1.1
MLAG ports        : 2               Tx-Interval       : 1000 ms
Checkpoint Status : Up              Peer Tx-Interval  : 1000 ms
Rx-Hellos         : 184             Tx-Hellos         : 184
Rx-Checkpoint Msgs: 12              Tx-Checkpoint Msgs: 12
Rx-Hello Errors   : 0               Tx-Hello Errors   : 0
Hello Timeouts    : 1               Checkpoint Errors : 0
Up Time           : 0d:0h:0m:10s    Peer Conn.Failures: 1

BD-8810.3 # show mlag ports
Local  
                                                            Local  Remote
MLAG        Local   Link     Remote                 Peer    Fail   Fail
Id          Port    State    Link    Peer           Status  Count  Count
=========================================================================
1       1:1   A        Up          rightBD8K        Up          0      0
2       1:2   A        Up          rightBD8K        Up          0      0
=========================================================================
Local Link State: A - Active, D - Disabled, R - Ready, NP - Port not present
Remote Link     : Up - One or more links are active on the remote switch,
Down - No links are active on the remote switch,
N/A - The peer has not communicated link state for this MLAG port
Number of Multi-switch Link Aggregation Groups  : 2
Convergence control                             : Fast

On the “right” BlackDiamond 8800 switch:

BD-8810.3 # show mlag peer
Multi-switch Link Aggregation Peers:
MLAG Peer         : rightBD8k
VLAN              : isc             Virtual Router    : VR-Default
Local IP Address  : 1.1.1.1         Peer IP Address   : 1.1.1.2
MLAG ports        : 2               Tx-Interval       : 1000 ms
Checkpoint Status : Up              Peer Tx-Interval  : 1000 ms
Rx-Hellos         : 167             Tx-Hellos         : 167
Rx-Checkpoint Msgs: 12              Tx-Checkpoint Msgs: 12
Rx-Hello Errors   : 0               Tx-Hello Errors   : 0
Hello Timeouts    : 1               Checkpoint Errors : 0
Up Time           : 0d:0h:0m:7s     Peer Conn.Failures: 1

BD-8810.5 # show mlag ports
Local                                               Local   Remote
MLAG            Local   Link     Remote                     Peer    Fail    FailId      
                Port    State    Link    Peer               Status  Count   Count
================================================================================
2       1:1     A        Up              leftBD8K           Up          0       0
1       1:2     A        Up              leftBD8K           Up          0       0
================================================================================
Local Link State: A - Active, D - Disabled, R - Ready, NP - Port not present
Remote Link     : Up - One or more links are active on the remote switch,
Down - No links are active on the remote switch,
N/A - The peer has not communicated link state for this MLAGport
Number of Multi-switch Link Aggregation Groups  : 2
Convergence control                             : Fast

Add ISC port to VLAN.

Description: The ISC port must be added as a member port for any VLAN that has MLAG member ports.
```
create vlan "xyz"
```
On the “left” BlackDiamond 8800 switch:
```
configure vlan "xyz" add port 1:1, 2:1 tagged
```
On the “right” BlackDiamond 8800 switch:
```
configure vlan "xyz" add port 1:2, 2:1 tagged
```
Simple MLAG Configuration, shows a basic MLAG network. Two-tier MLAG Network shows a network with back-to-back aggregation. There is one MLAG configured on the BlackDiamond switches and three configured on the ExtremeSwitching switches.

Two-tier MLAG Network