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Example for Configuring MLAG with MSTP

Example for Configuring MLAG with MSTP

Owned by Tracy Yang (Unlicensed)
Dec 05, 2019

Networking Requirements

In Figure 1, we have implemented MLAG on SwitchA and SwitchB, the downstream SwitchC and SwitchD have dual-access to network through SwitchA and SwitchB respectively.

This topology uses MSTP to prevent link loops, VLAN 15 is mapped to MSTI-1 and VLAN 16 is mapped to MSTI-2. The entire topology belongs to only one MSTP domain named region1.

Figure 1 MLAG Topology

Procedure

Configuring MLAG on SwitchA

Step1         Configure an aggregation interface with LACP mode.

    admin@XorPlus# set interface aggregate-ethernet ae1 aggregated-ether-options lacp enable true

    admin@XorPlus# set interface aggregate-ethernet ae2 aggregated-ether-options lacp enable true

    admin@XorPlus# set interface aggregate-ethernet ae3

Step2         Add member interfaces to a LAG.

    admin@XorPlus# set interface gigabit-ethernet ge-1/1/1 ether-options 802.3ad ae1

   admin@XorPlus# set interface gigabit-ethernet ge-1/1/2 ether-options 802.3ad ae2

   admin@XorPlus# set interface gigabit-ethernet te-1/1/49 ether-options 802.3ad ae3

   admin@XorPlus# set interface gigabit-ethernet te-1/1/50 ether-options 802.3ad ae3

Step3        Configure VLAN.

   admin@XorPlus# set vlans vlan-id 15

   admin@XorPlus# set vlans vlan-id 16

   admin@XorPlus# set vlans vlan-id 4094 l3-interface 4094

   admin@XorPlus# set interface aggregate-ethernet ae1 family ethernet-switching port-mode trunk

   admin@XorPlus# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 15

   admin@XorPlus# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 16

   admin@XorPlus# set interface aggregate-ethernet ae2 family ethernet-switching port-mode trunk

   admin@XorPlus# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 15

   admin@XorPlus# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 16

   admin@XorPlus# set interface aggregate-ethernet ae3 family ethernet-switching port-mode trunk

   admin@XorPlus# set interface aggregate-ethernet ae3 family ethernet-switching vlan members 15

   admin@XorPlus# set interface aggregate-ethernet ae3 family ethernet-switching vlan members 16

Step4        Configure the L3 interface IP address.

                  admin@XorPlus# set vlan-interface interface vlan4094 vif 4094 address 10.10.0.1 prefix-length 24

Step5        Configure MLAG domain ID.

   admin@XorPlus# set interface aggregate-ethernet ae1 aggregated-ether-options mlag domain-id 1

   admin@XorPlus# set interface aggregate-ethernet ae2 aggregated-ether-options mlag domain-id 2

Step6        Configure the peer IP address and the peer-link for the MLAG peer.

   admin@XorPlus# set interface aggregate-ethernet ae1 aggregated-ether-options mlag peer 10.10.0.2 peer-link ae3

    admin@XorPlus# set interface aggregate-ethernet ae2 aggregated-ether-options mlag peer 10.10.0.2 peer-link ae3

Step6        Configure system ID for LACP negotiation.

                  admin@XorPlus# set interface mlag system-id 00:B0:BC:00:00:00

Step8         Configure a static ARP entry for peer-link interface.

   admin@XorPlus# set interface gigabit-ethernet ae3 static-ethernet-switching mac-address A0:34:44:32:9C:23 vlan 4094

   admin@XorPlus# set protocols arp interface vlan4094 address 10.10.0.2 mac-address A0:34:44:32:9C:23

NOTE:

PICA8 recommends configuring a static ARP for peer-link interface to prevent ARP entry of the peer-link interface from being modified by ARP attack packets.

 

Configuring MLAG on SwitchB

 Configurations of MLAG on SwitchB are similar to SwitchA.

Configuring LAG on SwitchC

Step1         Configure an aggregation interface with LACP mode.

    admin@XorPlus# set interface aggregate-ethernet ae1 aggregated-ether-options lacp enable true

Step2          Add member interfaces to a LAG.

    admin@XorPlus# set interface gigabit-ethernet ge-1/1/1 ether-options 802.3ad ae1

    admin@XorPlus# set interface gigabit-ethernet ge-1/1/2 ether-options 802.3ad ae1 

Step3         Configure VLAN. 

    admin@XorPlus# set vlans vlan-id 15 

    admin@XorPlus# set vlans vlan-id 16

    admin@XorPlus# set interface aggregate-ethernet ae1 family ethernet-switching port-mode trunk 

    admin@XorPlus# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 15

    admin@XorPlus# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 16

Configuring LAG on SwitchD

Step1         Configure an aggregation interface with LACP mode.

    admin@XorPlus# set interface aggregate-ethernet ae2 aggregated-ether-options lacp enable true

Step2          Add member interfaces to a LAG.

    admin@XorPlus# set interface gigabit-ethernet ge-1/1/1 ether-options 802.3ad ae2

    admin@XorPlus# set interface gigabit-ethernet ge-1/1/2 ether-options 802.3ad ae2 

Step3         Configure VLAN.

    admin@XorPlus# set vlans vlan-id 15 

    admin@XorPlus# set vlans vlan-id 16

    admin@XorPlus# set interface aggregate-ethernet ae2 family ethernet-switching port-mode trunk 

    admin@XorPlus# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 15

    admin@XorPlus# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 16

Configuring MSTP on SwitchA

Step1         Enable spanning tree on SwitchA.

                   admin@XorPlus# set protocols spanning-tree enable true

    By default, spanning tree function is enabled.

Step2         Configure spanning tree mode in MSTP.

    admin@XorPlus# set protocols spanning-tree force-version 3

Step3         Configure spanning tree MSTI.

                   admin@XorPlus# set protocols spanning-tree mstp msti 1

           admin@XorPlus# set protocols spanning-tree mstp msti 2

Step4         Configure VLAN for each MSTI.

                   admin@XorPlus# set protocols spanning-tree mstp msti 1 vlan 15

                   admin@XorPlus# set protocols spanning-tree mstp msti 2 vlan 16

Step5         Configure MSTP domain named region1.

                   admin@XorPlus# set protocols spanning-tree mstp configuration-name region1

Step6         Commit the configuration.

                   admin@XorPlus# commit

Configuring MSTP on SwitchB, SwitchC, and SwitchD

 Configuration of MSTP on SwitchB, SwitchC, and SwitchD are similar to SwitchA.

Verify the Configuration

 

•  You can use the run show spanning-tree mstp bridge command to view the bridge information of MSTP.

admin@XorPlus# run show spanning-tree mstp bridge

Bridge Spanning Tree Parameters

Enabled Protocol: MSTP

Root ID: 32768.08:9e:01:39:1a:fe

External Root Path Cost: 0

CIST Regional Root ID: 32768.08:9e:01:39:1a:fe

Root Port: ae1

CIST Internal Root Path Cost: 1000

Hello Time: 2

Maximum Age: 20

Forward Delay: 15

Remaining Hops: 19

Bridge Configuration Name: region1

Bridge Configuration Digest: ac36177f50283cd4b83821d8ab26de62

Msti 1 Member VLANs:

15

Msti 2 Member VLANs:

16

Number of Topology Changes: 14

Time Since Last Topology Change: 0 days 00:02:49

Local Parameters

Bridge ID: 32768.18:2a:81:23:9f:00

Hello Time: 2

Maximum Age: 20

Forward Delay: 15

Remaining Hops: 20


•  You can use the run show spanning-tree mstp interface command to view the interface information of MSTP.

admin@Xorplus# run show spanning-tree mstp interface

MSTP Spanning Tree Interface Status for instance 0

Interface   Port ID  Designated  Designated Bridge    Ext Path   Int Path   State       Role

                              Port ID         ID                              Cost          Cost

----------    ---------    ----------       -----------------------       ---------      ---------  ----------  ---------------

ae1      128.79     128.69   32768.08:9e:01:39:1a:fe   1000   1000    FORWARDING  ROOT

ae2      128.80     128.70   32768.18:2a:81:23:9f:00   1000   1000    FORWARDING  ROOT

ae3      128.81     128.71   32768.08:9e:01:39:1a:fe   1000   1000    FORWARDING  MSTP DISABLED

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