Example for Configuring MLAG with Rapid PVST+
- Tracy Yang
Analytics
Networking Requirements
As shown in Figure 1, we have implemented MLAG on Switch A and Switch B, the downstream Switch C and Switch D has dual-access to network through Switch A and Switch B respectively.
Rapid PVST+ is deployed in the network to eliminate loops. Devices running rapid PVST+ exchange rapid PVST+ bridge protocol data units (BPDUs) to discover loops in the network and block some ports to prune the network into a loop-free tree network.
Figure1. Example Topology of MLAG with Rapid PVST+
Figure 1 shows the user topology of MLAG with rapid PVST+. Follow the configuration roadmap below to complete the configuration.
- Configure MLAG. Switch A, Switch B and the aggregated port ae1connected to Switch C form an MLAG, link ID is 1; Switch A, Switch B and the aggregated port ae2 connected to Switch D form another MLAG, link ID is 2. MLAG peer-link implements a backup link aggregation group ae3 between Switch A and Switch B to carry MLAG control messages and improve network reliability.
- Configure basic Rapid PVST+ functions to eliminate loops.
Procedure
Configure Switch A, Switch B, Switch C and Switch D according to the networking requirements described above.
Switch A
Step1 Configure the VLANs.
admin@SwitchA# set vlans vlan-id 15 admin@SwitchA# set vlans vlan-id 16 admin@SwitchA# set vlans vlan-id 4088 l3-interface 4088 admin@SwitchA# set interface aggregate-ethernet ae1 family ethernet-switching port- mode trunk admin@SwitchA# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 15 admin@SwitchA# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 16 admin@SwitchA# set interface aggregate-ethernet ae2 family ethernet-switching port-mode trunk admin@SwitchA# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 15 admin@SwitchA# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 16 admin@SwitchA# set interface aggregate-ethernet ae3 family ethernet-switching port-mode trunk admin@SwitchA# set interface aggregate-ethernet ae3 family ethernet-switching vlan members 4088 admin@SwitchA# set interface aggregate-ethernet ae3 family ethernet-switching vlan members 15 admin@SwitchA# set interface aggregate-ethernet ae3 family ethernet-switching vlan members 16 admin@SwitchA# set interface gigabit-ethernet te-1/1/3 family ethernet-switching port-mode trunk admin@SwitchA# set interface gigabit-ethernet te-1/1/3 family ethernet-switching vlan members 15 admin@SwitchA# set interface gigabit-ethernet te-1/1/3 family ethernet-switching vlan members 16
Step2 Configure aggregation interfaces with LACP mode.
admin@SwitchA# set interface aggregate-ethernet ae1 aggregated-ether-options lacp enable true admin@SwitchA# set interface aggregate-ethernet ae2 aggregated-ether-options lacp enable true
Step3 Add member interfaces to the LAG.
admin@SwitchA# set interface gigabit-ethernet ge-1/1/1 ether-options 802.3ad ae1 admin@SwitchA# set interface gigabit-ethernet ge-1/1/2 ether-options 802.3ad ae2 admin@SwitchA# set interface gigabit-ethernet te-1/1/49 ether-options 802.3ad ae3 admin@SwitchA# set interface gigabit-ethernet te-1/1/50 ether-options 802.3ad ae3
Step4 Configure an MLAG domain ID.
admin@SwitchA# set protocols mlag domain 10
NOTE: Currently, only one MLAG domain is allowed to be configured on one MLAG device.
Step5 Specify SwitchA as MLAG Node 0.
admin@SwitchA# set protocols mlag domain 10 node 0
Step6 Configure the peer IP address and peer link port.
admin@SwitchA# set protocols mlag domain 10 peer-ip 10.10.0.2 peer-link ae3
NOTE: Peer-link port should be configured as a LAG port.
Step7 Configure the L3 interface IP address for peer link port on local MLAG peer device.
admin@SwitchA# set l3-interface vlan-interface 4088 address 10.10.0.1 prefix-length 24
Step8 Configure link ID for the MLAG member port.
admin@SwitchA# set protocols mlag domain 10 interface ae1 link 1 admin@SwitchA# set protocols mlag domain 10 interface ae2 link 2
NOTE: The paired MLAG member ports must be bound to the same MLAG link ID.
Step9 Configure MLAG peer VLAN.
admin@SwitchA# set protocols mlag domain 10 peer-ip 10.10.0.2 peer-vlan 4088
Step10 Configure rapid PVST+.
a. Enable spanning tree on Switch A.
admin@SwitchA# set protocols spanning-tree enable true
By default, spanning tree function is enabled.
b. Configure spanning tree mode in rapid PVST+.
admin@SwitchA# set protocols spanning-tree force-version 4
c. Enable rapid PVST+ on VLAN instance.
admin@SwitchA# set protocols spanning-tree pvst vlan 15 enable true admin@SwitchA# set protocols spanning-tree pvst vlan 16 enable true admin@SwitchA# set protocols spanning-tree pvst vlan 4088 enable true
Step11 Commit the configuration.
admin@SwitchA# commit
Switch B
Step1 Configure the VLANs.
admin@SwitchB# set vlans vlan-id 15 admin@SwitchB# set vlans vlan-id 16 admin@SwitchB# set vlans vlan-id 4088 l3-interface 4088 admin@SwitchB# set interface aggregate-ethernet ae1 family ethernet-switching port- mode trunk admin@SwitchB# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 15 admin@SwitchB# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 16 admin@SwitchB# set interface aggregate-ethernet ae2 family ethernet-switching port-mode trunk admin@SwitchB# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 15 admin@SwitchB# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 16 admin@SwitchB# set interface aggregate-ethernet ae3 family ethernet-switching port-mode trunk admin@SwitchB# set interface aggregate-ethernet ae3 family ethernet-switching vlan members 4088 admin@SwitchB# set interface aggregate-ethernet ae3 family ethernet-switching vlan members 15 admin@SwitchB# set interface aggregate-ethernet ae3 family ethernet-switching vlan members 16 admin@SwitchB# set interface gigabit-ethernet te-1/1/3 family ethernet-switching port-mode trunk admin@SwitchB# set interface gigabit-ethernet te-1/1/3 family ethernet-switching vlan members 15 admin@SwitchB# set interface gigabit-ethernet te-1/1/3 family ethernet-switching vlan members 16
Step2 Configure aggregation interfaces with LACP mode.
admin@SwitchB# set interface aggregate-ethernet ae1 aggregated-ether-options lacp enable true admin@SwitchB# set interface aggregate-ethernet ae2 aggregated-ether-options lacp enable true
Step3 Add member interfaces to the LAG.
admin@SwitchB# set interface gigabit-ethernet ge-1/1/1 ether-options 802.3ad ae1 admin@SwitchB# set interface gigabit-ethernet ge-1/1/2 ether-options 802.3ad ae2 admin@SwitchB# set interface gigabit-ethernet te-1/1/49 ether-options 802.3ad ae3 admin@SwitchB# set interface gigabit-ethernet te-1/1/50 ether-options 802.3ad ae3
Step4 Configure an MLAG domain ID.
admin@SwitchB# set protocols mlag domain 10
NOTE: Currently, only one MLAG domain is allowed to be configured on one MLAG device.
Step5 Specify SwitchB as MLAG Node 1.
admin@SwitchB# set protocols mlag domain 10 node 1
Step6 Configure the peer IP address and peer link port.
admin@SwitchB# set protocols mlag domain 10 peer-ip 10.10.0.1 peer-link ae3
NOTE: Peer-link port should be configured as a LAG port.
Step7 Configure the L3 interface IP address for peer link port on local MLAG peer device.
admin@SwitchB# set l3-interface vlan-interface 4088 address 10.10.0.2 prefix-length 24
Step8 Configure link ID for the MLAG member port.
admin@SwitchB# set protocols mlag domain 10 interface ae1 link 1 admin@SwitchB# set protocols mlag domain 10 interface ae2 link 2
NOTE: The paired MLAG member ports must be bound to the same MLAG link ID.
Step9 Configure MLAG peer VLAN.
admin@SwitchB# set protocols mlag domain 10 peer-ip 10.10.0.1 peer-vlan 4088
Step10 Configure rapid PVST+.
a. Enable spanning tree on Switch B.
admin@SwitchB# set protocols spanning-tree enable true
By default, spanning tree function is enabled.
b. Configure spanning tree mode in rapid PVST+.
admin@SwitchB# set protocols spanning-tree force-version 4
c. Enable rapid PVST+ on VLAN instance.
admin@SwitchB# set protocols spanning-tree pvst vlan 15 enable true admin@SwitchB# set protocols spanning-tree pvst vlan 16 enable true admin@SwitchB# set protocols spanning-tree pvst vlan 4088 enable true
Step11 Commit the configuration.
admin@SwitchB# commit
Switch C
Step1 Enable the aggregation interface with LACP mode.
admin@SwitchC# set interface aggregate-ethernet ae1 aggregated-ether-options lacp enable true
Step2 Add the member interfaces to the LAGs.
admin@SwitchC# set interface gigabit-ethernet ge-1/1/1 ether-options 802.3ad ae1 admin@SwitchC# set interface gigabit-ethernet ge-1/1/2 ether-options 802.3ad ae1
Step3 Configure the VLANs.
admin@SwitchC# set vlans vlan-id 15 admin@SwitchC# set vlans vlan-id 16 admin@SwitchC# set interface aggregate-ethernet ae1 family ethernet-switching port-mode trunk admin@SwitchC# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 15 admin@SwitchC# set interface aggregate-ethernet ae1 family ethernet-switching vlan members 16
Step4 Configure rapid PVST+.
a. Enable spanning tree on Switch C.
admin@SwitchC# set protocols spanning-tree enable true
By default, spanning tree function is enabled.
b. Configure spanning tree mode in rapid PVST+.
admin@SwitchC# set protocols spanning-tree force-version 4
c. Enable rapid PVST+ on VLAN instance.
admin@SwitchC# set protocols spanning-tree pvst vlan 15 enable true admin@SwitchC# set protocols spanning-tree pvst vlan 16 enable true
Step5 Commit the configuration.
admin@SwitchC# commit
Switch D
Step1 Enable the aggregation interface with LACP mode.
admin@SwitchD# set interface aggregate-ethernet ae2 aggregated-ether-options lacp enable true
Step2 Add the member interfaces to the LAG ports.
admin@SwitchD# set interface gigabit-ethernet ge-1/1/1 ether-options 802.3ad ae2 admin@SwitchD# set interface gigabit-ethernet ge-1/1/2 ether-options 802.3ad ae2
Step3 Configure the VLANs.
admin@SwitchD# set vlans vlan-id 15 admin@SwitchD# set vlans vlan-id 16 admin@SwitchD# set interface aggregate-ethernet ae2 family ethernet-switching port-mode trunk admin@SwitchD# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 15 admin@SwitchD# set interface aggregate-ethernet ae2 family ethernet-switching vlan members 16
Step4 Configure rapid PVST+.
a. Enable spanning tree on Switch D.
admin@SwitchD# set protocols spanning-tree enable true
By default, spanning tree function is enabled.
b. Configure spanning tree mode in rapid PVST+.
admin@SwitchD# set protocols spanning-tree force-version 4
c. Enable rapid PVST+ on VLAN instance.
admin@SwitchD# set protocols spanning-tree pvst vlan 15 enable true admin@SwitchD# set protocols spanning-tree pvst vlan 16 enable true
Step5 Commit the configuration.
admin@SwitchD# commit
Verify the Configuration
- You can use the run show mlag domain command to check the configuration information of MLAG domain.
# Check MLAG information on Switch A.
admin@SwitchA# run show mlag domain summary Domain ID: 10 Domain MAC: 48:6E:73:FF:00:0a Node ID: 0 ----------------------------------------------------------------------- Peer Link Peer IP Peer Vlan Neighbor Status Config Matched MAC Synced # of Links --------- --------------- --------- --------------- -------------- ---------- -------------- ae3 10.10.10.2 4088 ESTABLISHED Yes Yes 2
# Check MLAG information on Switch B.
admin@SwitchB# run show mlag domain summary Domain ID: 10 Domain MAC: 48:6E:73:FF:00:0a Node ID: 1 ----------------------------------------------------------------------- Peer Link Peer IP Peer Vlan Neighbor Status Config Matched MAC Synced # of Links --------- --------------- --------- --------------- -------------- ---------- ---------- ae3 10.10.10.1 4088 ESTABLISHED Yes Yes 2
- You can use the run show mlag link command to display MLAG link information.
admin@SwitchA# run show mlag link summary # of Links: 2 Link Local LAG Link Status Local Status Peer-Status Config Matched Flood ---- --------- ----------- ------------ ----------- -------------- ----- 1 ae1 IDLE UP UNKNOWN No No 2 ae2 IDLE UP UNKNOWN No No
- You can use the run show mlag consistency-parameter command to display the result of MLAG configuration consistency check, including the global and per MLAG configuration.
admin@SwitchA# run show mlag consistency-parameter link 2
Port Configurations:
-----------------------------------------------------------------
Property Local Value Peer Value Result
----------------------- --------------- --------------- ------
MTU 1514 1514 PASS
Mac Learning Yes Yes PASS
Lag Mode LACP LACP PASS
Native Vlan 1 1 PASS
Port Vlan Mode Trunk Trunk PASS
Spanning-Tree Configurations:
-----------------------------------------------------------------
Property Local Value Peer Value Result
----------------------- --------------- --------------- ------
Mode PVST PVST PASS
BPDU Guard No No PASS
Root Guard No No PASS
Manual Forwarding No No PASS
Link Type P2P P2P PASS
Instance Count 1 1 PASS
Instance Vlan 3
-- Port Priority 128 128 PASS
-- Path Cost 0 0 PASS
admin@SwitchA# run show mlag consistency-parameter summary
Overall : PASS
--------------
Global : PASS
Link 1 : PASS
Link 2 : PASS
MLAG Configurations:
-----------------------------------------------------------------
Property Local Value Peer Value Result
----------------------- --------------- --------------- ------
Domain ID 10 10 PASS
Node ID 0 1 PASS
Peer VLAN 4088 4088 PASS
Link Count 2 2 PASS
Link IDs 1 2 1 2 PASS
Spanning-Tree Configurations:
-----------------------------------------------------------------
Property Local Value Peer Value Result
----------------------- --------------- --------------- ------
Enable PVST PVST PASS
DHCP Snooping Configurations:
-----------------------------------------------------------------
Property Local Value Peer Value Result
----------------------- --------------- --------------- ------
Enable No No PASS
IGMP Snooping Configurations:
-----------------------------------------------------------------
Property Local Value Peer Value Result
----------------------- --------------- --------------- ------
Enable No No PASS
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