Dell Networking VLT configuration

Spanning Tree on the VLT peer switches

Spanning tree is enabled by default and recommended to prevent loops in VLT domain. RPVST+ (default) and RSTP modes are supported on VLT ports.

OS10# configure terminal 
OS10(config)# spanning-tree mode rstp [or] rapid-pvst

Create a VLT Domain and Configure the VLT interconnect (VLTi)

OS10# configure terminal	Enter configuration mode.
OS10(config)# interface range ethernet 1/1/1-1/1/2	Enter interface configuration mode
OS10(conf-range-eth1/1/1-1/1/2)# no switchport	Remove switchport from the VLTi ports.
OS10(config)# vlt-domain 1	Create a VLT domain by configuring the same domain ID on each peer.
OS10(conf-vlt-1)# discovery-interface ethernet 1/1/1	Set the VLTi interfaces.
OS10(conf-vlt-1)# discovery-interface ethernet 1/1/2	Set the VLTi interfaces.

The "VLT time interval" optional is not covered in this article. Changing the VLT time interval is based on design requirements. In certain environments, the timer may need to be increased to ensure routing protocols come up before VLT converges to prevent possible outages.

Configure the VLT Priority, VLT MAC Address, and VLT Backup Link

OS10# configure terminal	Enter configuration mode.
OS10(config)# vlt-domain 1	Enter VLT domain configuration mode.
OS10(conf-vlt-1)# backup destination 1.1.1.2 (primary peer) OS10(conf-vlt-1)# backup destination 1.1.1.1 (secondary peer)	Specify the management IP address of the peer switch. This sets up the Heartbeat that monitors system up.

Each VLT domain in the network must use a separate unique mac address.

Configure a LAG for a connected end device

The following example uses ethernet 1/1/10 on both VLT peers, in a LACP Port-Channel, to connect to one end device. 

OS10# configure terminal	Enter configuration mode.
OS10(config)# interface port-channel 5	Specify the LAG to the end device. Use the same LAG number on both peers.
OS10(conf-if-po-5)# vlt-port-channel 5	Specify the LAG as VLT.
OS10(conf-if-po-5)# exit	Exit
OS10(config)# interface ethernet 1/1/10	Enter interface configuration mode.
OS10(conf-if-eth1/1/10)# channel-group 5 mode active	Specify the LAG on the port.

Verify the port channel is Up:

OS10# show vlt 1 vlt-port-detail
VLT port channel ID : 5
VLT Unit ID Port-Channel Status Configured ports Active ports
----------------------------------------------------------------------------------
*1 port-channel5 up 1 1
2 port-channel5 up 1 1

Verifying and Monitoring

OS10# show vlt 1
Domain ID : 1
Unit ID : 1
Role : primary
Version : 1.0
Local System MAC address : 90:b1:1c:f4:99:93
VLT MAC address : 00:11:22:33:44:55
IP address : fda5:74c8:b79e:1::1
Delay-Restore timer : 1000 seconds
Peer-Routing : Disabled
Peer-Routing-Timeout timer : 0 seconds
VLTi Link Status
port-channel1000 : up

VLT Peer Unit ID System MAC Address Status IP Address Version
--------------------------------------------------------------------------
2 90:b1:1c:f4:bc:0a up fda5:74c8:b79e:1::2 1.0


OS10# show vlt 1 mismatch
Peer-routing mismatch:
No mismatch
VLAN mismatch:
No mismatch
VLT VLAN mismatch:
No mismatch


OS10# show running-configuration vlt
!
vlt domain 1
discovery-interface ethernet 1/1/1
discovery-interface ethernet 1/1/2
primary-priority 4096
vlt-mac 00:11:22:33:44:55
backup destination 1.1.1.2
!
interface port-channel 5
vlt-port-channel 5

Delete startup configuration on first switch

Dell>enable

Dell#delete startup-config

Proceed to delete startup-config [confirm yes/no]yes

Dell#reload

System configuration has been modified. Save? [yes/no]no

Proceed with reload [confirm yes/no]yes

Configure stack on the first switch

Dell>enable

After the startup configuration is deleted, the factory default Enable mode password is calvin.

Dell#configure

Dell(conf)#stack-unit 1 priority 1

Dell(conf)#stack-unit 1 stack-group 12

Dell(conf)#stack-unit 1 stack-group 13

Dell(conf)#exit

Dell#copy running-config startup-config

Dell#reload

Configure stack on the second switch

Dell>enable

Dell#stack-unit 1 renumber 2

Note: After confiming configuration change, the switch will need to reboot.

Dell#configure

Dell(conf)#stack-unit 2 priority 1

Dell(conf)#stack-unit 2 stack-group 12

Dell(conf)#stack-unit 2 stack-group 13

Dell(conf)#exit

Dell#copy running-config startup-config

Dell#reload

Verify stack configuration

From the first switch (Master) CLI, confirm that the stack has formed:

Dell#show redundancy

Dell#show boot system stack-unit all