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Sample PVST+ Configuration
The following examples show the PVST+ configuration that you must perform on each peer switch to prevent forwarding loops.
Configure PVST+ on VLT Peers to Prevent Forwarding Loops (VLT Peer 1)
Dell_VLTpeer1(conf)#protocol spanning-tree pvst
Dell_VLTpeer1(conf-pvst)#no disable
Dell_VLTpeer1(conf-pvst)#vlan 1000 bridge-priority 0
Configure PVST+ on VLT Peers to Prevent Forwarding Loops (VLT Peer 2)
Dell_VLTpeer2(conf)#protocol spanning-tree pvst
Dell_VLTpeer2(conf-pvst)#no disable
Dell_VLTpeer2(conf-pvst)#vlan 1000 bridge-priority 4096
Configure both ends of the VLT interconnect trunk with identical PVST+ configurations. When you enable VLT, the show
spanning-tree pvst brief command output displays VLT information (refer to Verifying a VLT Configuration).
DellEMC#show spanning-tree pvst vlan 1000 brief
VLAN 1000
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 0, Address 90b1.1cf4.9b79
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 0, Address 90b1.1cf4.9b79
We are the root of Vlan 1000
Configured hello time 2, max age 20, forward delay 15
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
---------- -------- ---- ------ ----------- ------- -------------------- --------
Po 1 128.2 128 188 FWD(vltI) 0 0 90b1.1cf4.9b79 128.2
Po 2 128.3 128 2000 FWD(vlt) 0 0 90b1.1cf4.9b79 128.3
Te 1/10 128.230 128 2000 FWD 0 0 90b1.1cf4.9b79 128.230
Te 1/13 128.233 128 2000 FWD 0 0 90b1.1cf4.9b79 128.233
Interface
Name Role PortID Prio Cost Sts Cost Link-type Edge
---------- ------ -------- ---- ------- ----------- ------- --------- ----
Po 1 Desg 128.2 128 188 FWD 0 (vltI)P2P No
Po 2 Desg 128.3 128 2000 FWD 0 (vlt) P2P No
Te 1/10 Desg 128.230 128 2000 FWD 0 P2P Yes
Te 1/13 Desg 128.233 128 2000 FWD 0 P2P No
DellEMC#
VLT Sample Configuration
To review a sample VLT configuration setup, study these steps.
1. Configure the VLT domain with the same ID in VLT peer 1 and VLT peer 2.
VLT DOMAIN mode
vlt domain domain id
2. Configure the VLTi between VLT peer 1 and VLT peer 2.
3. You can configure LACP/static LAG between the peer units (not shown).
CONFIGURATION mode
interface port-channel port-channel id
NOTE:
To benefit from the protocol negotiations, Dell Networking recommends configuring VLTs used as facing hosts/
switches with LACP. Ensure both peers use the same port channel ID.
4. Configure the peer-link port-channel in the VLT domains of each peer unit.
INTERFACE PORTCHANNEL mode
channel-member
Virtual Link Trunking (VLT)
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