What configuration is needed to span a user defined Virtual LAN (VLAN) between two or more switches?
- A VTP domain must be configured.
- VTP pruning should be enabled.
- The VTP mode of operation should be server.
- A trunk connection should be set up between the switches.
To span a user defined VLAN between two or more switches, a trunk connection must be established. Trunk connections can carry frames for multiple VLANs. If the link between switches is not trunked, by default only VLAN 1 information will be switched across the link.
A VLAN trunking protocol (VTP) domain is not necessary to span VLANs across multiple switches. VTP is used to have consistent VLAN configuration throughout the domain.
VTP pruning is used to detect whether a trunk connection is carrying unnecessary traffic for VLANs that do not exist on downstream switches. By default, all trunk connections carry traffic from all VLANs in the management domain. However, a switch does not always need a local port configured for each VLAN. In such situations, it is not necessary to flood traffic from VLANs other than the ones supported by that switch. VTP pruning enables switching fabric to prevent flooding traffic on trunk ports that do not need it.
VTP server mode is not required for a server to span multiple switches. In VTP server mode of operation, VLANs can be created, modified, deleted, and other VLAN configuration parameters can be modified for the entire VTP domain. VTP messages are sent over all trunk links, and configuration changes are propagated to all switches in the VTP domain.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot VLANs (normal/extended range) spanning multiple switches