Vtp And Switch Stacks - Cisco Catalyst 2960 series Configuration Manual

VTP and Switch Stacks

VTP pruning is enabled in the switched network. The broadcast traffic from Switch A is not forwarded to
Switches C, E, and F because traffic for the Red VLAN has been pruned on the links shown (Port 5 on Switch
B and Port 4 on Switch D).
Figure 2: Optimized Flooded Traffic VTP Pruning
Enabling VTP pruning on a VTP server enables pruning for the entire management domain. Making VLANs
pruning-eligible or pruning-ineligible affects pruning eligibility for those VLANs on that trunk only (not on
all switches in the VTP domain).
VTP pruning takes effect several seconds after you enable it. VTP pruning does not prune traffic from VLANs
that are pruning-ineligible. VLAN 1 and VLANs 1002 to 1005 are always pruning-ineligible; traffic from
these VLANs cannot be pruned. Extended-range VLANs (VLAN IDs higher than 1005) are also
pruning-ineligible.
Related Topics
Enabling VTP Pruning, on page 30
VTP and Switch Stacks
The switch supports homogeneous stacking and mixed stacking. Mixed stacking is supported only with
Note
the Catalyst 2960-S switches. A homogenous stack can have up to eight stack members, while a mixed
stack can have up to four stack members. All switches in a switch stack must be running the LAN Base
image.
VTP configuration is the same in all members of a switch stack. When the switch stack is in VTP server or
client mode, all switches in the stack carry the same VTP configuration. When VTP mode is transparent, the
stack is not taking part in VTP.
• When a switch joins the stack, it inherits the VTP and VLAN properties of the active switch.
• All VTP updates are carried across the stack.
Catalyst 2960-X Switch VLAN Configuration Guide, Cisco IOS Release 15.0(2)EX
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Configuring VTP
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