is VTP pruning a recommended way ?

[Sulaiman Ejaz]

why we use vtp pruning? and if we do then is it recommended to use ?

[Evgeniy Prichinin]

VTP pruning makes more efficient use of trunk bandwidth by reducing  unnecessary flooded traffic. Broadcast and unknown unicast frames on a  VLAN are forwarded over a trunk link only if the switch on the receiving  end of the trunk has ports in that VLAN.

[subhojithalder198]

HI,

As per cisco design guideline,

Manually prune unused VLANs to avoid broadcast propagation (commonly done on

the distribution switch).

Br/Subhojit

[Sulaiman Ejaz]

and is it recommended ? doesn't it generates extra traffic ?

[Evgeniy Prichinin]

it depend on your topology.

[johnlloyd_13]

hi,

in my professional experience, i haven't seen VTP pruning being used.

we usually "prune" unwanted VLAN traffic is by using the switchport trunk allowed vlan x command on a trunk.

[Sulaiman Ejaz]

Thankyou john

[Peter Paluch]

Sulaiman,

The basic idea behind the VTP Pruning is good. However, the implementation of VTP Pruning has often proved to be fragile and unstable, and sometimes led to unpredictable outages in network connectivity. Even here on CSC, there is a number of incidents documented where networks suddenly became partitioned for no obvious reason, and the problem was traced back to the VTP Pruning. Deactivating it "miracuously" solved the issues.

So personally, I do not recommend running VTP Pruning. As I said earlier, I like the idea VTP Pruning tries to accomplish. However, the implementation has not proven to be robust enough.

Best regards,

Peter