Should i use vtp pruning

Vtp pruning eligible list remove vlan 6. You can deny a vlan on trunk link by add the particular vlan from vtp pruning eligible list. Vtp pruning eligible list add vlan 6. Great discussion regarding - what is the task really asking us to do? For the CCIE lab, I always felt 3times that the questions were mostly clear, and not ambiguous unless the candidate is weak on a given technology.

In this case, it is clear that you do understand the difference between automatic prune command vs manual vlans allowed. So, I would not get stuck on the wording of this question.

You are already ahead of the game. To answer your question, I guess that I would use the redundant command to future-safe the configuration as someone has already suggested above.

Normally, the lab would hint at the solution with something like do it "automatically or manually " versus mentioning the command prune. And then, you would know exactly what to do, right? In this case, it looks like they are bullet-pointing two different parts of the task. Samer I think VTP pruning does meet all three requirements by itself.

Task 1 and Task 3 are the definition of what VTP pruning does. And basically bullet 1 and bullet 3 are redundant, they both state the same thing. If you encounter a technical issue on the site, please open a support case. Communities: Chinese Japanese Korean. All Rights Reserved. The Cisco Learning Network.

View This Post. Edited by Admin February 16, at AM. He says, you had to use the command switchport trunk allowed vlan 10,20,25,30,40 And he says it is obvious when you look at your show interface trunk command output. He says yours looks like this SW1 sho int trunk! Port Vlans allowed on trunk Po12 Po13 ! Port Vlans allowed on trunk Po1 10,20,25,30,40 Po2 10,20,25,30,40! So here is my question.

So is my vtp pruning working or not? Have I met the lab requirements or not? Top Rated Answers. I will say yes! Make certain that you understand the differences between VTP Version 3 and earlier versions before you alter your network configuration. Understanding VTP Version 3.

VLAN Interaction. Refer to Cisco Technical Tips Conventions for more information on document conventions. Of course, you can have a VTP packet inside Now consider the detail of a VTP packet. But, all VTP packets contain these fields in the header:. The configuration revision number is a bit number that indicates the level of revision for a VTP packet.

This information is used in order to determine whether the received information is more recent than the current version. In order to reset the configuration revision of a switch, change the VTP domain name, and then change the name back to the original name.

By default, Catalyst switches issue summary advertisements in five-minute increments. Summary advertisements inform adjacent Catalysts of the current VTP domain name and the configuration revision number. When the switch receives a summary advertisement packet, the switch compares the VTP domain name to its own VTP domain name. If the name is different, the switch simply ignores the packet.

If the name is the same, the switch then compares the configuration revision to its own revision. If its own configuration revision is higher or equal, the packet is ignored. If it is lower, an advertisement request is sent. The Updater Identity is the IP address of the switch that is the last to have incremented the configuration revision. When you add, delete, or change a VLAN in a Catalyst, the server Catalyst where the changes are made increments the configuration revision and issues a summary advertisement.

While the workstation is totally unaware of our network design and complexity, its broadcast is the reason all our trunks will flood with unwanted traffic, consuming valuable bandwidth!

We don't think describing the above is actually required as the diagram shows all the information we need and we're confident you will agree that we dealing with a big problem:. VTP Pruning as you might have already guessed solves the above problem by reducing the unnecessary flooded traffic described previously.

This is done by forwarding broadcasts and unknown unicast frames on a VLAN over trunk links only if the receiving end of the trunk has ports in that VLAN. Looking at the above diagram you will notice that the Root Catalyst Switch receives a broadcast from Switch 1, but only forwards it out one of it's trunks. This information is then stored by the neighbors and used to decide if flooded traffic from a VLAN should be forwarded to the switch via the trunk port or not.

Note: VTP Pruning is disabled by default on all Cisco Catalyst switches and can be enabled by issuing the " set vtp pruning enable " command. If this command is issued on the VTP Server s of your network, then pruning is enabled for the entire management domain. VTP Pruning configuration and commands are covered in section This default list of pruning eligibility can thankfully be modified to suite your needs but you must first clear all VLANs from the list using the " clear vtp prune-eligible vlan-range " command and then set the VLAN range you wish to add in the prune eligible list by issuing the following command: " set vtp prune-eligible vlan-range " where the 'vlan-range' is the actual inclusive range of VLANs e.

By default, VLANs 2— are eligible for pruning. If the VLANs are configured as pruning-ineligible, the flooding continues as illustrated in our examples. VTP Pruning can in fact be an administrator's best friend in any Cisco powered network, increasing available bandwidth by restricting flooded traffic to those trunk links that the traffic must use to reach the destination devices. At this point, we have also come to the end of the first part of our VLAN presentation.