VTP Advetisement types question

[Deleted User]

Well Forum, Happy New Year!!

Started my CCNP Switch studies last week and I am on Chapter 4 of my Chris Bryant CCNP Switch guide along with my CCNP R&S CBT Nuggets series. So far things are going smoothly but I have 1 question in regards to VTP advertisements.

Per Chris Bryant's guide, Summary advertisements are sent every 5 minutes by VTP servers or upon a change in the vlan database.

Subset advertisements are sent by VTP servers when there is a vlan configuration change.

Just so I am understanding this, for example if I were to go and create a new vlan say vlan 42 (the answer to everything in life haha) then a Summary advertisement would be sent out as the VLAN.dat file has been changed correct?

And for a Subset advertisement if I were to modify an existing vlan say vlan 1 and changed the name of the vlan that would send out a Subset advertisement correct? I may be getting the advertisements confused as I thought that both of those actions would modify the vlan.dat file then wouldn't both types of advertisement be sent out then to the VTP Client?

Thank you for any responses that can help clarify this issue!!


Also have this question as well:

With VTP version 3, it says it supports full range of VLANS 1-4094 where VTP 1 and 2 only supported 1-1005.

With that said, can you use dot1q trunking with VTPv3 and still have it work as I thought it was only for ISL encapsulation? (this may be a dumb question but the wording in this book makes me think it that way)

Chitownjedi

kMastaFlash wrote: »

Well Forum, Happy New Year!!

Started my CCNP Switch studies last week and I am on Chapter 4 of my Chris Bryant CCNP Switch guide along with my CCNP R&S CBT Nuggets series. So far things are going smoothly but I have 1 question in regards to VTP advertisements.

Per Chris Bryant's guide, Summary advertisements are sent every 5 minutes by VTP servers or upon a change in the vlan database. (Correct, In the case of a change in the vlan database, it would need to start advertising itself as a reflection of those new changes, if its advertising the summary of the VTP Domain/configuration, then when a change occurs that would mean it should advertise those changes immediately. Not wait for the next 5 minute time frame to expire. So basically it says "Oh, something just changed, let me send out a new Summary with "those changes," This means the Summary will now have a new revision number... and any other changes to the time-stamp, or information in the followers field to let the clients know how many VTP Subset Advertisements will follow that actually have configuration information like added vlans, deleted or suspended, changed, or things like Vlan MTU parameters)

Subset advertisements are sent by VTP servers when there is a vlan configuration change. (Correct, but the Summary will go out first, and the Subset's will follow like ducklings after its Mother. Each duckling representing a Vlan, and the configuration it should have. So you make a change, and Mother duck (Summary says, "I got some changes for you boys, they're following behind me!) And the Subsequent advertisements will follow (baby ducks - with configuration information for each vlan) if more than one is needed to cover the amount of vlans.)

Just so I am understanding this, for example if I were to go and create a new vlan say vlan 42 (the answer to everything in life haha) then a Summary advertisement would be sent out as the VLAN.dat file has been changed correct? Correct.. Summary Advertisement will have a new Revision number, and include information like the time stamp,update identifier, or how many Subset Advertisements should follow it.)

And for a Subset advertisement if I were to modify an existing vlan say vlan 1 and changed the name of the vlan that would send out a Subset advertisement correct? It would follow the same scenarior as above. (The Summary will go out first, Subset's will follow. Any Changes will cause a Summary to go out first with new revision number and information, and subsets will follow. The Summary can edit the followers field to advertise just how many subsets will follow.)


I may be getting the advertisements confused as I thought that both of those actions would modify the vlan.dat file then wouldn't both types of advertisement be sent out then to the VTP Client? Summary's go out every 5 minutes, and trigger when changes occur (If a change occurs, the Summary will contain revised information in it's headers and how many subset advertisements should follow.) The subset advertisements that follow will contain the vlan configuration information, including any added, deleted, modified, susepended, vlans etc etc...

Thank you for any responses that can help clarify this issue!!


Also have this question as well:

With VTP version 3, it says it supports full range of VLANS 1-4094 where VTP 1 and 2 only supported 1-1005.

With that said, can you use dot1q trunking with VTPv3 and still have it work as I thought it was only for ISL encapsulation? (this may be a dumb question but the wording in this book makes me think it that way) I believe ISL and 802.1Q Support up to 4094 Vlans do to the amount of bits being used in the VLAN-ID field.

Added information within the quotes.

joelsfood

Also, after you finish your test, don't use VTP again.