Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

Bronze

password and vtp transparent mode

Hi every body!

According to my book, if password needs to be configured, it should be configured on all vtp server and client switches in vtp domain.

So should i assume a switch in transparent mode does not need to be configured with the password in order to relay the vtp messages?

thanks a lot!

1 ACCEPTED SOLUTION

Accepted Solutions

Re: password and vtp transparent mode

Hi Sarah,

Yes the switch in transparent mode is simply passing VTP messages out its trunk port unlike the client or server, which process the VTP information. So, it doesnt really matter to the transparent switch whether there's password or not.

Edit:(How switches in VTP domain know if there's password)

By default switches (client and server) sent out VTP summary advertisements. This includes an MD5 digest field. Normally the source sending VTP messages calculates this field based on the header information (VTP domain etc). When VTP password is included, it calculates same hash based on the password as well. The receiving switch performs the same hash and compares the value of MD5 field. If it matches, accept the message else discard it. Now only if the receiving switch has same password configured will it get the same hash. All this clearly indicates that client and servers in VTP process VTP messages. The transparent switch on the otherhand does not process VTP messages but simply fowards it out its trunk ports.

HTH

Lejoe

1 REPLY

Re: password and vtp transparent mode

Hi Sarah,

Yes the switch in transparent mode is simply passing VTP messages out its trunk port unlike the client or server, which process the VTP information. So, it doesnt really matter to the transparent switch whether there's password or not.

Edit:(How switches in VTP domain know if there's password)

By default switches (client and server) sent out VTP summary advertisements. This includes an MD5 digest field. Normally the source sending VTP messages calculates this field based on the header information (VTP domain etc). When VTP password is included, it calculates same hash based on the password as well. The receiving switch performs the same hash and compares the value of MD5 field. If it matches, accept the message else discard it. Now only if the receiving switch has same password configured will it get the same hash. All this clearly indicates that client and servers in VTP process VTP messages. The transparent switch on the otherhand does not process VTP messages but simply fowards it out its trunk ports.

HTH

Lejoe

268
Views
0
Helpful
1
Replies