Dynamic Trunking Protocol

[Steph1963]

Hi,

1) Can we assume that two ports configured for no-negotiate in different VTP domain can establish a trunk connection.

Nonegotiate (VTP domain A) to nenegotiate (VTP domain B)

Would this configuration would bring to the establishment of a trunk

2) I took the following question from thet Implemting Cisco Switched Networks (Switch) book and I would like to know if referring to the dynamic trunking mode implicitely refers to the Dynamic desirable mode or to the Dynamic auto

Show interface gigabitEthernet 3/9

switchport Name : Gi3/9

Switchport: Enabled

Administrative Mode: Dynamic Auto

Based on the previous show interface command, what statements is true if the link partner (peer switch) is configured for the dynamic trunking mode

a.) The interface cannot negotiate to a trunk port because it is configured for dot1q encapsulation.

b.) Theinterface cannot negotiate to a trunk port because the native VLAN and access VLANs are mismatched

c.) The interface can negotiate to a trunk ort if the peer is configured from the dynamic desirable trunking mode

d.) The interface can negotiate to a trunk port if access VLAN is the same on both side

Answer is C but I am not sure about the real meaning of dynamic trunking mode

Thanks for your help

Stephane

[Peter Paluch · Accepted solution]

Hello Stephane,

You're giving such interesting questions that it's irresistible for me to answer those But I hope I am not getting tiresome by answering all your questions.

1) Can we assume that two ports configured for no-negotiate in different VTP domain can establish a trunk connection. 
Nonegotiate (VTP domain A) to nenegotiate (VTP domain B) 
Would this configuration would bring to the establishment of a trunk 

In nonegotiate mode, the trunk will not be established automatically. However, if both ports are statically configured as trunks using the switchport mode trunk command and using the same encapsulation/tagging protocol, they will be able to form a fully functional trunk - regardless of the VTP domain setting.

I would like to know if referring to the dynamic trunking mode  implicitely refers to the Dynamic desirable mode or to the Dynamic auto

I do not recall seeing such a name - "dynamic trunking mode". I would say that the term is not well defined, as it can be understood to mean any of the dynamic modes, either desirable or auto. I guess that is the meaning of it, after all - because the only opposite, "static trunking mode", is the one with the switchport mode trunk command, and the only way to make a port to be dynamically able to form a trunk is to have it in dynamic desirable/dynamic auto mode.

Best regards,

Peter

[Jon Marshall]

Stephane

I would like to know if referring to the dynamic trunking mode implicitely refers to the Dynamic desirable mode or to the Dynamic auto

It doesn't tell you which one it specifies but you could safely answer C anyway even without the "sh interface" command because the other end is dynamic desirable. Note though if they only told you the other end was dynamic trunking you could not say for sure whether a trunk would form because auto at both ends would not form a trunk.

Jon