VTP Questions 2
Question 1
Explanation
VLAN 1 and VLANs 1002 to 1005 are always pruning-ineligible; traffic from these VLANs cannot be pruned. Extended-range VLANs (VLAN IDs higher than 1005) are also pruning-ineligible. Therefore VTP pruning can be applied only from VLAN 2 to 1001.
Question 2
Explanation
VTP Pruning makes more efficient use of trunk bandwidth by forwarding broadcast and unknown unicast frames on a VLAN only if the switch on the receiving end of the trunk has ports in that VLAN
Question 3
Explanation
In Client mode we cannot create VLAN and Switch1 does not have any trunk links so it cannot receive any VTP updates. There is no answer with configure trunk links so we have to choose the solution “change VTP mode to server and enable 802.1q”. But this is a dangerous solution because this switch can “update” other switches with its VLAN database via VTP.
Question 4
Explanation
From the output above we see Switch Company A cannot receive VTP updates from Switch Company B. Therefore we should check the trunking links connecting two switches. Manually force trunking may be a good solution.
Question 5
Explanation
VTP Pruning makes more efficient use of trunk bandwidth by forwarding broadcast and unknown unicast frames on a VLAN only if the switch on the receiving end of the trunk has ports in that VLAN
Question 6
Explanation
VLANs 2–1000 are eligible for pruning but VLAN 1 has a special meaning because it is normally used as a management VLAN and is not eligible for pruning. The only way we can remove VLAN 1 is through the “switchport trunk allowed vlan remove 1” command. But even when you remove VLAN 1 from a trunk port, the interface continues to sent and receive management traffic, for example, Cisco Discovery Protocol (CDP), Port Aggregation Protocol (PAgP), Link Aggregation Control Protocol (LACP), DTP, and VTP in VLAN 1.
A good thing of clearing VLAN 1 is user data cannot travel via this VLAN anymore. BPDU traffic is also banned on this VLAN.
Note: The Cisco IOS-based Catalyst 2900XL/3500XL switches do not allow you to clear VLAN 1 from a trunk; however, the Catalyst 2950/3550, Cisco IOS 4000/4500, and native IOS 6000/6500 switches allow you to clear VLAN 1.
Question 7
Question 8
Explanation
If the revision number of the new switch is higher than other switches in the same VTP domain then it will overwrite other switches’ VLAN databases even if the new switch operates in VTP Client mode. So we should set the VTP mode of the new switch to Transparent (which will also reset its Revision Number to 0) before plugging to our network.
Question 9
Explanation
VTPv3 supports for extended VLAN range (VLANs 1006 to 4094). VTP versions 1 and 2 only supports VLANs 1 to 1005. If extended VLANs are configured, we cannot convert from VTP version 3 to version 1 or 2.
Question 10
Explanation
These switches are running VTPv1 so they cannot share the MST configuration with each other (only VTPv3 supports MST). Therefore in order to share the same MST with DSW2, DSW1 must be manually configured with the same region name, revision number and VLAN-to-instance mapping with DSW2.
SW01#show vtp status
VTP Version : running VTP2
Configuration Revision : 2
Maximum VLANs supported locally : 255
Number of existing VLANs : 9
VTP Operating Mode : Server
VTP Domain Name : POALAB
VTP Pruning Mode : Disabled
VTP V2 Mode : Enabled
VTP Traps Generation : Disabled
MD5 digest : 0xB8 0xAA 0xB2 0x5B 0x24 0xB7 0x9A 0xA1
Configuration last modified by 0.0.0.0 at 3-5-93 05:28:17
Local updater ID is 10.0.0.1 on interface Vl100 (lowest numbered VLAN interface found)
SW01(config-vlan)#end
% Failed to create VLANs 2000
Extended VLAN(s) not allowed in current VTP mode.
%Failed to commit extended VLAN(s) changes.
The configurations of VLAN IDs 1 to 1005 are always saved in the VLAN database (vlan.dat file). If the VTP mode is transparent, they are also saved in the switch running configuration file. You can enter the copy running-config startup-config privileged EXEC command to save the configuration in the startup configuration file. To display the VLAN configuration, enter the show vlan privileged EXEC command.
When you save VLAN and VTP information (including extended-range VLAN configuration information) in the startup configuration file and reboot the switch, the switch configuration is selected as follows:
•If the VTP mode is transparent in the startup configuration, and the VLAN database and the VTP domain name from the VLAN database matches that in the startup configuration file, the VLAN database is ignored (cleared), and the VTP and VLAN configurations in the startup configuration file are used. The VLAN database revision number remains unchanged in the VLAN database.
•If the VTP mode or domain name in the startup configuration does not match the VLAN database, the domain name and VTP mode and configuration for the first 1005 VLANs use the VLAN database information.
•In VTP versions 1 and 2, if VTP mode is server, the domain name and VLAN configuration for only the first 1005 VLANs use the VLAN database information. VTP version 3 also supports VLANs 1006 to 4094.
I don’t see anything about greater than 1005 in server mode. I only see if switch is in VTPv3 then greater than 1005 is used but question does not state what vtpmode there is.
I did not have this question on my test so I am not sure but doesn’t seem t be both B/C
To make clear:
•In VTP versions 1 and 2, if VTP mode is server, the domain name and VLAN configuration for only the first 1005 VLANs use the VLAN database information. VTP version 3 also supports VLANs 1006 to 4094.
Again, I don’t see where the question tells about version, but just states mode is server. But we can assume that this is all 3 versions. Also, no where does it say to use vlans > 1005 in the startup config file…it says vtpv3 in server mode uses vlans >1005 from the Vlan database. It says that VTP in server mode version 1 and 2 uses first 1005 vlans from database.