LAB
Refer to the Exhibit.
The information of the question
You will configure FastEthernet ports 0/12 through 0/24 for users who belong to VLAN 20.
Also, all VLAN and VTP configurations are to be completed in global configuration mode as
VLAN database mode is being deprecated by Cisco. You are required to accomplish the
following tasks:
1. Ensure the switch does not participate in VTP but forwards VTP advertisements received
on trunk ports.
2. Ensure all non-trunking interfaces (Fa0/1 to Fa0/24) transition immediately to the
forwarding state of Spanning-Tree.
3. Ensure all FastEthernet interfaces are in a permanent non-trunking mode.
4. Place FastEthernet interfaces 0/12 through 0/24 in VLAN 20
Answer: See the explanation
Explanation:
switch#conf t
switch(config)#vtp mode transparent
switch(config)#interface range fa0/1 – 24
switch(config-if-range)#switchport mode access
switch(config-if-range)#spanning-tree portfast
switch(config)#interface range fa0/12 – 24
switch(config-if-range)#switchport access vlan 20
switch(config-if-range)#end
switch# copy run startVTP:
The role of the VLAN Trunking Protocol (VTP) is to maintain VLAN configuration consistency
across the entire network. VTP is a messaging protocol that uses Layer 2 trunk frames to
manage the addition, deletion, and renaming of VLANs on a network-wide basis from a
centralized switch that is in the VTP server mode. VTP is responsible for synchronizing
VLAN information within a VTP domain. This reduces the need to configure the same VLAN
information on each switch.
VTP minimizes the possible configuration inconsistencies that arise when changes are
made. These inconsistencies can result in security violations, because VLANs can
crossconnect when duplicate names are used. They also could become internally
disconnected when they are mapped from one LAN type to another, for example, Ethernet to
ATM LANE ELANs or FDDI 802.10 VLANs. VTP provides a mapping scheme that enables
seamless trunking within a network employing mixed-media technologies.
VTP provides the following benefits:
VLAN configuration consistency across the network
Mapping scheme that allows a VLAN to be trunked over mixed media
Accurate tracking and monitoring of VLANs
Dynamic reporting of added VLANs across the network
Plug-and-play configuration when adding new VLANs
There are three different VTP modes:
1. Server:
By default, a Catalyst switch is in the VTP server mode and in the “no management domain”
state until the switch receives an advertisement for a domain over a trunk link or a VLAN
management domain is configured. A switch that has been put in VTP server mode and had
a domain name specified can create, modify, and delete VLANs. VTP servers can also
specify other configuration parameters such as VTP version and VTP pruning for the entire
VTP domain. VTP information is stored in NVRAM.
VTP servers advertise their VLAN configuration to other switches in the same VTP domain,
and synchronize the VLAN configuration with other switches based on advertisements
received over trunk links. When a change is made to the VLAN configuration on a VTP
server, the change is propagated to all switches in the VTP domain. VTP advertisements are
transmitted out all trunk connections, including ISL, IEEE 802.1Q, IEEE 802.10, and ATM
LANE trunks.
2. Client:
The VTP client maintains a full list of all VLANs within the VTP domain, but it does not store
the information in NVRAM. VTP clients behave the same way as VTP servers, but it is not
possible to create, change, or delete VLANs on a VTP client. Any changes made must be
received from a VTP server advertisement.
3. Transparent
VTP transparent switches do not participate in VTP. A VTP transparent switch does not
advertise its VLAN configuration, and does not synchronize its VLAN configuration based on
received advertisements. However, in VTP Version 2, transparent switches do forward VTP
advertisements that the switches receive out their trunk ports. VLANs can be configured on a
switch in the VTP transparent mode, but the information is local to the switch (VLAN
information is not propagated to other switches) and is stored in NVRAM.
To change the VTP mode:
Switch(Config)# vtp mode <Mode>
Or
Switch#vlan database
Switch#vtp <mode>
PortFastA prime reason for enabling PortFast is in cases where a PC boots in a period less than the
30 seconds it takes a switch to put a port into forwarding mode from disconnected state.
Some NICs do not enable a link until the MAC layer software driver is actually loaded. Most
operating systems try to use the network almost immediately after loading the driver, as in
the case of DHCP. This can create a problem because the 30 seconds of STP delay from
listening to Forwarding states begins right when the IOS begins trying to access the network.
In the case of DHCP, the PC will not obtain a valid IP address from the DHCP server. This
problem is common with PC Card (PCMCIA) NICs used in laptop computers. Additionally,
there is a race between operating systems and CPU manufacturers. CPU manufacturers
keep making the chips faster, while at the same time, operating systems keep slowing down,
but the chips are speeding up at a greater rate than the operating systems are slowing
down. As a result, PCs are booting faster than ever. In fact, modern machines are often
finished booting and need to use the network before the STP 30-second delay is over.
Use the spanning-tree portfast global configuration command to globally enable the PortFast
feature on all non-trunking ports.