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Trunking Network • VLANs are local to each switch's database. • Cisco switches have two Ethernet trunking mechanisms: ISL and IEEE 802. and VLAN information is not passed between switches. • Certain types of switches can negotiate trunk links. • Trunk links provide VLAN identification for frames traveling between switches. • Trunk links must be configured to allow trunking on each end of the link. • Trunks carry traffic from all VLANs to and from the switch by default but can be configured to carry only specified VLAN traffic.1Q. .

. • Option of clear text or hidden password protection. • Configuration option on a per port base instead of only a global scheme. • Support for interaction with VTP Version 1 and VTP Version 2. • Support for a structured and secure VLAN environment (Private VLAN. • Optimized resource handling and more efficient transfer of information. VLAN Trunk Protocol (VTP) • Protection from unintended database overrides during insertion of new switches. or PVLAN). • Support for VLAN numbers up to 4096.

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 .

VTP communicates VLAN existence information between switches. . It works on the Layer 2 of the OSI model.1Q or Cisco ISL trunking protocols. VLAN trunks formed using DTP may utilize either IEEE 802. Neither protocol transmits the data frames that trunks carry. Dynamic Trunking Protocol The Dynamic Trunking Protocol (DTP) is a proprietary networking protocol developed by Cisco Systems for the purpose of negotiating trunking on a link between two VLAN-aware switches. DTP aids with trunk port establishment. DTP should not be confused with VTP. and for negotiating the type of trunking encapsulation to be used. as they serve different purposes.

VTP Components • VTP Domain: It consists of one or more interconnected switches. • All switches in a domain share VLAN configuration details using VTP advertisements. • A router or Layer 3 switch defines the boundary of each domain. VTP Modes . • 3.A switch can be configured in one of . • 2. VTP Advertisements .VTP uses a hierarchy of advertisements to distribute and synchronize VLAN configurations across the network.

VTP Client . change. • Transparent switches do not participate in VTP.Transparent switches forward VTP advertisements to VTP clients and VTP servers. • A switch reset deletes the VLAN information. • A VTP client only stores the VLAN information for the entire domain while the switch is on. • The server is where VLAN can created.• 4. VTP Server .VTP clients function the same way as VTP servers. • 6. VTP Transparent . . • VLANs that are created. or deleted on transparent switches are local to that switch only. • You must configure VTP client mode on a switch.VTP servers advertise the VTP domain VLAN information to other VTP-enabled switches in the same VTP domain. • VTP servers store the VLAN information for the entire domain in NVRAM. or renamed for the domain. • 5. but you cannot create. or delete VLANs on a VTP client. deleted. renamed.

• 7. • Or • It prevents unnecessary flooding of broadcast information from one VLAN across all trunks in a VTP domain. VTP Pruning-VTP pruning increases network available bandwidth by restricting flooded traffic to those trunk links that the traffic must use to reach the destination devices. it reconfigures the trunk link based o which ports are configured with which VLANs . • When VTP pruning is enabled on a network.