Search results
Results From The WOW.Com Content Network
VLANs operate at the data link layer of the OSI model. Administrators often configure a VLAN to map directly to an IP network, or subnet, which gives the appearance of involving the network layer. Generally, VLANs within the same organization will be assigned different non-overlapping network address ranges. This is not a requirement of VLANs.
This is known as inter-VLAN routing. On layer-3 switches it is accomplished by the creation of layer-3 interfaces (SVIs). Inter VLAN routing, in other words routing between VLANs, can be achieved using SVIs. [1] SVI or VLAN interface, is a virtual routed interface that connects a VLAN on the device to the Layer 3 router engine on the same device.
Cisco Inter-Switch Link (ISL) is a Cisco proprietary link layer protocol that maintains VLAN information in Ethernet frames as traffic flows between switches and routers, or switches and switches. [1] ISL is Cisco's VLAN encapsulation protocol and is supported only on some Cisco equipment over the Fast and Gigabit Ethernet links.
There is a need to preserve IP addressing. With Private VLANs, all Secondary VLANs can share the same IP subnet. Overcome license fees for number of supported VLANs per firewall. [5] There is a need for more than 4095 segregated networks. With Isolated VLAN, there can be endless number of segregated networks. [6]
Before the IEEE published a Spanning Tree Protocol standard for VLANs, a number of vendors who sold VLAN-capable switches developed their own Spanning Tree Protocol versions that were VLAN capable. Cisco developed, implemented and published the Per-VLAN Spanning Tree (PVST) proprietary protocol using its own proprietary Inter-Switch Link (ISL ...
IEEE 802.1Q, often referred to as Dot1q, is the networking standard that supports virtual local area networking (VLANs) on an IEEE 802.3 Ethernet network. The standard defines a system of VLAN tagging for Ethernet frames and the accompanying procedures to be used by bridges and switches in handling such frames.
On Cisco Devices, VTP (VLAN Trunking Protocol) maintains VLAN configuration consistency across a single Layer 2 network. VTP uses Layer 2 frames to manage the addition, deletion, and renaming of VLANs from switches in the VTP client mode. VTP is responsible for synchronizing VLAN information within a VTP domain and reduces the need to configure ...
To enable the forwarding of User Datagram Protocol (UDP) broadcasts, including BOOTP, received on an interface, use the ip helper-address command in interface configuration mode. To disable the forwarding of broadcast packets to specific addresses, use the no form of this command.