BROCADE IP PRIMER

GlossaryVirtual link In OSPF, all areas must be connected to the backbone (area 0). Insome situations, it may be physically inconvenient (or impossible) to directlyconnect an area to the backbone. A virtual link provides a tunnel throughanother area to the backbone.Virtual server In load balancing, this is the “fake” server that is defined on theload balancer. This defines the VIP. The load balancer answers for the virtualserver requests and forwards them to the real servers.VLAN Virtual Local Area Network. This is defined in IEEE 802.1q. A VLANallows an engineer to subdivide a physical switch into smaller Layer 2 broadcastdomains. These subdivisions may also extend to multiple switches andLayer 2 devices. It allows for the formation of a Layer 2 broadcast domain thatis not restricted by the physical dimensions of the network equipment.VLAN Group For ease of configuration, VLAN Groups allow an engineer to bundlemultiple VLANs that have an identical configuration.VLL Virtual Leased Lines. VLL is also known as Pseudo Wire Emulation (PWE).MPLS VLL is a method of providing point-to-point Ethernet /VLAN connectivityover an MPLS domain. The VLL is considered to be a Layer 2 VPN circuit acrossa single Layer 3 backbone.VLSM Variable Length Subnet Mask. This is part of classless network addressing.With a variable-length mask, an engineer may more finely subdividenetwork classes to specific sizes and requirements.VoIP Voice over IP. This is a protocol that provides voice services using an IPnetwork.VRRP Virtual Router Redundancy Protocol. This protocol provides the abilityfor multiple devices to share a single IP address in an active/standby fashion.VRRP-E (Extended) has provided additional features and expandability to theoriginal protocol.VSRP Virtual Switch Redundancy Protocol. This is a protocol that providesLayer 2 redundancy in the event of an entire switch failing. It functions in anactive/standby fashion.WAN Wide Area Network. This describes a network extending across a largergeographic area. This often includes long distance circuits connecting geographically-diverselocations. The Internet is an example of the largest WAN.Well-known port For TCP and UDP ports, there are several ports that havebeen publicly registered for use with specific Layer 7 protocols. For the mostpart, these are port numbers between 1 and 1024.Wildcard mask Where a subnet mask uses a consecutive stream of 1s and0s to define a network portion and host portion of an address, a wildcardmask uses 1s to indicate which bits of an address are changeable. In a wildcardmask, 0s indicate that this bit of the address will not change. The 0s and1s do not have to be consecutive. This method provides a greater deal of flexibility,particularly in configuring ACLs.Brocade IP Primer 421