437 unannounced transfers, 541 vlan access-map command, 429 Index vlan command, 35 troubleshooting, 567-570 vlan database command, 31 vPC (virtual Port-Channel) vlan filter command, 430 adding, 77-80 VLAN maps, 427, 429-430 FEX and, 294 VLAN Trunking Protocol (see VTP) functionality, 75 VLANs (virtual LANs) HSRP and, 189 broadcasts and, 8 initial configuration, 76 configuring, 29-36 network design considerations, 642 configuring SVIs and, 223 Nexus support, 294-300 connecting, 25-29 VSS comparison, 76 defined, 25 vpc role priority command, 296 documenting, 633 VPN concentrators, 167 in ecommerce website designs, 646 VPNs (Virtual Private Networks) multilayer switches and, 221 point-to-point, 167 network design considerations, 642 remote access and, 167 small office VoIP example, 533-534 security considerations, 515 SPAN considerations, 332-335 tunnel support, 167 spanning tree and, 91 VRF (Virtual Routing and Forwarding), 115- tagging considerations, 39 117, 207, 281-283 voice VLAN and, 336-337 vrf context command, 115 VLSM (Variable Length Subnet Masks), 132, vrf member command, 115 VRRP (Virtual Router Redundancy Protocol), voice activity detection (VAD), 563 voice ports, 542 vsh command (NX-OS), 278 voice translation-profile command, 564 VSL (virtual switch link), 256 voice VLAN, 336-337 VSS (Virtual Switching System) VoIP (Voice over IP) best practices, 263 additional information, 523 failover commands, 261 call quality and, 524 functionality, 75 common issues, 530-531 installing, 253-259 functionality, 523-525 miscellaneous commands, 262 jitter issues, 531 recommended commands, 259-261 latency issues, 530 supervisor models and, 240 packet loss issues, 531, 575 vPC comparison, 76 protocols supported, 525-527 VSS clusters, 295 small office example VTP (VLAN Trunking Protocol) about, 532 configuring, 55-61 configuring phones, 543-551 configuring VLANs, 29 DCHP for phones, 537 dangers of, 54-55 dial peers, 551-555 functionality, 49-52 dial plans, 542 network design considerations, 642 QoS on CME router, 536 trun