defined, 11 subnetting, 673, 677-678 spanning tree design considerations, 104 ipv6 nd-suppress-ra command, 686 VLANs and, 28 ipv6 unicast-routing command, 685 leadership and mentoring, 730 IS-IS (Intermediate System-Intermediate LEAP (Lightweight Extensible Authentication System), 107, 126 Protocol), 514 ISDN (Integrated Services Digital Network), learning state, 91 LEC (local exchange carrier), 350 ISL (Inter-Switch Link) less command (NX-OS), 278 trunking support, 38, 39 lightweight access points (LAPs), 516 usage considerations, 40 Lightweight Extensible Authentication ITU (International Telecommunications Protocol (LEAP), 514 Union), 525 line authentication, 453 IXC (interexchange carrier), 347 line cards, 244 line coding, DS3, 379 line loopback, 367 line method, 454 J-carrier hierarchy, 347 line passwords, 437-439 Janitor Principle, 704 link aggregation jitter cross-stack EtherChannel, 75 defined, 531 EtherChannel, 63-75 VoIP issues, 531 Multichassis EtherChannel, 75 jitter buffers, 531 virtual Port-Channel, 75-80 join-failover-group command, 500 Link Aggregation Control Protocol (LACP), link state advertisements (LSAs), 138 Kerberos 5 authentication, 453, 456 link-local unicast addresses, 676 Keyboard Video Monitor (KVM), 645 link-state routing protocols, 124 krb5 method, 453, 456 listening state, 91 krb5-telnet method, 454 LLQ (low-latency queuing), 223, 582, 589- KVM (Keyboard Video Monitor), 645 LMI (Local Management Interface), 394-395, 404-407 load balancing, EtherChannel, 64-68 label stacks, 409 load command, 539 LACP (Link Aggregation Control Protocol), local access and transport area (LATA), 348 Local Area Networks (LANs), 2 LAG (see link aggregation) local exchange carrier (LEC), 350 LANs (Local Area Networks), 2 local loop, 350 LAPs (lightweight access points), 516 Local Management Interface (LMI), 394-395, last command (NX-OS), 278 404-407 last mile, 350 local method, 454, 456 LATA (local access and transport area), 348 local-case method, 454, 456 late collisions, 9 location servers, 555 latency 