s private IP space, 649-652 International Telecommunications Union ip classless command, 724 (ITU), 525 ip default-gateway command, 519 Internet Assigned Numbers Authority (IANA), ip dhcp pool command, 517 120, 649 ip load-sharing per-destination command, 219 Internet Control Message Protocol (ICMP), IP networks allocating space, 656-658 Internet Engineering Task Force (IETF), 672, allocating subnets, 658-669 CIDR support, 654-656 Internet layer (ecommerce website), 643 documenting, 633 Internet Stream Protocol, 672 public versus private IP space, 649-652 Internetwork Operating System (see IOS) subnet principles, 663-669 interrupt context switching VLSM support, 652 CEF, 213-216, 219 ip ospf priority command, 140 defined, 207, 210 ip policy command, 203 disabling paths, 216 IP precedence, 578-581 fast switching, 211-213, 218 ip reflexive-list timeout command, 435 optimum switching, 213 ip route-cache cef command, 219 steps for, 210-211 ip route-cache command, 218 types supported, 207 IP routing table interswitch trunks, 630 about, 109-111 Intrusion Detection System Modules (IDSMs), default route, 114 15, 248 host route, 111 Intrusion Detection Systems (IDSs), 332 major network, 113 inverse ARP, 389, 399 subnets, 112 inverse masks, 416 summary route, 112, 655 IOS (Internetwork Operating System) supernet, 114 about, 10 ip standby command, 181 CatOS switch comparison, 249-253 ip subnet-zero command, 724 configuring EtherChannel, 70-73 IPv4 addresses configuring SVIs, 223-225 about, 673 configuring trunks, 42 depletion of, 671 configuring VLANs, 31-34 interoperability with IPv6, 674 login authentication, 453-455 ipv6 address autoconfig command, 682 MAC address table, 11 ipv6 address eui-64 command, 681 managing spanning tree, 91 IPv6 addresses NAT Overload, 501 about, 673-674 NTP client, 693-695 address types, 675-677 NTP server, 696 background information, 672 NX-OS comparison, 274-279 interoperability with IPv4, 674 VTP domains, 55 NAT and, 678 Index router configuration, 679-688 Layer-3 switches subnet masks, 675 