IPv4: 32 bitsIPv6: 128 bits IPv6 address zero compression1234:1234:0000:0000:0000:0000:4567:4567 is 1234:1234::4567:4567IPv6 address leading compression1234:0000:0000:1234:0011:0022:0033:1234 is 1234::1234:11:22:33:1234IPv6 Uncompressing1234:123:AA::BBBB:CCC is 1234:0123:00AA:0000:0000:0000:BBBB:0CCC Global routing PrefixIANA(Internet Assigned Numbers Authority) - RIR(Rigional Internet Registrie..
Public IP address range:A: 1.0.0.0/8B: 128.0.0.0/16C: 192.0.0.0/24 Private IP address range:A: 10.0.0.0/8B: 172.16.0.0/12C: 192.168.0.0/16 Inside local address and outside local address. Local address is private address.Inside global address and outside global address. Global address is public address. Static NATR1(confin-int)#ip nat insideR1(confin-int)#ip nat insideR1(confin-int)#ip nat outsid..
To see system clock: show clockTo set system clock: clock set NTP stands for Network Time ProtocolStratum-0 device is top clock that is an atomic clock.Router will get time information from Stratum-1 device through NTP with port 123.NTP message will send through each devices,. For master, ntp master For client.ntp server 172.12.123.1 in master,R1#sho ntp ass address ref clock st when poll reach ..
ACL denies anything other than the list.Standard ACL only checks source IP addresswildcards: 0 for specific number, 1 for anything. Opposite to the subnet mask. wildcard mask eg. 0.0.0.255 Router(config)#access-list 1 deny 3.3.3.3 0.0.0.255 Router(config)#access-list 1 permit any Router#show ip accessStandard IP access list 1 10 deny 3.3.3.0 0.0.0.255 20 permit any Router(config-if)#ip access-gr..