Ungyi Tech

RSTP: Rapid Spanning Tree Protocol (802.1w) Compare to 30 second delay in STP, RSTP is faster. It require root bridge. Second switch to root goes to alternate mode and act as backup. Point-to-Point (PTP) port needs to be full-duplex. edge-port is the end-client, switch forware packets to non-edge ports. RSTP switch generates BPDU every 2 seconds. It ages when there is no 3 BPDU message (6 second..

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..

Scenario: R1 need to communicate to loopback (2.2.2.2) in R2. FastEthernet connection through switch is stable and fast. But we also have another connection using Serial connection through ISP. Ideally, serial connection should work only the fastethernet connection is unavailable.When R1 set both ripv2 with FastEthernet and static with serial at the same time, router check the mask length (which..

R1# ping4.4.4.4 show ip route 4.0.0.0router ripmaximum-path 8 #change maximum path to 8. set as 1 is disabling traceroute 4.4.4.4 debug ip ripStop command working - Crtl + Shift + 6 (same as Ctrl+c in cmd)

router rippassive-int fast 0/1 #Disable update rip routing from f0/1show ip protocolsCtrl + a # move Cursor to frontpassive-int default #make every port passiveno passive-int serial 0/1/0 #disable passive only for serial 0/1/0 Administrative distancesLonger subnet mask is used. in this case, EIGRP is used.Default ad is 120. Lower AD has higher priority.AD table demands on Routing protocol.