ccna complete guide book

ccna complete guide book.172.16.23.3, unsuccessful, check the IPv4 A of router R2R2#show ip access-lists Extended IP access list 120 10 permit tcp 172.16.1.0 0.0.0.255 host 172.16.12.2 eq telnet 20 permit tcp 172.16.1.0 0*0.0.255 host 172.16.23.2 eq telnet 30 permit udp any any eq 520 (10 matches) 40 Dynamic CCNA permit ip 172.16.1.0 0.0.0.255 host 172.16.233After the PCI±Telent router R2 succeeds, access the web service of router R3 on the PCI or ping172.16.23.3, which succeeds, look at the IPv4ACL of router R2--a R2#show ip access-lists Extended IP access list 120 10 permit tcp 172.16.1.0 0.0. 0.255 host 172.16.12.2 eq telnet (20 matches) 20 permit tcp 172.16.1.0 0.0.0.255 host 172.16.23.2 eq telnet 30 permit udp any any eq 520 (20 matches) 40 Dynamic CCNA permit ip 172.16.1.0 0.0.0.255 host 172.16.23.3 permit ip host 172.16.1.100 host172.16.23.3 (9 matches) (time left 565) Create a temporary entry dynamicallyFrom the output of and , we can see that the Telnet session from host 172.16.1.100 TelnetR2, if it passes the authentication, will be cut off immediately and the IOS software will dynamically create a temporary entry in the IPv4 ACL permit ip host 172.16.1.100 host 172.16.23.3o Since the autocommand command uses the following command Since the host parameter is used in the autocommand command, only authenticated host 172.16.1.100 is allowed to access the network in this dynamic entry, at which point the web service at host 172.16.1.100± accesses 172.16.23.3 or pings the address, successfully. The temporary entry will count down from a relative time of 10 minutes ( 600 seconds).9.2.5 Experiment 5: Configuring Self-reversing IPv4 ACLsChapter 9 ACLs .127 . Self-reversing IPv4 ACL I work principle.