Security
access-class <acl> in
On the VTY lines: only sources the ACL permits may open a telnet or SSH session. Others are refused before any login prompt.
Works on: Router, Firewall, Switch, Access pointMode: line
Example
R1(config)# access-list 10 permit 192.168.10.0 0.0.0.255
R1(config)# line vty 0 4
R1(config-line)# access-class 10 inRun this command live
Don't just read it — type access-class <acl> in in a real network simulator in your browser and watch it take effect. No install, no account needed to start.
Frequently asked
What does the "access-class <acl> in" command do?
On the VTY lines: only sources the ACL permits may open a telnet or SSH session. Others are refused before any login prompt.
Example of "access-class <acl> in"
R1(config)# access-list 10 permit 192.168.10.0 0.0.0.255 R1(config)# line vty 0 4 R1(config-line)# access-class 10 in
More Security commands
access-list <10-99> {permit|deny} <src> <wild>ip access-list extended <name><seq> {permit|deny} <protocol> <src> <dst> [echo-reply|established]show access-lists [name]ip access-group <acl> in|outswitchport port-securityswitchport port-security maximum <n>switchport port-security violation {shutdown|restrict|protect}switchport port-security mac-address {<H.H.H>|sticky}ip dhcp snoopingip arp inspection vlan <id>line vty 0 4