Standard Access List
Standard ACLs are used for everything from traffic filtering to route filtering and everything in between. Most people don’t use them for traffic filtering today, as they can only filter based on source address, extended ACLs are much more useful for traffic filtering. I use them for filtering debug output, access control to VTY lines, route update filtering, etc. Here is an example of a standard ACL being used for access control on the VTY lines of a IOS router.
SC#config terminal SC(config)#access-list 99 permit host 192.168.2.10 SC(config)#access-list 99 deny any any SC(config)#line vty 0 903 SC(config-line)#access-class 99 SC(config-line)#end SC(config)#