IOS: Access List (ACLs)

Configuring IP Access Lists: https://www.cisco.com/c/en/us/support/docs/security/ios-firewall/23602-confaccesslists.html#acltypes

Types of ACLs:

• Standard ACLs
• Extended ACLs
• Lock and Key (Dynamic ACLs)
• IP Named ACLs, Reflexive ACLs, Time-Based ACLs Using Time Ranges, Commented IP ACL Entries, Context-Based Access Control, Authentication Proxy, Turbo ACLs, Distributed Time-Based ACLs, Receive ACLs, Infrastructure Protection ACLs, Transit ACLs.

Process: Define ACL + Apply ACL to interface

• show access-list
• show ip access-list
• router(config)#access-list 101 deny icmp any any
• router(config)#access-list 101 permit ip any any

• router(config)#ip access-list extended test
• router(config-ext-nacl)#permit ip host 2.2.2.2 host 3.3.3.3
• router(config-ext-nacl)#permit tcp host 1.1.1.1 host 5.5.5.5 eq www
• router(config-ext-nacl)#permit icmp any any
• router(config-ext-nacl)#permit udp host 6.6.6.6 10.10.10.0 0.0.0.255 eq domain

To apply ACLs:

• ip access-group to apply an IPv4 access control list (ACL) to a Layer 3 interface

• copy running-config startup-config

Related terms

• VLAN Access-List (VACL)

See also

• Cisco IOS: Cisco IOS XE, Config (mode), VLANs, Cisco IOS logging, VTP, ACLs, show logging, show logging history, show interface status, debug, archive, show archive, conf t, int, ip http server, ip ssh, ip address, vty, show mac address-table, show access-list, Access-list, ip access-group, admin
• ACL, SubInACL.exe, Cisco ACLs, getfacl, setfacl, lsattr, chattr, xattr, NACLs