IPv4 Access Control Lists (ACLs)

An Access Control List (ACL) is a list of one or more Access Control Entries (ACEs), where each ACE consists of a matching criteria and an action (permit or deny). The information below describes how to configure, apply, and edit static IPv4 ACLs in a network populated with switches, and how to monitor IPv4 ACL actions.

NOTE:
This chapter describes static ACLs for IPv4 configuration and operation. Because the switches covered by this guide support IPv4/IPv6 dual-stack operation, simultaneous operation of statically configured IPv4 and IPv6 ACLs is supported in these switches. However:

  • IPv6 ACLs are not supported on switches J9779A, J9780A, J9782A, and J9783A.

  • IPv4 and IPv6 ACEs cannot be combined in the same static ACL.

  • IPv4 and IPv6 static ACLs do not filter each other’s traffic.

In the following information, unless otherwise noted:

  • The term “ACL” refers to static IPv4 ACLs.

  • Descriptions of ACL operation apply only to static IPv4 ACLs.

See “IPv6 Access Control Lists (ACLs)” in the IPv6 Configuration Guide for your switch.

IPv4 filtering with ACLs can help improve network performance and restrict network use by creating policies for:

Switch Management Access: Permits or denies in-band management access, including limiting and/or preventing the use of designated protocols that run on top of IPv4, such as TCP, UDP, IGMP, ICMP, and others. Also included are the use of precedence and ToS criteria, and control for application transactions based on source and destination IPv4 addresses and transport layer port numbers.

Application Access Security: Eliminates unwanted traffic in a path by filtering IPv4 packets where they enter or leave the switch on specific VLAN interfaces.

IPv4 ACLs can filter traffic to or from a host, a group of hosts, or entire subnets.

NOTE:

IPv4 ACLs can enhance network security by blocking selected traffic, and can serve as part of your network security program. However, because ACLs do not provide user or device authentication, or protection from malicious manipulation of data carried in IPv4 packet transmissions, they should not be relied upon for a complete security solution.

IPv4 ACLs on the switches covered by this manual do not filter non-IPv4 traffic such as IPv6, AppleTalk, and IPX packets.