Access Lists

What Are Access Lists?
–Standard
- Checks source address
- Generally permits or denies entire protocol suite
–Extended
- Checks source and destination address
- Generally permits or denies specific protocols
• Inbound or outbound
Why Use Access Lists?
– Manage IP traffic as network access grows.
– Filter packets as they pass through the router
Access List Applications
– Permit or deny packets moving through the router.
– Permit or deny vty access to or from the router.
– Without access lists, all packets could be transmitted onto all parts of your network.
Other Access List Uses

- Special handling for traffic based on packet tests
Outbound Access Lists
• If no access list statement matches, then discard the packet.