ccna cloud 210-455 pdf

ccna cloud 210-455 pdf.permit icmp any any nd-na //IPv6ACL needs to implicitly allow sending and receiving of ND's NA (Neighbor Notice) packets on the interface permit icmp any any nd-ns //IPv6ACL needs to implicitly allow sending and receiving of ND's NS (Neighbor Request) packets on the interface deny ipv6 any any9.1.6 ACL Usage Principles ACLs are powerful and should be used in accordance with the following principles°1. Top-down processingACL table entries are checked in top-down order and start with the first table entry and finally reject all by default. Once a condition is matched, checking of subsequent table entries is stopped, so the order in which statements are configured in the ACL must be considered.2. Follow the principle of adding table entries at the endNew table entries are added to the end of an ACL by default without specifying a sequential number.3. ACL PlacementConsider placing Extended IPv4 ACLs and IPv6 ACLs as close to the source as possible to ensure that denied packets are filtered out as early as possible to avoid wasting network bandwidth. In addition, try to make the standard IPv4 ACL as close to the destination as possible. Since the standard IPv4 ACL only focuses on the source IPv4 address, making it close to the source will prevent packets from flowing to other ports.4. 3P PrincipleOnly one ACLo can be configured and applied for each direction (PerDirection) of each interface (PerInterface) for each protocol (PerProtocol).