You have configured a standard access control list on a router and applied it to interface Serial 0
in an outbound direction. No ACL is applied to Interface Serial 1 on the same router. What
happens when traffic being filtered by the access list does not match the configured ACL
statements for Serial 0?
A.
The resulting action is determined by the destination IP address.
B.
The resulting action is determined by the destination IP address and port number.
C.
The source IP address is checked, and, if a match is not found, traffic is routed out interface
Serial 1.
D.
The traffic is dropped.
Explanation:
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a008010
0548.shtml
Introduction
This document provides sample configurations for commonly used IP Access Control Lists (ACLs),
which filter
IP packets based on:
Source address
Destination address
Type of packet
Any combination of these items
In order to filter network traffic, ACLs control whether routed packets are forwarded or blocked at
the router interface. Your router examines each packet to determine whether to forward or drop
the packet based on the criteria that you specify within the ACL. ACL criteria include:
Source address of the traffic
Destination address of the traffic
Upper-layer protocol
Complete these steps to construct an ACL as the examples in this document show:
Create an ACL.
Apply the ACL to an interface.
The IP ACL is a sequential collection of permit and deny conditions that applies to an IP packet.
The router tests packets against the conditions in the ACL one at a time.
The first match determines whether the Cisco IOS® Software accepts or rejects the packet.
Because the Cisco IOS Software stops testing conditions after the first match, the order of the
conditions is critical. If no conditions match, the router rejects the packet because of an implicit
deny all clause.