Access List
- Provide basic security mechanisms.
- Control propagation of service advertisements.
- Help select specific packets for encryption.
- A. Access lists are applied on a per interface basis.
- Lower bandwidth requirements at the expense of greater CPU utilization.
- The end of an access list can be said to contain an implicit 'deny' for all traffic.
- The order of an access control list is important.
- Defines the type of traffic that will be considered interesting
in Cisco terminology. The list contains a series of statements, each of which
uses the keyword permit or deny. By configuring a list of these
statements the network engineer can selectively define which traffic will allow
the router to dial out.
- Access Lists are pretty versatile. In addition to providing basic filtering for security, they can provide IPX SAP filtering and help select packets for encryption. They cannot, however, evaluate packets in reference to those that came before. They evaluate a packet and forget it.
Queueing Methods
- Custom Queuing
- Uses a series of configurable queues that are processed in round-robin order.
- Provides some level of service to all traffic.
- Enables the assignment of queue space to various types of traffic and then services them in round-robin fashion. This way, all types of traffic can be serviced.
- Priority Queuing uses four queues, and processes traffic
based on its assigned importance (high, medium, normal, or low).
-
Weighted Fair Queuing is enabled by default, and is suited for low-volume,
interactive traffic.
- To help prevent certain applications from monopolizing bandwidth, it queues packets based on the arrive time of the last (rather than the first) bit.
- First implemented in IOS 11.0, WFQ is on by default. One example of its benefit is the way it keeps an application like FTP from dominating the bandwidth.
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