Enterasys ssr-atm29-02 ユーザーガイド

ページ / 386
CoreWatch User’s Guide
363
Glossary
Access Control List (ACL)
List the SSR keeps to restrict Layer 3/4 traffic going through the router. Each ACL or each 
list consists of one or more rules describing a particular type of IP or IPX traffic. An ACL 
can be simple and consist of only one rule or complicated with many rules. Each rule tells 
the router to either permit or deny the packet that matches the rule’s packet description. 
For more information on ACLs and rules, refer to the SmartSwitch Router User Reference 
Manual
.
Adjacency
An OSPF relationship formed between selected neighboring routers for the purpose of 
exchanging routing information. Not every pair of neighboring routers become adjacent.
Aggregation
The combining of the characteristics of several different routes in such a way that a single 
route can be advertised. Aggregation reduces the amount of information that the routers 
must store and exchange.
Area
A set of networks grouped together but located in the same autonomous system. Setting 
up areas reduces OSPF routing traffic because each area's topology is invisible to the rest 
of the autonomous system.
AS Path
Attribute composed of a sequence of autonomous system path segments. The paths can be 
defined in ordered or unordered sets. The sets include the autonomous systems a route 
has traversed. The sets are used in aggregation and reduce routing information by listing 
each system only once regardless of how many times those systems are included in 
different paths.
Authentication Key
Parameter that guarantees that routing information is only imported from trusted routers. 
Many protocols, such as RIP version 2 and OSPF, provide mechanisms for authenticating 
protocol exchanges. An authentication key permits generation and verification of the 
authentication field in protocol packets.