SNR S2989G-48TX-RPS — routing Protocols and Access Control Configuration Guide [229/553]

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S2989G-24TX Operation Manual

Chapter 4 Routing Protocol Related Configuration

4-4

sequence-number. Match clauses define matching rules. The matching objects are some

properties of routing messages. Different match clause in the same node is “and” relation

logically, which means the matching test of a node, will not be passed until conditions in its

entire match clause are matched. Set clause specifies actions, namely configure some

properties of routing messages after the matching test is passed.

Different nodes in a route-map is an “or” relation logically. The system checks each

node of the route-map in turn and once certain node test is passed the route-map test will

be passed without taking the next node test.

2. access control list(acl)

ACL (Access Control Lists) is a data packet filter mechanism in the switch. The switch

controls the network access and secure the network service by permitting or denying

certain data packet transmtting out from or into the network. Users can establish a group

of rules by certain messages in the packet, in which each rule to be applied on certain

amount of matching messages: permit or deny. The users can apply these rules to the

entrance or exit of specified switch, with which data stream in certain direction on certain

port would have to follow the specified ACL rules in-and-out the switch. Please refer to

chapter “ACL Configuration”.

3. Ip-prefix list

The ip-prefix list acts similarly to acl while more flexible and more understandable.

The match object of ip-prefix is the destination address messages field of routing

messages when applied in routing messages filtering.

An ip-prefix is identified by prefix list name. Each prefix list may contain multiple items,

each of which specifies a matching range of a network prefix type and identifies with a

sequence-number which specifies the matching check order of ip-prefix.

In the process of matching, the switch check each items identified by sequence-

number in ascending order and the filter will be passed once certain items is matched(

without checking rest items)

4. Autonomic system path information access-list as-path

The autonomic system path information access-list as-path is only used in BGP. In

the BGP routing messages packet there is an autonomic system path field (in which

autonomic system path the routing messages passes through is recorded). As-path is

specially for specifying matching conditions for autonomic system path field.

As for relevant as-path configurations, please refer to the ip as-path command in

BGP configuration.

5. community-list

Community-list is only for BGP. There is a community property field in the BGP

routing messages packet for identifying a community. The community list is for specifying

matching conditions for Community-list field.