Allied Telesis x908, X8100 manual Hierarchy of the Different Filters, BGP Example

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Hierarchy of the Different Filters

Hierarchy of the Different Filters

Hierarchy of the Different Filters

For distribute filters (ACLs), path filters, and prefix filters, the order of application is not important. If an update is denied by any given filter, it is discarded immediately, and is not run through any of the other filters. If an update is permitted by one filter, it is passed through to the next filter to be considered. At the end, you end up with the set of updates that all the filters agree should not be discarded.

However, route maps are applied last, after the other types of filter. This is because route maps can modify updates, not just accept or discard them.

BGP: Example

This How To Note illustrates each type of filter with an example from a very simple BGP network. This section describes the basic network configuration. The following sections add filtering options to it:

"Example: Distribute filters" on page 12

"Example: AS path filters" on page 18

"Example: Prefix filters" on page 23

The network consists of two BGP peers in different Autonomous Systems (AS):

port1.0.2, vlan 64:

64.64.64.64/4

Switch running

AlliedWare Plus

port1.0.1, vlan1:

 

45.45.45.45/24

ASN 34567

 

port 50, vlan 1:

45.45.45.46/8

Switch running

AlliedWare

port 52, vlan 2:

52.52.52.5/8

ASN 34568

Page 8 Use Route Maps and Other Filters to Filter and Alter BGP and OSPF Routes

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Contents Introduction Technical GuideContents IntroductionWhich products and software version does it apply to? BGP Applying Route Maps to Imported RoutesRelated How To Notes Which products and software version does it apply to?BGP peers BGP updatesBGP Concepts and Terminology Update attributes OriginAS-path Next-hopAccess Control List ACL filters BGP Overview of the Available Filter TypesFilter types Distribute filtersExamples for filtering BGP Update messages Difference and Relationship in BGPHierarchy of the Different Filters BGP Example Example Distribute filters on page  Example AS path filters on page  Example Prefix filters on pageBasic configuration awplus#show ip route Confirming the neighbor relationshipAlliedWare switch BGP Configuring Distribute Filters About ACLsFilter out one particular route from a neighbor Using ACLs as filtersExample Distribute filters Filter out a range of prefix lengths 6. Shut down the neighbor, and then bring it up again awplusconfig# neighbor 45.45.45.46 distribute-list list2 in3. Check that the IP route table now includes all the routes Use a numbered ACL instead of a named ACL awplusconfig-router# do show ip route BGP Configuring AS Path Filters AS path listsDiscard or allow routes from a neighbor Using AS path lists as path filtersExample AS path filters 7. Shut down the neighbor, and then bring it up again 4. Shut down the neighbor, and then bring it up againa neighbor Another example An outgoing filter that uses an AS-path listBGP Configuring AS Path Filters Mask length BGP Configuring Prefix FiltersAbout prefix lists Using prefix lists as prefix filters Example Prefix filtersawplusconfig-router# neighbor neighbor prefix-list list-name in awplusconfig-router# neighbor neighbor prefix-list list-name outFilter out a range of different prefix lengths BGP Configuring Prefix Filters BGP Configuring Route Maps Structure of a route mapAn AS path list Configuring a match clauseClauses A community list CaseOne or more prefixes, by using a prefix list One or more prefixes, by using an ACLConfiguring a set clause A next hop addressAn origin A metric the MED attributeset community community-values additive set weight set atomic-aggregateset extcommunity rtsoo ext-comm-number set ip next-hop ipaddThe effect of different combinations of clauses One match clause with an actionNo match clause and one or more set clauses A match clause and one or more set clausesUpdate from Peer Update 1 to PeerUpdate 2 to Peer Router ASFirst, enter BGP router mode for the AS. The prompt should look like Examples Example B Match on a prefix-list that denies an entryawplusconfig#ip prefix-list test1 permit 52.0.0.0/8 awplusconfig-route-map#set metric4. Apply this route map as the in route map on the neighbor Example D Matching on a next-hop prefix-list Example E Prepending AS numbersawplusconfig-route-map#match ip address awplusconfig-route-map#router bgp1. Configure the AW peer to send out a community number The routes coming from that peer has communityadd ip routem=com entry=1 set commmun=8989 set bgp peer=45.45.45.45 outroutemap=com sendcommunity=yesBGP#show ip route set bgp peer=45.45.45.45 outroutemap=mixed sendcommunity=yes 8. Add that ACL as a distribute-list in-filter on the neighbor route-map marker permit Examples ACLs Path filters Prefix filters Route mapsBGP Applying Route Maps to Imported Routes Syntaxneighbor default-originate Other Uses of Route Mapsneighbor unsuppress-map networkBGP Route Map Filtering Example BGP configurationRoute map configuration set local-preference route-map outdef permit Interface OSPF Configuring Route Maps for Filtering and Modifying OSPF RoutesMetric External route type A prefix, by using a prefix listA prefix, by using an ACL OSPF Applying Route Maps  Set the metric, by using the command set metric
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X8100, x908 specifications

The Allied Telesis x908 and the SwitchBlade x900 series of network switches are cutting-edge solutions designed to address the demands of modern networking environments. These switches are known for their high performance, reliability, and robust feature sets, making them ideal for enterprise and service provider networks.

The Allied Telesis x908 series consists of modular and chassis-based systems that can accommodate a variety of network configurations. One of the main features of the x908 series is its ability to offer high scalability with support for a large number of ports. This makes it suitable for data centers and large enterprise networks where space and bandwidth optimization are critical.

In addition to scalability, the x908 series supports advanced Layer 2 and Layer 3 switching capabilities. This allows for efficient traffic management and routing, ensuring that data is delivered swiftly and reliably. The x908 also incorporates intelligent features such as Quality of Service (QoS), which prioritizes critical network traffic, ensuring that time-sensitive data—like voice and video—maintains its quality during transmission.

The SwitchBlade x900 series takes this functionality further with its innovative modular architecture. This allows organizations to configure their networks to meet specific needs by choosing from a variety of interface cards and service modules. The SwitchBlade x900 also supports advanced security features such as Access Control Lists (ACLs) and VLAN segmentation, which provide enhanced protection against unauthorized access and network threats.

Another hallmark of the x908 and SwitchBlade series is their support for high-speed Ethernet technologies, including 10G and 40G Ethernet. This enables organizations to keep pace with the increasing bandwidth demands of applications and services, particularly in cloud computing and data-intensive workloads.

Both the x908 and the SwitchBlade x900 series are designed with energy efficiency in mind, featuring power-saving technologies that reduce overall operational costs. Coupled with Allied Telesis' management tools, which provide detailed analytics and monitoring, network administrators can optimize performance and energy consumption simultaneously.

In summary, the Allied Telesis x908 and SwitchBlade x900 series offer a comprehensive suite of features, high performance, scalability, and advanced networking technologies. They represent a strategic investment for organizations looking to build resilient, efficient, and future-proof network infrastructures.
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