Lenovo Flex System Fabric CN4093 User Manual

462 CN4093 Application Guide for N/OS 8.4
BGP Failover Configuration
UsethefollowingexampletocreateredundantdefaultgatewaysforaCN4093ata
WebHost/ISPsite,eliminatingthepossibility,shouldonegatewaygodown,that
requestswillbeforwardedtoanupstreamrouterunknowntotheswitch.
AsshowninFigure 45,theswitchisconnectedtoISP1andISP
2.Thecustomer
negotiateswithbothISPstoallowtheswitchtousetheirpeerroutersasdefault
gateways.TheISPpeerrouterswillthenneedtoannouncethemselvesasdefault
gatewaystotheCN4093.
Figure 45. BGPFailoverConfigurationExample
OntheCN4093,onepeerrouter(thesecondaryone)isconfiguredwith
alongerAS
paththantheother,sothatthepeerwiththeshorterASpathwillbeseenbythe
switchastheprimarydefaultgateway.ISP2,thesecondarypeer,isconfigured
withametricof“3,”therebyappearingtotheswitchtobethreerouterhopsaway.
1.
DefinetheVLANs.
Forsimplicity,bothdefaultgatewaysareconfiguredinthesameVLANinthis
example.ThegatewayscouldbeinthesameVLANordifferentVLANs
.
2. DefinetheIPinterfaceswithIPv4addresses.
TheswitchwillneedanIPinterfaceforeachdefaultgatewaytowhichitwillbe
connected.EachinterfacemustbeplacedintheappropriateVLAN.These
interfaceswillbeusedastheprimaryandsecondarydefaultgatewaysforthe
switch.
ISP 1
AS 100
BladeCenter
Server 1
IP: 200.200.200.10
Server 2
IP: 200.200.200.11
IP: 200.200.200.1
IP: 210.210.210.1
ISP 2
AS 200
Peer 1 Router
(Primary)
IP:200.200.200.2
Default gateway,
with routes having
shorter AS PATH
GbE Switch Module
announces routes with
metric of “3”
Peer 2 Router
(Secondary)
IP:210.210.210.2
Metric = AS path
length (metric of ‘3’) = local
AS repeated 3 times
CN 4093(config)# vlan 1
CN 4093(config)# interface ip 1 address 200.200.200.1 255.255.255.0 enable
CN 4093(config-ip-if)# exit
CN 4093(config)# interface ip 2 address 210.210.210.1 255.255.255.0 enable
CN 4093(config-ip-if)# exit

Lenovo Flex System Fabric CN4093 Specifications

General

Brand	Lenovo
Model	Flex System Fabric CN4093
Category	Switch
Language	English