7 examples 7: bgp vpn typical samples of bgp vpn – Accton Technology ES4626 User Manual
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SwitchD (config-router-bgp)#neighbor 3.3.3.3 route-map set-metric out
SwitchD (config-router-bgp)#neighbor 1.1.1.1 remote-as 300
SwitchD (config-router-bgp)#exit
SwitchD (config)#route-map set-metric permit 10
SwitchD (Config-Router-RouteMap)#set metric 200
The configurations of SwitchB
SwitchB (config)#router bgp 400
SwitchB (config-router-bgp)#neighbor 4.4.4.4 remote-as 100
SwitchB (config-router-bgp)#neighbor 4.4.4.4 route-map set-metric out
SwitchB (config-router-bgp)#exit
SwitchB (config)#route-map set-metric permit 10
SwitchB (Config-Router-RouteMap)#set metric 50
SwitchA(config-router-bgp)# bgp always-compare-med
After the configuration above, SwitchB, SwitchC and SwitchD are assumed to send a
route 12.0.0.0 to SwitchA. According to the comparison of BGP route strategy; there is an
assumption that the routes sent by the three switches above have the same attribute
value before the comparison of metric attribute. At this time, the route with lower value is
the better route. But the comparison of metric attribute will only be done with the routes
from the same AS. For SwitchA, the routes passed SwitchC are preferable to the one
passed SwitchD. Because SwitchC and SwitchB are not located in the same AS, the
SwitchA will not do metric comparison between the two switches. If the metric
comparison between different AS is needed, the command” bgp always-compare-med”
will be used. If this command is configured, the routes passed SwitchB are the best to
SwitchA. At this time, the following command may be added on SwitchA: “SwitchA
(config-router-bgp)# bgp always-compare-med”
13.8.4.7 Examples 7: BGP VPN Typical samples of BGP VPN
Under the MPLS VPN environment, BGP act as the kernel route transmit tools and
the important tools to create ILM and FTN list on the edge equipments. On
ES4624-SFP/ES4626-SFP switch with LDP, it provides important support for the
application of MPLS VPN. Here, LDP works in the public network, BGP is not needed on
the non-edge routers of public network.