If a network administrator wants to view the routing between the Autonomous Systems, it would be a time-consuming task to get the values from each router. The accuracy is not guaranteed as well.
Using NetFlow Analyzer you can view the AS name and number using the BGP information exported from the router. This can be obtained using NetFlow Analyzer by implementing the following steps:
- Enabling BGP
- Exporting the Information in NetFlow packets
- Viewing the AS information
Enabling BGP
To enable the BGP in the router follow the steps mentioned below:
In the config mode of the router:
router bgp as-number <Enables the BGP routing process, which places the router in router configuration mode >
network network-number [mask network-mask] [route-map route-map-name] <Flags a network as local to this autonomous system and enters it to the BGP table >
To configure BGP neighbors:
neighbor {ip-address|peer-group-name} remote-as as-number <Specifies a BGP neighbor >
Sample configuration:
router bgp 109 network 131.108.0.0network 192.31.7.0neighbor 131.108.200.1 remote-as 167neighbor 131.108.234.2 remote-as 109neighbor 150.136.64.19 remote-as 99
Exporting the Information in NetFlow packets
Once you have enabled the BGP in the router you need to export the information in the NetFlow export.
Enable the command to export the bgp information:
ip flow-export {version}[peer-as | origin-as]
eg
ip flow-export version 9 origin-as
Viewing the AS information
To view the AS information navigate to Device tab in the NetFlow Analyzer, select Autonomous view ? Click on Start AS Collection. This will give you the information of the AS name and the number used with the IN and OUT Speed.
You can drill down to the AS number to view the graph based on Volume speed.
The AS information is displayed based on devices and not based on the interfaces and we will not be able to view the conversation for each AS. AS information collection is resource intensive, especially when configured for origin-AS.
Hope this helps.
Arun Karthik Asokan
NetFlow Analyzer Technical Team
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