Autonomous system requirements for NTA
If you want to monitor autonomous systems via BGP, the flows have to contain information in appropriate bytes or fields.
NTA does not support extracting BGP information from sFlows.
NetFlow v5 and compatible flows
The flow record has to contain data for the following bytes:
| Bytes | Contents | Description |
|---|---|---|
| 40-41 | src_as | Autonomous system number |
| 42-43 | dst_as | Autonomous system number |
For more information, search for NetFlow export datagram format on www.cisco.com.
NetFlow v9, IPFIX, and compatible flows
The flow record from autonomous systems has to contain data in the following field types.
| Field Type | Value | Length (bytes) | Description |
|---|---|---|---|
| SRC_AS | 16 | N (default 2) | Source BGP autonomous system number where N could be 2 or 4. |
| DST_AS | 17 | N (default 2) | Destination BGP autonomous system number where N could be 2 or 4. |
| PeerSrcAS | 129 | N (default 2) | Peer source autonomous system number |
| PeerDstAS | 128 | N (default 2) | Peer destination autonomous system number |
For more information, search for NetFlow version 9 flow record format on www.cisco.com.