Asymmetric routing: Occurs when traffic takes different paths in each direction between two points. This can lead to connectivity issues or data loss.
Packet counts: By comparing the number of inbound and outbound packets for a specific connection, you can identify inconsistencies. If one direction has significantly fewer packets than the other, it might indicate traffic being dropped or taking a different route.
While the other options might offer supporting information:
Timestamps (B): Can help identify delays or timeouts in specific directions, but won,t directly confirm different routing paths.
Port filtering (C): Can be helpful if asymmetric routing affects specific services (identified by ports), but doesn,t provide a definitive answer.
Error messages (D): Flow logs might not always have specific error messages related to asymmetric routing.