2 Replies Latest reply on Nov 26, 2019 5:19 AM by picuet

    Traffic per VLAN (Cisco)


      We have a infrastructure made up of entirely Cisco devices, with the Core being 3850's, access layer of 3650's, and data center switches a mix of 5k and 9k's.


      This is a large research company with 92 VLAN's breaking up the various lab networks. Roughly half of the VLAN's are routed across the core, with the other half being routed across the FMC.


      I need to track the amount of traffic over the VLAN's but I havent been able to figure out how to make that happen. I have NetFlow configured on all our network devices, except the FMC (thats going to be a nightmare) and can see the data in NTA, so that part is working.


      When I try to configure a Monitor on a VLAN interface on the Core (3850) I get the following error:


      % Flow Monitor: Flow Monitor 'Netflow-Monitor-In' flexible netflow not supported on vlan interfaces


      Anyone know how to set the 3850's up so I can get NTA to report VLAN traffic?


      Per Cisco documentation, https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/37e/flexible_netflow/configuration_guid… , page 3, "Layer2, VLAN,WLAN and Layer3 interfaces are supported,but the switch does not support SVI and tunnels."




      I ended up applying the Flow Record to the Layer 2 Vlans [vlan config ###]. I can see the data on NTA, but its still not represented in a data per VLAN point of view. I need to be able to see how much data is flowing over a VLAN, and VLAN to VLAN traffic.