Re: Netflow export not working on ASR

CiscoBrownBelt · ‎05-06-2020

I know Cisco doc says "Management Interface--NetFlow data export is not supported through the Management Interface port."

What if the NetFlow collector is only reachable via the managment vrf or port? You must establish reachability via a different port other than the mgmt 0 port or a port that is assigned with the mgmt-vrf correct (it still accepts the "destination 11.1.1.20 vrf-mgmt" command)?

So i have NetFlow turned on another port, g0/1 like below, and source from that same port (no other up port or Lo available to source) but still does not show any data exported nor does the Collector show it receives anything when there is statistics (see below).

Also, if you enable the Monitor on a interface will entering a source command using the same interface not work?

This is my config:

flow record TEST-Record1
description Netflow to SW
match ipv4 source address
match ipv4 destination address
match ipv4 protocol
match transport source-port
match transport destination-port
match transport tcp destination-port
match transport udp destination-port
match ipv4 tos
match interface input
match interface output
collect timestamp sys-uptime first
collect timestamp sys-uptime last
collect timestamp absolute first
collect application name
collect counter bytes long
collect counter packets long
!
!
flow exporter TEST-Exporter1
destination 11.1.1.20 vrf-mgmt (tried without the vrf-mgmt too)

source gigabitEthernet 0/1
transport udp 2055
template data timeout 8400
option application-table timeout 60
option application-attributes timeout 300
!
!
flow monitor TEST-Monitor1
exporter Flow-Exporter1
cache timeout active 60
record Flow-Record1

interface gigabitEthernet 0/1

ip flow monitor TEST-Monitor1 input

------------------------

Flow Exporter TEST-Exporter1:
Packet send statistics (last cleared 00:06:14 ago):
Successfully sent: 1219 (1604180 bytes)
Reason not given: 4 (288 bytes)

Client send statistics:
Client: Option options application-name
Records added: 9856
- sent: 9856
Bytes added: 818048
- sent: 818048

Client: Option options application-attributes
Records added: 2766
- sent: 2766
Bytes added: 625116
- sent: 625116

Client: Flow Monitor TEST-Monitor1
Records added: 6
- sent: 6
Bytes added: 372
- sent: 372

Giuseppe Larosa · ‎05-07-2020

Hello @CiscoBrownBelt ,

you should apply the ip flow monitor to interfaces different from the one used to export flow statistics even if they are in a different VRF.

This should be a reasonable real world scenario.

Also interface gi0/1 must be a member of vrf vrf-mgmt to be able to reach the collector.

In the past many years ago I could see the flows of netflow exporting on the collector ( netflow version 5).

Hope to help

Giuseppe

CiscoBrownBelt · ‎05-07-2020

The interface the monitor is applied on is the interface I want to monitor. Would adding this to the vrf mgmt break traffic as this interface has sub-interface used for other routing (ROAS to switch type set-up)?
Only other interface is the mgm0 vrf port. Best option would be create a loopback and add that to the mgmt-vrf and source netflow from there correct?