02-01-2018 02:49 AM - edited 03-01-2019 08:43 AM
Hello!
I have setup L2 NetFlow on a Nexus 5696Q running 7.3(2)N1(1) code as follows:
feature netflow ! flow exporter mac-netflow-export destination 172.28.0.254 use-vrf management transport udp 2055 version 9 !
sampler mac-netflow-sampler mode 1 out-of 1024 ! flow monitor mac-netflow-monitor record netflow layer2-switched input exporter mac-netflow-export !
I am applying the monitor ingress to a port-channel as follows:
interface port-channel16 switchport mode trunk switchport trunk allowed vlan 2101-2106,2196,2209-2212,3241 spanning-tree port type edge trunk speed 10000 vpc 16 layer2-switched flow monitor mac-netflow-monitor input sampler mac-netflow-sampler
.
Port-channel 16 spans two 5696Q switches (using vPC 16) and the configuration above is applied ONLY on one of them for testing purposes.
The problem is that no flows are exported even though it looks that flows are created:
hostname# sh flow exporter Flow exporter mac-netflow-export: Destination: 172.28.0.254 VRF: management (1) Destination UDP Port 2055 Export Version 9 Exporter Statistics Number of Flow Records Exported 0 Number of Templates Exported 0 Number of Export Packets Sent 0 Number of Export Bytes Sent 0 Number of Destination Unreachable Events 0 Number of No Buffer Events 0 Number of Packets Dropped (No Route to Host) 0 Number of Packets Dropped (other) 0 Number of Packets Dropped (LC to RP Error) 0 Number of Packets Dropped (Output Drops) 358 Time statistics were last cleared: Never
.
hostname# sh flow details Total number of flows = 33 Maximum flow count = 524288 (constant) IPV4 flow failure count = 0 IPV6 flow failure count = 0 mpls flow failure count = 0 l2 flow failure count = 0 input flow failure count = 0 output flow failure count = 0 glbl_flow_cnt_create_total = 7957 glbl_flow_cnt_delete_total = 7924
.
hostname# sh flow record netflow layer2-switched input Flow record netflow layer2-switched input: Description: layer2-switched input NetFlow No. of users: 1 Template ID: 259 Fields: match interface input match interface output match datalink mac source-address match datalink mac destination-address match datalink source-vlan-id match datalink ethertype match flow direction collect counter bytes collect counter packets collect timestamp sys-uptime first collect timestamp sys-uptime last
Any thoughts as to why this is the case?
Thanks in advance.
Regards,
Kostas
Solved! Go to Solution.
02-01-2018 08:45 AM
To answer my own question, it seems that the source interface under the exporter configuration is required.
flow exporter mac-netflow-export destination 172.28.0.254 use-vrf management transport udp 2055 source mgmt0 !--- Missing command from original configuration version 9
Once this was done, flows started exporting (and dropped where zeroed):
hostname# sh flow exporter Flow exporter mac-netflow-export: Destination: 172.28.0.254 VRF: management (1) Destination UDP Port 2055 Source Interface mgmt0 (172.17.1.25) Export Version 9 Exporter Statistics Number of Flow Records Exported 433 Number of Templates Exported 3 Number of Export Packets Sent 165 Number of Export Bytes Sent 22072 Number of Destination Unreachable Events 0 Number of No Buffer Events 0 Number of Packets Dropped (No Route to Host) 0 Number of Packets Dropped (other) 0 Number of Packets Dropped (LC to RP Error) 0 Number of Packets Dropped (Output Drops) 0 Time statistics were last cleared: Thu Feb 1 18:03:25 2018
02-01-2018 08:45 AM
To answer my own question, it seems that the source interface under the exporter configuration is required.
flow exporter mac-netflow-export destination 172.28.0.254 use-vrf management transport udp 2055 source mgmt0 !--- Missing command from original configuration version 9
Once this was done, flows started exporting (and dropped where zeroed):
hostname# sh flow exporter Flow exporter mac-netflow-export: Destination: 172.28.0.254 VRF: management (1) Destination UDP Port 2055 Source Interface mgmt0 (172.17.1.25) Export Version 9 Exporter Statistics Number of Flow Records Exported 433 Number of Templates Exported 3 Number of Export Packets Sent 165 Number of Export Bytes Sent 22072 Number of Destination Unreachable Events 0 Number of No Buffer Events 0 Number of Packets Dropped (No Route to Host) 0 Number of Packets Dropped (other) 0 Number of Packets Dropped (LC to RP Error) 0 Number of Packets Dropped (Output Drops) 0 Time statistics were last cleared: Thu Feb 1 18:03:25 2018
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