Restrictions for VXLAN-Aware Flexible NetFlow
Traffic capture using VXLAN-aware Flexible NetFlow is limited to unicast traffic.
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Traffic capture using VXLAN-aware Flexible NetFlow is limited to unicast traffic.
Flexible NetFlow (FNF) uses flows to provide statistics for accounting, network monitoring, and network planning. VXLAN-aware FNF provides information about the VXLAN-encapsulated IPV4 and IPV6 packets in the network. VXLAN-aware FNF captures the VXLAN flow information for both bridged and routed traffic.
A flow is a unidirectional stream of packets that arrives on a source interface and has the same values for the keys. A key is an identified value for a field within the packet. You create a flow using a flow record to define the unique keys for your flow. FNF allows you to define an optimal flow record for a particular application by selecting the keys from a large collection of predefined fields. All key values must match for the packet to count in a given flow. Flows are stored in the FNF cache. You can export the data FNF gathers for your flow by using an exporter.
In a BGP EVPN VXLAN fabric, an FNF monitor is configured on the NVE interface on a VTEP and on the physical interface on a spine switch. For more information about FNF, see Configuring Flexible NetFlow module of the Network Management Configuration Guide.
To configure VXLAN-aware FNF, perform these steps:
Create a flow record by specifying key fields and non-key fields to the flow.
Create a flow exporter by specifying the export protocol and transport destination port, source, and other parameters.
Create a flow monitor based on the flow record and flow exporter.
Apply the flow monitor to the network virtualization edge (NVE) interface on the VTEPs.
Note |
The commands listed in this section are applicable only to VXLAN-aware FNF. For detailed steps to configure FNF, see How to Configure Flexible Netflow section in the Configuring Flexible NetFlow module of the Network Management Configuration Guide. |
To configure a flow record for VXLAN-aware FNF, perform the following steps:
Note |
All the match commands listed in this configuration task are mandatory. |
Command or Action | Purpose | |||
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Step 1 |
enable Example:
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Enables privileged EXEC mode. Enter your password, if prompted. |
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Step 2 |
configure terminal Example:
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Enters global configuration mode. |
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Step 3 |
flow record flow-record-name Example:
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Creates a flow record and enters flow record configuration mode. This command also allows you to modify an existing flow record.
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Step 4 |
match datalink vlan { input | output} Example:
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Configures the VLAN ID (for input or output traffic) as a key field for the FNF flow record.
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Step 5 |
match routing vrf input Example:
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Configures the VRF ID (for input or output traffic) as a key field for the FNF flow record.
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Step 6 |
match vxlan vtep { input | output} Example:
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Configures the VTEP ID as a key field for the FNF flow record. The input keyword shows the VTEP source IP address in the captured flow. The output keyword shows the VTEP destination IP address in the captured flow |
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Step 7 |
match vxlan vnid Example:
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Configures the VXLAN VNI ID as a key field for the FNF flow record. |
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Step 8 |
end Example:
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Returns to privileged EXEC mode. |
To configure flow exporter for VXLAN-aware FNF, perform the following steps:
Command or Action | Purpose | |||||
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Step 1 |
enable Example:
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Enables privileged EXEC mode. Enter your password, if prompted. |
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Step 2 |
configure terminal Example:
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Enters global configuration mode. |
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Step 3 |
flow exporter flow-exporter-name Example:
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Creates a flow exporter and enters flow exporter configuration mode. |
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Step 4 |
destination ipv4-address Example:
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Sets the IPv4 destination address or hostname for the exporter. |
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Step 5 |
source interface-type interface-number Example:
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Specifies the interface to use to reach the NetFlow collector at the configured destination. Ensure that the source IP address is unique per fabric.
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Step 6 |
ttl seconds Example:
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Configures the time-to-live (TTL) value for datagrams sent by the exporter. The range is from 1 to 255 seconds. The default is 255. |
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Step 7 |
transport udp port-number Example:
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Specifies the UDP port to use to reach the NetFlow collector. |
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Step 8 |
export-protocol { ipfix | netflow-v9} Example:
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Specifies the version of the NetFlow export protocol used by the exporter. |
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Step 9 |
end Example:
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Returns to privileged EXEC mode. |
To configure a flow monitor for VXLAN-aware FNF, perform the following steps:
Command or Action | Purpose | |
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Step 1 |
enable Example:
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Enables privileged EXEC mode. Enter your password, if prompted. |
Step 2 |
configure terminal Example:
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Enters global configuration mode. |
Step 3 |
flow monitor flow-monitor-name Example:
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Creates a flow monitor and enters flow monitor configuration mode. This command also allows you to modify an existing flow monitor. |
Step 4 |
exporter flow-exporter-name Example:
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Specifies the name of the flow exporter that was created previously and associates it with the specified flow monitor. |
Step 5 |
record flow-record-name Example:
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Specifies the record for the flow monitor. |
Step 6 |
end Example:
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Returns to privileged EXEC mode. |
To configure VXLAN-aware FNF on the NVE interface of a VTEP, perform the following steps:
Command or Action | Purpose | |
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Step 1 |
enable Example:
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Enables privileged EXEC mode. Enter your password, if prompted. |
Step 2 |
configure terminal Example:
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Enters global configuration mode. |
Step 3 |
interface nve-interface-number Example:
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Specifies the network virtualization edge (NVE) interface number and enters interface configuration mode. |
Step 4 |
ip flow monitor flow-monitor-name { input | output} Example:
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Associates the IPv4 flow monitor to the NVE interface for input or output packets. |
Step 5 |
ipv6 flow monitor flow-monitor-name { input | output} Example:
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Associates the IPv6 flow monitor to the NVE interface for input or output packets. |
Step 6 |
end Example:
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Returns to privileged EXEC mode. |
This section provides configuration examples for VXLAN-aware FNF using the following topology:
The following table provides a sample configuration for VTEP 1 to enable VXLAN-aware FNF:
VTEP 1 |
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The following example provides a sample output to check the IPv4 input flow monitor cache output on VTEP 1:
Leaf-01# configure terminal
Leaf-01(config)# show flow monitor vxlan_nf_monitor_input cache format table
Cache type: Normal (Platform cache)
Cache size: 10000
Current entries: 4
Flows added: 8
Flows aged: 4
- Inactive timeout ( 100 secs) 4
DATALINK VLAN INPUT DATALINK MAC SRC ADDR INPUT DATALINK MAC DST ADDR INPUT IP VRF ID INPUT IPV4 SRC ADDR IPV4 DST ADDR TRNS SRC PORT TRNS DST PORT ICMP IPV4 TYPE ICMP IPV4 CODE IGMP TYPE INTF INPUT FLOW DIRN VXLAN VXLAN VNID VXLAN VXLAN VTEP INPUT VXLAN VXLAN VTEP OUTPUT IP PROT IP TTL bytes long pkts long time abs first time abs last
=================== =========================== =========================== ============================= =============== =============== ============= ============= ============== ============== ========= ==================== ========= ==================== ====================== ======================= ======= ====== ==================== ==================== ============== =============
13 AAAA.CCCC.1003 AAAA.BBBB.1003 3 (l3vni5001) 192.168.13.3 192.168.13.2 0 0 0 0 0 Null Input 10013 2.2.2.2 1.1.1.1 61 64 43517376 43172 14:00:41.391 14:01:34.391
11 AAAA.CCCC.1001 AAAA.BBBB.1001 2 (l3vni5000) 192.168.11.3 192.168.11.2 0 0 0 0 0 Null Input 10011 2.2.2.2 1.1.1.1 61 64 43517376 43172 14:00:41.391 14:01:34.391
10 AAAA.CCCC.1002 AAAA.BBBB.1002 2 (l3vni5000) 192.168.10.3 192.168.10.2 0 0 0 0 0 Null Input 10010 2.2.2.2 1.1.1.1 61 64 43517376 43172 14:00:41.391 14:01:34.391
12 AAAA.CCCC.1004 AAAA.BBBB.1004 3 (l3vni5001) 192.168.12.3 192.168.12.2 0 0 0 0 0 Null Input 10012 2.2.2.2 1.1.1.1 61 64 43517376 43172 14:00:41.391 14:01:34.391
Leaf-01#
The following example provides a sample output to check the IPv4 output flow monitor cache output on VTEP 1:
Leaf-01# configure terminal
Leaf-01(config)# show flow monitor vxlan_nf_monitor_output cache format table
Cache type: Normal (Platform cache)
Cache size: 10000
Current entries: 4
Flows added: 8
Flows aged: 4
- Inactive timeout ( 100 secs) 4
DATALINK MAC DST ADDR OUTPUT IPV4 SRC ADDR IPV4 DST ADDR TRNS SRC PORT TRNS DST PORT DATALINK VLAN OUTPUT VXLAN VXLAN VNID VXLAN VXLAN VTEP INPUT VXLAN VXLAN VTEP OUTPUT IP PROT bytes long pkts long time abs first time abs last
============================ =============== =============== ============= ============= ==================== ==================== ====================== ======================= ======= ==================== ==================== ============== =============
AAAA.CCCC.1002 192.168.10.2 192.168.10.3 0 0 10 10010 1.1.1.1 2.2.2.2 61 44812536 43172 14:00:41.391 14:01:34.391
AAAA.CCCC.1004 192.168.12.2 192.168.12.3 0 0 12 10012 1.1.1.1 2.2.2.2 61 44812536 43172 14:00:41.391 14:01:34.391
AAAA.CCCC.1003 192.168.13.2 192.168.13.3 0 0 13 10013 1.1.1.1 2.2.2.2 61 44812536 43172 14:00:41.391 14:01:34.391
AAAA.CCCC.1001 192.168.11.2 192.168.11.3 0 0 11 10011 1.1.1.1 2.2.2.2 61 44812536 43172 14:00:41.391 14:01:34.391
Leaf-01#
The following example provides a sample output to check the IPv6 input flow monitor cache output on VTEP 1:
Leaf-01# configure terminal
Leaf-01(config)# show flow monitor vxlan_nf_v6monitor_input cache format table
Cache type: Normal (Platform cache)
Cache size: 10000
Current entries: 4
Flows added: 8
Flows aged: 4
- Inactive timeout ( 100 secs) 4
IPV6 SRC ADDR IPV6 DST ADDR TRNS SRC PORT TRNS DST PORT VXLAN VXLAN VNID VXLAN VXLAN VTEP INPUT VXLAN VXLAN VTEP OUTPUT IP PROT bytes long pkts long time abs first time abs last
============================================= ============================================= ============= ============= ==================== ====================== ======================= ======= ==================== ==================== ============== =============
192:168:12::3 192:168:12::2 0 0 10012 2.2.2.2 1.1.1.1 59 43517376 43172 14:00:41.391 14:01:34.391
192:168:10::3 192:168:10::2 0 0 10010 2.2.2.2 1.1.1.1 59 43517376 43172 14:00:41.391 14:01:34.391
192:168:13::3 192:168:13::2 0 0 10013 2.2.2.2 1.1.1.1 59 43517376 43172 14:00:41.391 14:01:34.391
192:168:11::3 192:168:11::2 0 0 10011 2.2.2.2 1.1.1.1 59 43517376 43172 14:00:41.391 14:01:34.391
Leaf-01#