Netflow is the very basic need which is required when troubleshooting Network slowness problems. Unfortunately Cisco 4500 switch does not have General/Traditional Netflow which we configure on Cisco Routers and Cisco 6500 switches etc. Cisco 4500 only supports Flexible Netflow which is basically Netflow V9. In this post I will guide you to configure Flexible Netflow in Cisco 4500 switch.
There are 4 steps to configure Flexible Netflow in Cisco 4500 switch:
- Create a flow record
- Create a flow exporter
- Create a flow monitor
- Apply the monitor to an interface
Step 1 : Create Flow record :
The flow record defines the fields that will be used to group traffic into unique flows. In my example, I used the following configuration:
flow record IPV4-FLOW-RECORD match ipv4 tos match ipv4 protocol match ipv4 source address match ipv4 destination address match transport source-port match transport destination-port collect interface input collect interface output collect counter bytes long collect counter packets long
Step 2 : Create Flow Export :
In flow exporter we configure the IP of netflow analyser tool which will receive Netflow data. By default, Cisco will send data to UDP Port 9995 but you can configure this port to any number. I have also configured Source Interface which is reachable from Netflow analyser server.
flow exporter Netflow_analyser destination 192.168.0.245 source Loopback0 transport udp 9995
Step 3 : Create Flow Monitor :
The flow monitor is where you link records and exporters together :
flow monitor IPV4-FLOW description Used for Monitoring IPv4 Traffic record IPV4-FLOW-RECORD exporter Netflow_analyser
Now its time to apply this to Interface where we want to enable Netflow.
Step 4 : Apply The Configuration :
First we will apply it to SVI vlan port :
4500(config)#vlan config 2 -----> This is Vlan number 4500(config-vlan-config)#ip flow monitor IPV4-FLOW input
Similarly we will apply to L3 port :
interface GigabitEthernet 0/1 ip flow monitor IPV4-FLOW input
Show Commands to check Flexible Netflow is configured correctly :
4500#show flow ? exporter Flow Exporter information interface Flow interface information internal Show the flow fields monitor Flow Monitor information record Show Flow Record configuration
You can check different parameters and configuration by using "show flow " command.
Thanks for reading my short post regarding Flexible Netflow on Cisco 4500 Switch.
nice
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