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User Guide for the Cisco Network Analysis Module (NAM) Traffic Analyzer, 5.0
OL-22617-01
Chapter 2 Setting Up The NAM Traffic Analyzer
Traffic
• Deleting ERSPAN Data Sources Using the Web GUI, page 2-14
• Deleting ERSPAN Data Sources Using the CLI, page 2-15
• Configuring ERSPAN on Devices, page 2-16
Enabling Auto-Creation of ERSPAN Data Sources Using the Web GUI
There is a convenient “auto-create” feature for data sources, which is enabled by default. With the
auto-create feature, a new data source will automatically be created for each device that sends ERSPAN
traffic to the NAM, after the first packet is received. Manual creation of ERSPAN data sources using the
NAM GUI or the CLI is typically not necessary. When manually creating a data source, you may specify
any name you want for the data source. A data source entry must exist on the NAM in order for it to
accept ERSPAN packets from an external device.
Auto-created ERSPAN data sources will be assigned a name in the format ERSPAN-<IP
Address>-ID-<Integer>, where IP Address is the IP address of the sending device, and Integer is the
Session-ID of the ERSPAN session on that device. For example, device 192.168.0.1 sending ERSPAN
packets with the Session ID field set to 12 would be named “ERSPAN-192.168.0.1-ID-12.” You can edit
these auto-created data sources and change the name if desired.
One device can be configured to send multiple separate ERSPAN sessions to the same NAM. Each
session will have a unique Session ID. The NAM can either group all sessions from the same device into
one data source, or have a different data source for each Session ID. When data sources are auto-created,
they will be associated with one particular Session ID. When manually created, you can instruct the
NAM to group all traffic from the same device into one data source. If you check the Session check box,
and enter a Session ID in the Value field, the data source will only apply to that specific session. If you
leave the check box unchecked, all ERSPAN traffic from the device will be grouped together into this
data source, regardless of Session ID.
To configure the NAM to automatically create data sources when it receives ERSPAN packets from an
external device, use the following steps. Remember however, that the auto-create feature is turned on by
default, so these steps are typically not necessary.
Step 1 Click Setup > Traffic > NAM Data Sources.
Step 2 Click the Auto Create button on the bottom left of the window.
Step 3 Check the ERSPAN check box to toggle auto-creation of ERSPAN data sources to “on”.
Step 4 Click the Submit button.
Enabling Auto-Creation of ERSPAN Data Sources Using the CLI
Configuration of the auto-create feature is also possible using the NAM CLI. Because the auto-create
feature is turned on by default, in most cases these steps are not necessary.
To configure the NAM to automatically create data sources when it receives ERSPAN packets from an
external device, use the "autocreate-data-source" command as follows:
root@172-20-104-107.cisco.com# autocreate-data-source erspan
ERSPAN data source autocreate successfully ENABLED