Configuring a Packet Forwarder to Communicate with the DNCA

To process web traffic in a cloud-based environment, a packet forwarder must be configured to transmit data to a central DNCA that is operating on a virtual machine.

Before you begin

The following prerequisites must be completed before you configure the packet forwarder software.

All installation and configuration operations must be completed using the root user account. Using the sudo command may not provide sufficient permissions to allow system parameter modifications and might cause an incomplete or incorrect installation.

About this task

Use the following steps to configure the packet forwarder and DNCA for communication in your cloud-based environment.

Procedure

Locate /usr/local/dncauser/etc/fwdr-conf.xml on the reverse proxy server or on the virtual web server that is hosting the packet forwarder transmitter.
Back up the existing configuration file by copying /usr/local/dncauser/etc/fwdr-conf.xml to a backup directory.
If your configuration file becomes corrupted or invalid, you can restore from your backup or create a new configuration file from fwdr-conf-defaults.xml. fwdr-conf-defaults.xml contains the default configuration settings for the packet forwarder.
Edit the /usr/local/dncauser/etc/fwdr-conf.xml.
You can use the vi editor or another text editor to edit the configuration file.
Locate the <PrimaryInterface> tag and edit the virtual NIC device name for the packet forwarder.
The packet forwarder captures the traffic from the web server. For most installations, eth0 is used as the device name.
Edit the port numbers to reflect the traffic ports that are used for your server.
The default capture traffic filter rule is defined to listen to port 80 and 443 traffic.
Example port settings:
```
<ListenTos>
<ListenTo>
<Port>80</Port>
<Port>443</Port>
</ListenTo>
</ListenTos>
```
Locate the Delivery tag and edit the delivery network connection for the packet forwarder. This connects the packet forwarder to the centralized DNCA VM instance.
Example delivery network connection settings:
```
<Peers>
<Peer>
<Address>127.0.0.1</Address&gt>
<Port>1888</Port>
</Peer>
</Peers>
```
Locate and edit the <Address> and <Port> tag match the assigned internal IP address and port of the DNCA that is installed on the virtual machine.
Example setting for the DNCA VM internal IP address:
Note: The <Port> tag defines the port number of the base network connection. This is a base port number where it defines the block of port numbers that can be used for the number of web server instances that can be provisioned. For example, if you know that there will be a maximum of five web-server instances that can be dynamically provisioned, then the block of ports that are used start with 1888. In this example, port numbers 1888 - 1892 would be used based on the maximum of five instances.
```
<Peers>
<Peer>
<Address>127.0.0.1</Address>
<Port>1888</Port>
</Peer>
</Peers>
```
Locate and edit the <MaxRotatePeers> tag to define the maximum number of web server instances that can be dynamically provisioned. The default is set to 1 for just one web-server instance where there are no other instances of the packet forwarder used in the web server tier.
Note: If you are statically assigning a fixed number of web server instances with associated packet forwarders, then the <MaxRotatePeers> would remain set to the default value of 1. Each packet forwarder has to configured with a unique port number to identify a unique network connection to the centralized DNCA VM instance. The port numbers must be assigned in sequential order. This is required by the socket receiver for the DNCA when it is configured for the packet forwarder's network connections. If you decide to start with port number 1888 for the first packet forwarder, then defining five of them would be 1888 through 1892.
Save your changes to the configuration file.
You must configure a packet forwarder receiver instance for each Packet Forwarder transmitter instance that you have deployed. For more information, see Configuring a Packet Forwarder Receiver and the DNCA to Receive Forwarded Packets.

What to do next

Once the packet forwarder is running, you can also perform the following actions:

Check the status of a packet forwarder, by running service pktfwdr status.
Stop a packet forwarder, by running service pktfwdr stop.
View the statistics for a packet forwarder, by running dcxstats -p.