Table of Contents

General description

It is strongly recommended to use only physical network adapters for CHARON-VAX networking to gain maximum performances. In situations where the host has only one network adapter, you can use Linux virtual network Interfaces ("TUN/TAP") and map individual CHARON-VAX instances to their own virtual interfaces.

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• Using the "ncu" utility
• Manually

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Using "ncu" utility to establish CHARON virtual network

Login a root and start the "ncu" utility:

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Manual configuration of CHARON virtual network

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Host preparation

1. Login as "root" user.
   
   

2. Configure the physical network interface to run in promiscuous mode using the following command. This interface will be dedicated to the whole network bridge (created later).

   # ifconfig eth<N> 0.0.0.0 promisc up

   The promiscuous mode allows the physical (or virtual) network interface to accept the entire volume of incoming packets. This mode is essential for consistency of the information transfer.
   
   

3. In case the firewall is enabled on the host system, the following command should be executed to allow the bridge to forward IP packets:

   Red Hat Enterprise Linux 6.x:

   
   

   # /sbin/iptables -I FORWARD -m physdev --physdev-is-bridged -j ACCEPT

   This command can also be performed from the bridge configuration script. It has to be executed each time the iptables service is (re)started.

   It is also possible to make this setting system-wide. Either:

   1. Issue the given command from the firewall control panel.

   2. Add the following line to the end of the "/etc/sysconfig/iptables" file:

      
      

      -I FORWARD -m physdev --physdev-is-bridged -j ACCEPT

      
      

   Red Hat Enterprise Linux 7.x and CentOS 7.x:

   
   

   # firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 1 -m physdev --physdev-is-bridged -j ACCEPT # firewall-cmd --permanent --direct --add-rule ipv6 filter INPUT 1 -m physdev --physdev-is-bridged -j ACCEPT # firewall-cmd --reload

   
   

Virtual interface creation

The creation of the desired number of virtual network interfaces (TAPs) can be performed in the following way:

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Bridge creation

To interconnect the physical and virtual network interfaces created in the previous step, the network bridge must be introduced in the following way:

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