DPOD can be configured with two network interfaces:

...

1. Copy the network interface MAC address as displayed in the "ifconfig"   command output after the attribute "ether":
   
   

2. change Change directory to /etc/sysconfig/network-scripts:
   
   

   Code Block
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   cd /etc/sysconfig/network-scripts

   
   

3. duplicate the Duplicate eth0 (first network interface) network interface configuration file for the new network interface file (eth1):
   
   

   Code Block
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   cp ifcfg-eth0 ifcfg-eth1

   
   

4. Edit the new file (ifcfg-eth1) and alter the following attributes based on the new network interface properties
   
   

   Code Block
   DEVICE=eth1 BOOTPROTO=static ONBOOT=yes NM_CONTROLLED=no HWADDR=00:0c:29:14:7a:88 IPADDR=192.168.1.178 NETMASK=255.255.255.0 USERCTL=no DNS1=8.8.8.8 DNS2=8.8.4.4 IFCONFIG_OPTS="txqueuelen 10000"

   
   DEVICE     : The network interface device name should be eth1
   HWADDR  : The network interface MAC address as displayed at section 1.
   NETMASK : The network mask based on the new interface properties (the network administrator should supply this information)
   
   

5. Restart the network service by entering the following command:

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   service network restart The command output should be : Restarting network (via systemctl): [ OK ]

   
   

6. Use the command "ifconfig" to make sure the new network interface is up and configured with the correct IP address:
   
   
   If the new IP address is not displayed restart the server.
7. sdf

Configure Routing

In order to support the second network interface, a new routing table and routing rules should be defined.

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1. Edit the file /etc/iproute2/rt_tables and add new routing table entry with id "1" named "rt1":
   
   

   
   

   
   

2. In order to add new routing entry to the new routing table use the "ip route" command.
   This command will add new temporary entry to the routing table.
    

3. Add a default gateway entry (should be executed only once)
   
   

   Code Block
   ip route add default via <interface default gateway> dev <interface name> table <routing table name>

   
   Example : For adding the default gateway 192.168.1.1 to interface eth1:

   
   

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   ip route add default via 192.168.1.1 dev eth1 table rt1

   
   

   Note
   Adding a default gateway to a network interface should be executed only once.

   
   

4. Add a routing entry  entry (should be executed as needed for every monitored device):
   
   

   Code Block
   ip route add <destinamtion ip address or subnet> dev <interface name> table <routing table name>

   
   Example : For adding the route entry to subnet 192.168.1.x to interface eth1

   Code Block
   language bash theme RDark
   ip route add 192.168.1.0/24 dev eth1 table rt1

   
   

   Note
   Adding specific routing entry should be executed as needed for every monitored device

   
   

5. In order to make these entries permanent edit the file /etc/sysconfig/network-scripts/route-<interface name> and add the following:

   Code Block
   default via <interface default gateway> dev <interface name> table <routing table name> <destinamtion ip address or subnet> dev <interface name> table <routing table name>

   
   For example : Create new permanent routing file for interface eth1 and add the entries used at previous examples :

   Code Block
   default via 192.168.1.1 dev eth1 table rt1 192.168.1.0/24 dev eth1 table rt1

   
   

6. To confirm that the new routing table includes the new routing entries use the following command to display the content of the table :
   
   

   Code Block
   ip route show tab <routing table name>

   
   For example : To display the content of table rt1:
   
   

   Code Block
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   ip route show tab rt1 The output should be : default via 192.168.1.1 dev eth1 192.168.1.0/24 dev eth1 scope link

   
   

Create a New Routing Rule

The routing rule instruct instructs the operating system when to use the new routing table.

1. In order to add a new routing rule entry to the new routing table use the "ip rule" command.
   This command will add a new temporary rule entry .

   Code Block
   ip rule add from <source ip address or subnet> table <routing table name> ip rule add to <destination ip address or subnet> table <routing table name>

   
   For example : The routing rule for monitored device 192.168.1.120 are :

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   ip rule add from 192.168.1.120/32 table rt1 ip rule add to 192.168.1.120/32 table rt1

   The specific IP address can be replaced with subnet if subnet rule is appropriate : 192.168.1.0/24
   
   

2. In order to make these entries permanent edit the file /etc/sysconfig/network-scripts/rule-<interface name> and add the following :
   
   

   Code Block
   from <source ip address or subnet> table <routing table name> to <destination ip address or subnet> table <routing table name>

   For example : The routing rule for monitored device 192.168.1.120 are :
   
   

   Code Block
   from 192.168.1.120/32 table rt1 to 192.168.1.120/32 table rt1

   
   

3. To confirm that the new routing rules entries added use the following command to display them :
   
   

   Code Block
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   ip rule show The output should include the following lines: 32764: from all to 192.168.1.120 lookup rt1 32765: from 192.168.1.120 lookup rt1

   
   

...

1. Restart the server.
2. After the server is up again login via SSH.
   Use the "ip route show tab" command and the "ip rule show" command make sure the routing entries and the routing rule persists after the restart.

3. Confirm the needed network connectivity to the monitored device:
   Open new CLI session via SSH and start capture network traffic passing through eth1 to the wanted monitored device.
   The following command will capture network traffic to 192.168.1.120:
   
   

   Code Block
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   tcpdump -i eth1 host 192.168.1.120

   
   On the second SSH session run telnet command to test connectivity to the monitored device using port 5550 (XML Management Interface Port):
   
   

   Code Block
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   telnet 192.168.1.120 5550

   The output of the tcpdump command should look similar to the following:
   The source of the tcp connection is the new eth1 ip address and the destination is the monitored device ip address: