How to add or remove a network interface from an IBM i virtual machine (VM)

Since IBM PowerVC Version 1.2.2, IBM PowerVC can dynamically add a network interface controller (NIC) to a VM or remove a NIC from a VM. IBM PowerVC does not set the IP address for new network interfaces that are created after the machine deployment. Any removal of a NIC results in freeing the IP address that was set on it. You must remove and readd the IBM i VM network interface if you choose to disconnect the Power Virtual Server IBM i VM from a public network.

When you toggle a public network off and then on, the Power Virtual Server user interface regenerates new internal and external IP addresses. You need to check the Power Virtual Server user interface for the new internal IP address to complete this procedure.

Removing a network interface from an IBM i VM

Learn how to change the TCP/IP address of your IBM i VM. You can change your system's TCP/IP address while the TCP/IP is active. However, you must deactivate the TCP/IP interface. For a complete set of instructions, see Changing the TCP/IP Address of the IBM System i System.

Before you change a TCP/IP address, determine whether it has any associated routes. Choose Option 8 from the NETSTAT *IFC screen. It's a good idea to select Option 5 to display the details of the route. Remember to press F6 to print the details for reference for when the route must be readded. This step should be done for all of the non-*DIRECT routes that are listed on the screen.
Run the CFGTCP command, and select Option 2 to work with your TCP/IP routes. Select Option 4 next to the routes you'd like to remove. All of that communication that is going over the route is terminated after you remove it.
To make the actual changes, you must deactivate and remove the interface before you add it. Select Option 10 next to the interface you'd like to deactivate on the NETSTAT *IFC screen.

To remove the interface after deactivation, run the CFGTCP command and select Option 1 from that menu. Select Option 4 next to the interface you'd like to remove. Removing a network interface:

                    Work with TCP/IP Interfaces
                                                                    System: RCHASSLH
Type options, press Enter. 
1=Add   2=Change    4=Remove    5=Display   9=Start   10=End

          Internet          Subnet            Line                Line
Opt       Address           Mask              Description         Type
___       9.5.186.23        255.255.255.0     SITETRN             *TRLAN
___       9.5.186.222       255.255.255.0     SITETRN             *TRLAN
_4_       10.10.10.1        255.255.255.0     SITETRN             *TRLAN
___       127.0.0.1         255.0.0.0         *LOOPBACK           *NONE





                                                                              Bottom
F3=Exit       F5=Refresh      F6 Print list     F11-Display interface status
F12=Cancel    F17=Top         F18=Bottom

You must vary off the Line description (LIND) after you remove the interface.

Adding a network interface to an IBM i VM

After you remove the routes and interfaces, create the new configuration in the reverse order. To get to the ADDTCPIFC screen, run the CFGTCP command and select Option 1. Most configurations require you to update only the first three fields.
Add the new internal IP address you obtained from the Power Virtual Server user interface (you can type over the quotation marks) to the Internet address field.
Add the new subnet mask to the Subnet mask field.
Complete the remaining fields by using your reference printout. The LIND must be the same as the LIND defined on the removed interface.
After you add the interface, activate it from the NETSTAT *IFC screen by selecting Option 9.
To verify that the new interface is active, ping the address from the command line. If the ping responds, the interface is working correctly.
Finally, add the new routes that use this interface (if any). You can add new routes by selecting Option 2 from the CFGTCP menu. Type 1 in the Opt column to add a new route, and press the Enter key.

Adding a network interface:

```
                            Add TCP/IP Interface (ADDTCPIFC)

Type choices, press Enter

Internet address.   .   .   .   .   .   .   .   .   . > .   .  
Line description.   .   .   .   .   .   .   .   .   .   ____________    Name, *LOOPBACK..
Subnet mask .   .   .   .   .   .   .   .   .   .   .   ____________
Associated local interface. .   .   .   .   .   .   .   *NONE
Type of service.    .   .   .   .   .   .   .   .   .   *NORMAL         *MINDELAY, *MAXTHRPUT..
Maximum transmission unit.  .   .   .   .   .   .   .   *LIND           576-16388, *LIND
Autostart.  .   .   .   .   .   .   .   .   .   .   .   *YES            *YES,   *NO
PVC logical channel identifier. .   .   .   .   .   .   ____________    001-FFF
                             + for more values          ____________
X.25 idle circuit timeout.  .   .   .   .   .   .   .   60              1-600
X.25 maximum virtual circuits.  .   .   .   .   .   .   64              0-64
X.25 DDN interface. .   .   .   .   .   .   .   .   .   *NO             *YES,   *NO
TRLAN bit sequencing.   .   .   .   .   .   .   .   .   *MSB            *MSB,   *LSB
```