Additional Configuration Tasks on Datalinks

This section describes other common configuration procedures that have become simplified by using the dladm command, such as performing dynamic reconfiguration (DR) and working with STREAMS modules.

How to Replace a Network Interface Card With Dynamic Reconfiguration

This procedure applies only to systems that support dynamic reconfiguration (DR). It shows how DR is now facilitated by the separation of the network link configuration from the network hardware configuration. You no longer need to reconfigure your network links after you complete DR. Instead, you just transfer the link configurations of the removed NIC to be inherited by the replacement NIC.

Before You Begin

Procedures to perform DR vary with the type of system. Make sure that you complete the following first:

• Ensure that your system supports DR.

• Consult the appropriate manual that describes DR on your system.

  To locate current documentation about DR on Sun servers, search for dynamic reconfiguration on http://docs.sun.com

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  Note - The following procedure refers only to aspects of DR that are specifically related to the use of flexible names for datalinks. The procedure does not contain the complete steps to perform DR. You must consult the appropriate DR documentation for your system.

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1. Become an administrator.

   For more information, see How to Obtain Administrative Rights in System Administration Guide: Security Services.

2. (Optional) Display information about physical attributes of datalinks currently on the system.

   # dladm show-phys

3. Perform the DR procedures as detailed in your system's documentation to remove a NIC and then insert a replacement NIC.

   Consult your system's DR documentation to perform this step.

   After you have installed the replacement NIC, proceed to the next step.

4. Make sure that the replacement NIC is not being referenced by other configurations in the system.

   For example, the replacement NIC you install is bge0. If a file /etc/hostname.bge0 exists in the system, remove that file.

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   Note - If the IP interface in the system was configured by using the ipadm command, this step is unnecessary. With the ipadm command, configuration is persistent, and the /etc/hostname.interface file is not required nor should exist.

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5. Transfer the link configuration of the removed NIC to the replacement NIC.

   # dladm rename-link replacementNIC-linkname removedNIC-linkname

   replacementNIC-linkname

   Refers to the default link name of the replacement NIC upon installation. When you insert a NIC into a system for the first time, the NIC's link name is hardware-based, such as bge0.

   removedNIC-linkname

   Refers to the customized link name of the NIC that you removed.

6. Complete the DR process by enabling the new NIC's resources to become available for use by the operating system.

   For example, you use the cfgadm command to configure the NIC. For more information see the cfgadm(1M) man page.

7. (Optional) Display link information.

   For example, you can use either dladm show-phys or dladm show-link to show information about the datalinks.

Example 7-10 Replacing a Network Card

This example shows how a bge card with link name net0 is replaced by a e1000g card. The link configurations of net0 are transferred from bge to e1000g after e1000g is connected to the system.

# dladm show-phys
LINK          MEDIA        STATE     SPEED     DUPLEX     DEVICE
subitops1     Ethernet     up        100Mb     full       nge3
net0          Ethernet     up        100Mb     full       bge0

You perform the DR-specific steps such as using cfgadm to disconnect bge and then install e1000g. Then the procedure continues.

# ls /etc/hostname.*
hostname.e1000g0

# rm /etc/hostname.e1000g0
# dladm rename-link e1000g0 net0

# dladm show-phys
LINK        MEDIA        STATE     SPEED     DUPLEX     DEVICE
subitops1   Ethernet     up        100Mb     full       nge3
net0        Ethernet     up        100Mb     full       e1000g0

Configuring STREAMS Modules on Datalinks

If necessary, you can set up to eight STREAMS modules to be pushed on top of a datalink. These modules are typically used by third-party networking software such as virtual private networks (VPNs) and firewalls. Documentation about such networking software is provided by the software vendor.

The list of STREAMS modules to push on a specific datalink is controlled by the autopush link property. In turn, the value of the autopush link property is set by using the dladm set-linkprop subcommand.

A separate autopush command can also be used to set the STREAMS autopush modules on a per-driver basis. However, the driver is always bound to the NIC. If the datalink's underlying NIC is removed, then the link's autopush property information becomes lost as well.

To configure the STREAMS modules to be pushed on top of a datalink, use the dladm set-linkprop command in preference over the autopush command. If both per-driver and per-link types of autoputsh configuration exist for a specific datalink, the per-link information that is set with dladm set-linkprop is used and the per-driver information is ignored.

How to Set STREAMS Modules on Datalinks

The following procedure describes how to configure STREAMS modules with the dladm set-linkprop command.

1. Become an administrator.

   For more information, see How to Obtain Administrative Rights in System Administration Guide: Security Services.

2. Push the modules to the stream when the link is opened.

   # dladm set-linkprop -p autopush=modulelist link

   modulelist

   Specifies the list of modules that you want to be automatically pushed on to the stream. A maximum of eight modules can be pushed over a link. These modules are pushed in the order that they are listed in modulelist. Separate the modules in the list by using dots as delimiters.

   link

   Specifies the link on which the modules are pushed.

Example 7-11 Setting the autopush Link Property

In this example, you push the vpnmod and bufmod modules on top of the link net0. The link's underlying device is bge0.

# dladm set-linkprop -p autopush=vpnmod.bufmod net0

If you later replace the bge card with ce, you can switch to the new datalink without needing to reconfigure the autopush settings. You just assign the link name to the new datalink, as follows:

# dladm rename-link ce0 net0

How to Obtain autopush Link Property Settings

1. Become an administrator.

   For more information, see How to Obtain Administrative Rights in System Administration Guide: Security Services.

2. Display autopush link property settings.

   # dladm show-linkprop -p autopush [link]

   If you do not specify link, then the information for all configured links is displayed.

How to Remove autopush Link Property Settings

1. Become an administrator.

   For more information, see How to Obtain Administrative Rights in System Administration Guide: Security Services.

2. Remove the autopush link property settings of a specific datalink.

   # dladm reset-linkprop [-t] -p autopush link

   Use the -t option to remove the property settings temporarily. The settings are restored when you reboot the system.