2    Basic Network Connections

Digital recommends that you use the Network Configuration application of the Common Desktop Environment (CDE) Application Manager for configuring network components on systems with graphics capabilities. You can configure the following components:

• Network interfaces (Ethernet, FDDI, and Token Ring)

• Static routes file (/etc/routes)

• gated daemon

• routed daemon

• rwhod daemon

• IP router

• Hosts file (hosts)

• Host equivalent file (hosts.equiv)

• Networks file (/etc/networks)

See netconfig(8X) for more information on the Network Configuration application.

To invoke the Network Configuration application, log in as root, do the following:

1. Click on the Application Manager icon on the CDE front panel.

2. Double-click on the System_Admin application group icon.

3. Double-click on the Digital System_Management_Utilities application group icon.

4. Double-click on the Configuration application group icon.

5. Double-click on the Network Configuration application icon. The Network Configuration main window appears, showing available network components and configured network components.

To exit the Network Configuration application, choose File then Exit.

Note

For systems without graphics capabilities, you can use the netsetup utility. See netsetup(8) for more information.

The Network Configuration application also has an extensive online help system. You can use it instead of the instructions in this section to configure network components on your system.

2.3.1    Configuring Network Interfaces

To configure the Ethernet, FDDI, or Token Ring network interface, do the following:

1. In the Network Configuration Main Window, select an interface from the Available Network Components list box. All network adapters that are installed on the system are listed.

2. Click on Configure. The Configuring Interface Dialog Box for the selected interface appears.

3. Set the Interface Configuration Enable check button to the ON position to enable the interface on the next reboot.

4. Enter the name for the interface in the Host Name input text field. If this is the first or only network interface you are configuring and there is a default host name, the utility displays the default.

5. For the Ethernet interface, do the following:

   1. If you are to obtain the IP address data from the DHCP server, set the Use DHCP Server radio button to the ON position. Otherwise, set the User Supplied Value radio button to the ON position and enter the IP address and network mask data in the appropriate input text fields.

   2. Click on the down arrow button. This expands the window to display the advanced configuration parameters for the selected interface.

   3. Click on the check button for Multicast to enable the reception of multicast packets. See map-mbone(7) for more information on multicast routing.

   4. Click on the check boxes for the appropriate interface options.

   5. Go to step 8.

6. For the FDDI interface, do the following:

   1. If you are to obtain the IP address data from the DHCP server, set the Use DHCP Server radio button to the ON position. Otherwise, set the User Supplied Value radio button to the ON position and enter the IP address and network mask data in the appropriate input text fields.

   2. Click on the down arrow button. This expands the window to display the advanced configuration parameters for the selected interface.

   3. Click on the check boxes for the appropriate interface options.

   4. Enter the broadcast address for the interface in the Broadcast Address input text field.

   5. Go to step 8.

7. For the Token Ring interface, do the following:

   1. Enter the IP address for the host device in the IP Address input text field.

   2. Enter the mask variable for the interface in the Network Mask input text field.

   3. Click on the button in option box to display a menu of token ring adapter speeds. Select the appropriate adapter speed: 4 or 16.

   4. Click on the down arrow button. This expands the window to display the advanced configuration parameters for the selected interface.

   5. Enter the broadcast address for the interface in the Broadcast Address input text field.

   6. Go to step 8.

8. Click on Commit.

9. Click on OK to save the changes and start the interface.

10. Click on Close to close the Configuring Interface Dialog Box.

The Network Configuration application also enables you to modify and delete network interface. See the application online Help for additional information.

2.3.2    Configuring the Rwho Daemon

To configure the rwhod daemon, do the following:

1. In the Network Configuration Main Window, select Rwho Daemon from Available Network Components list box.

2. Click on Configure. The Configuring rwho Daemon dialog box appears.

3. Set the rwhod Daemon Enable check box to the ON position to start the rwhod daemon the next time the system is rebooted.

4. Click on the appropriate rwhod flag.

5. Click on Commit.

6. Click on OK to save the changes and start the daemon.

7. Click on Close to close the Configuring rwho Daemon dialog box.

The Network Configuration application also enables you to modify and delete the rwhod daemon. See the application online Help for additional information.

2.3.3    Configuring the Route Daemon

To configure the routed daemon, do the following:

1. In the Network Configuration Main Window, select Route Daemon from Available Network Components list box.

2. Click on Configure. The Configuring Route Daemon dialog box appears.

3. Set the routed Daemon Enable check box to the ON position to start the routed daemon the next time the system is rebooted.

4. Set the routed flags to the ON position as needed.

5. Set the Supply RIP Data radio button to the ON position if routed is to run on a gateway host and supply Routing Information Protocol (RIP) data. Set the Run Quietly radio button to the ON position if routed is not to supply RIP information.

6. Click on Gateways File. The Gateways dialog box appears. Do the following:

   1. In the Dest Type field, set the net check box to the ON position if if the destination is a network. Set the host check box to the ON position if the destination is a host.

   2. Enter the destination name, IP address, or "default" in the Destination input text box.

   3. Enter the name or IP address of the gateway host in the Gateway input text box.

   4. Enter the hop count in the Hop Count input text box.

   5. Set one of the Route Type check boxes to the ON position.

   6. Click on Add. Repeat steps 1 through this step in this sublist for additional gateways.

   7. Click on Commit and Close to save the changes and close the Gateways dialog box.

7. Click on Commit.

8. Click on OK to save the changes and start the daemon.

9. Click on Close to close the Configuring routed dialog box.

The Network Configuration application also enables you to modify and delete the routed daemon and entries in the gateways file. See the application online Help for additional information.

See routed(8) and gateways(4) for more information.

2.3.4    Configuring the gated Daemon

To configure the gated daemon, do the following:

1. In the Network Configuration Main Window, select gated from Available Network Components list box.

2. Click on Configure. The Configuring gated dialog box appears.

3. Set the gated Daemons Enable check box to the ON position to start the gated daemon the next time the system is rebooted.

4. Enter the file name of the gated configuration file in the Config File input text field.

   Note

   To configure the gated daemon, you must set up the /etc/gated.conf file in the format specified in gated.conf(4). A default /etc/gated.conf file is provided when you install the software.

5. Click on Commit.

6. Click on OK to save the changes and start the daemon.

7. Click on Close to close the Configuring gated dialog box.

The Network Configuration application also enables you to modify and delete the gated daemon. See the application online Help for additional information.

See gated(8) and gated.conf(4) for more information.

2.3.5    Configuring the System as an IP Router

In order to function as an IP router, your system must have two network interfaces installed and configured and must have routed or gated configured. To configure the system as an IP router, do the following:

1. In the Network Configuration Main Window, select IP Router from Available Network Components list box.

2. Click on Configure. The Configuring IP Router dialog box displays.

3. Set the IP Router Enable check box to the ON position to run the system as an IP router the next time the system is rebooted.

4. Click on Commit and click on Close. This saves current changes and closes the dialog box.

The Network Configuration application also enables you to deconfigure the system as an IP router. See the application online Help for additional information.

2.3.6    Configuring the Static Routes File

To configure the routes file, you add entries (static routes), to the routes file. Do the following:

1. In the Network Configuration Main Window, select Static Routes File from Available Network Components list box.

2. Click on Configure. The Static Routes dialog box appears.

3. Set one of the Destination Type check boxes to the ON position.

4. For host and net, enter the full name or IP address of the destination network or host in the Destination input text field.

5. Set one of the Route Via check boxes to the ON position. Click on the Gateway check box if the route is through a gateway; click on the Interface check box if the route is through an interface.

6. For a gateway, enter the full name or IP address of the gateway host to which messages will be forwarded in the Gateway input text field.

7. Click on Add. This accepts the entry. Repeat steps 3 through 7 for additional static routes.

8. Click on Commit and click on Close. This saves current changes and closes the dialog box.

The Network Configuration application also enables you to modify and delete entries in the routes file. See the application online Help for additional information.

See routes(4) for more information.

2.3.7    Configuring the hosts File

To configure the hosts file, do the following:

1. From the Network Configuration Main Window, select Host File from Available Network Components list box.

2. Click on Configure. The Hosts dialog box appears.

3. Enter the official host name in the Host Name input text field.

4. Enter the IP address of the new host in the Host Address input text field.

5. If an unofficial name or names (alias) are assigned to the new host, enter the names in the Aliases input text field.

6. Click on Add. This accepts the entry. Repeat steps 3 through 5 for additional hosts.

7. Click on Commit and Close to update the hosts file and close the Hosts dialog box.

The Network Configuration application also enables you to modify and delete entries in the hosts file. See the application online Help for additional information.

See hosts(4) for more information.

2.3.8    Configuring the hosts.equiv File

To configure the hosts.equiv file, do the following:

1. In the Network Configuration Main Window, select Host.equiv File from the Available Network Components list box.

2. Click on Configure. The Hosts.equiv dialog box appears.

3. Enter the host name in the Host name text field.

   Note

   If the host is not on the network, you cannot add the host.

4. Enter the name of a user on the remote host.

5. Click on Add. This accepts the entry. Repeat steps 3 and 4 for additional hosts.

6. Click on Commit and Close to update the /etc/hosts.equiv file and close the Hosts.equiv dialog box.

The Network Configuration application also enables you to modify and delete entries in the hosts.equiv file. See the application online Help for additional information.

See hosts.equiv(4) for more information.

2.3.9    Configuring the networks File

To configure the networks file, do the following:

1. In the Network Configuration Main Window, select Network File from the Available Network Components or Configured Network Components list box.

2. Click on Configure. The Networks dialog box appears.

3. Enter the official network name in the Net Name input text field.

4. Enter the IP address of the network in the Net Address input text field.

5. If an unofficial name (alias) is assigned to the new network, enter the aliases in the Aliases input text field.

6. Click on Add to accept the entry. Repeat steps 3 through 5 for additional networks.

7. Click on Commit and Close to update the /etc/networks file and close the Networks dialog box.

The Network Configuration application also enables you to modify and delete entries in the networks file. See the application online Help for additional information.

See networks(4) for more information.

2.4    Enabling Access Filtering on an Interface

Interface access filtering provides a mechanism for detecting and preventing IP spoofing attacks. To enable interface access filtering on an interface, do the following:

1. Create an /etc/ifaccess.conf file and add entries against which the source address of input packets are checked.

2. Use the ifconfig command with the +filter parameter to enable access filtering on the network interface.

See ifaccess.conf(4) and ifconfig(8) for more information.

2.5    Monitoring the Local Host's Status

You use the netstat command to monitor the status of the local host by viewing the contents of network-related data structures. You can select several forms of display; each allows you to specify the type of information you want to emphasize.

To monitor the local host's network status, use the netstat command with the following syntax:

netstat [ options... ]

Table 2-1 shows the netstat command options.

Table 2-1: Options to the netstat Command

The -I option provides statistics for a specific interface. See Appendix B for an example of using the -I option to monitor Ethernet, Fiber Distributed Data Interface (FDDI), and token ring interfaces, and a description of the counters, status, and characteristics. The -i option gives statistics on each configured network interface. Outgoing packet errors (Oerrs) indicate a potential problem with the local host. Incoming errors (Ierrs) indicate a potential problem with the network connected to the interface.

See netstat(1) for more information on this command.

The following example shows normal output (no Ierrs or Oerrs) from the netstat command with the -i option:

%  netstat -i

Name  Mtu   Network   Address       Ipkts Ierrs    Opkts Oerrs  Coll
ln0   1500  <Link>                8324125     0  8347463     0 237706
ln0   1500  16.31.16  host1       8324125     0  8347463     0 237706
fza0* 4352  <Link>                      0     0        0     0    0
sl0*  296   <Link>                      0     0        0     0    0
sl1*  296   <Link>                      0     0        0     0    0
tra0  4092  <Link>                     34     0       20     0    0
tra0  4092  16.40.15  host21           34     0       20     0    0
lo0   1536  <Link>                 909234     0   909234     0    0
lo0   1536  loop      localhost    909234     0   909234     0    0

2.6    Displaying and Modifying the FDDI Parameters

You use the fddi_config command to display and modify the FDDI adapter parameters.

To display the FDDI adapter parameters, use the fddi_config command with the following syntax:

fddi_config -i interface_name -d

To modify the FDDI adapter parameters, do the following:

1. Log in as root.

2. Use the fddi_config command and options as follows:

   fddi_config [ options... ]

Table 2-2 shows the fddi_config command options.

Table 2-2: Options to the fddi_config Command

See fddi_config(1) for more information on this command.

The following example shows how to display the FDDI interface parameters you can set:

%  /usr/sbin/fddi_config -i fza0 -d

fza0 ANSI FDDI settable parameters
Token Request Time:                0.0000 ms
Valid Transmission Time:           0.0000 ms
LEM Threshold:                     0
Restricted Token Timeout:          15.8314 ms
Ring Purger State:                 (null)
fza0 Full Duplex Mode: Disabled
fza0 Counter Update Interval: 10 sec

The following example shows how to change the Token Request Time (TRT) value for the fza0 interface to 10.2:

#  fddi_config -t10.2 -i fza0

The following example shows how to turn the ring purger off:

#  fddi_config -p 0 -i mfa0

2.7    Managing Token Ring Source Routing

Source routing is a bridging mechanism that systems on a token ring LAN use to send messages to a system on another interconnected token ring LAN. Under this mechanism, the system that is the source of a message uses a route discovery process to determine the optimum route over token ring LANs and bridges to a destination system. The source system stores the optimum routes in its source routing table.

When the system is booted with the DETRA adapter installed and configured, token ring source routing is initialized by default. To manage token ring source routing, use the srconfig command and options as follows:

srconfig options...

Table 2-3 shows the srconfig command options. All srconfig command options are case insensitive; type them in uppercase, lowercase, or mixed case. The short form for each flag is indicated by uppercase letters.

Table 2-3: Options to the srconfig Command

Table notes:

1. Requires superuser privileges.

See srconfig(8) for more information on this command.

The following example increases the number of routing table entries from 1024 to 1280 by using the shortened form of the -SetMaxEntry option:

#  srconfig -setm 1280

Current SR Table size is : 1024
New SR Table size is : 1280

The following example displays the source routing attributes by using the shortened form the the -RAttr option:

#  srconfig -ra

Source Routing is enabled
Current SR Aging Timer     : 120
Current SR Discovery Timer : 10
Current SR Table size is   : 1024

The following example displays the source routing counters by using the shortened form of the -RCounter option:

#  srconfig -rc

ARE Frames Sent          : 00000001
ARE Frames received      : 00000000
Route Discovery Failures : 00000001

The following example displays all entries, with MAC addresses in canonical form, in the source routing table, by using the shortened form of the -RTable option. The backslash (\) character is included for formatting purposes and does not appear in the actual output.

#  srconfig -rt

Target Node MAC Address 00-00-0C-01-08-E9 (ip = 130.180.4.3) \
Have Route  [1]
Routing Information: SRF, length 8, direction 0,largest frame \
4472 octets  [2]
Route Descriptors: 021C 7FFC 0220 0000 0000 0000 0000 0000    [3]

 

Target Node MAC Address 00-00-C9-10-1B-F5 On Ring    [4]

 

Target Node MAC Address 08-00-2B-2C-F1-F9 (ip = 130.180.4.2)  \ 
Stale (Have Route)   [5]
Routing Information: SRF, length 8, direction 0,largest frame 4472 octets
Route Descriptors: 021C 7FFC 0220 0000 0000 0000 0000 0000

 

Target Node MAC Address 00-00-C9-0B-33-80 Stale (On Ring)

1. HaveRoute indicates the source system has a valid path to the destination system. [Return to example]

2. Information returned by the destination system in response to the route discovery process. [Return to example]

3. The LAN segments and bridges that constitute the path to the destination system. [Return to example]

4. OnRing indicates the destination system is on the same ring as the source system and does not need source routing. [Return to example]

5. Stale indicates the entry is invalid and needs to be updated by the route discovery process. [Return to example]

The following example displays all entries, with MAC addresses in noncanonical form, in the source routing table by using the shortened form of the -RTable option. The backslash (\) character is included for formatting purposes and does not appear in the actual output.

#  srconfig -rt -u

Target Node MAC Address 00:00:30:80:10:97 (ip = 130.180.4.3) Have Route
Routing Information: SRF, length 8, direction 0,largest frame 4472 octets
Route Descriptors: 021C 7FFC 0220 0000 0000 0000 0000 0000

 

Target Node MAC Address 00:00:93:08:D8:AF On Ring

 

Target Node MAC Address 10:00:D4:34:8F:9F (ip = 130.180.4.2) Stale \
 (Have Route)
Routing Information: SRF, length 8, direction 0,largest frame 4472 octets
Route Descriptors: 021C 7FFC 0220 0000 0000 0000 0000 0000

 

Target Node MAC Address 00:00:93:D0:CC:01 Stale (On Ring)

2.8    Displaying and Modifying the Token Ring IP MTU Size

By default, the DETRA adapter uses an IP maximum transfer unit (MTU) size of 4092 bytes. In a multivendor environment with different adapters using different IP MTU sizes, the bridges connecting different networks can be set up to forward smaller packet sizes. As a result, bridges might drop packets or remote hosts might reject packets. If either occurs on your network, reduce the IP MTU size for all hosts on the network and ensure that all hosts use the same size.

The following command displays the DETRA interface IP MTU size as 4092 bytes:

%  ifconfig tra0

tra0: flags=9863<UP,BROADCAST,NOTRAILERS,RUNNING>
     inet 16.141.208.3 netmask ffffff00 broadcast 16.141.208.255 ipmtu 4092

The following command changes the IP MTU size of DETRA interface to 2044 bytes:

%  ifconfig tra0 ipmtu 2044