Basic ATM Interface Plumbing

ATM interfaces must be plumbed prior to configuration for LANE or Classical IP. This plumbing configuration is specified in the /etc/opt/SUNWconn/atm/atmconfig file. For a detailed description of plumbing and unplumbing ATM interfaces, see "Plumbing and Unplumbing Individual ATM Interfaces".

Editing the /etc/opt/SUNWconn/atm/atmconfig File

The /etc/opt/SUNWconn/atm/atmconfig file is a generic file that must appear on every SunATM system. It provides general configuration information used by the SunATM setup utilities to bring up ATM interfaces at boot time.

The file consists of one or more entries per interface. An entry contains the following fields described in Table 3-1:

The Interface and UNI fields are required for all interfaces. The CIP_Host field is required for interfaces that run Classical IP, and the LANE_Instance and LANE_Host fields are required for interfaces that run LAN Emulation. If a field is not used, it is represented by a hyphen.

Modifications to individual interfaces will take effect when the interface is plumbed. This will happen either at boot time or when you use the atmifconfig utility to plumb interfaces. If you modify an existing (already running) interface, you must first unplumb it with the atmifconfig utility. Refer to the atmifconfig(1m) man page or "Plumbing and Unplumbing Individual ATM Interfaces" for more information.

Changing the Framing Interface in the /etc/opt/SUNWconn/atm/atmconfig File

The framing interface defines the encapsulation method used for ATM cells as they are sent onto the wire. The default framing interface is SONET, but the SunATM software also supports the SDH interface. Your switch product information should indicate which interface your switch uses.

Previous versions of the SunATM software allowed you to choose a framing interface for the entire system (by setting a variable in the /etc/system file). In the SunATM software, the system variable can be used to allow backwards compatibility, but the preferred method is to select the framing interface for each interface and to add an entry in the /etc/opt/SUNWconn/atm/atmconfig file. An entry in /etc/opt/SUNWconn/atm/atmconfig overrides a variable set in /etc/system for a particular interface. If there is no value in either /etc/system or /etc/opt/SUNWconn/atm/atmconfig, the default framing interface is SONET.

Framing entries in /etc/opt/SUNWconn/atm/atmconfig should appear on individual lines, with two fields. The first field indicates the interface, baN, where N is the instance number (for example: ba0). The second is either SDH or SONET, depending on the desired setting.

Example of an /etc/opt/SUNWconn/atm/atmconfig File

The following sample atmconfig file creates this configuration:

• A LAN Emulation interface lane0, supporting UNI 3.1, on the ba0 interface.

• An interface that supports both Classical IP and LAN Emulation on ba1, using UNI 4.0. The LAN Emulation interface name is lane1.

• A Classical IP interface, supporting UNI 3.0, on ba2, which uses the SDH framing interface.

  #Interface UNI/Framing CIP_Host LANE_Instance LANE_Host #-------------------------------------------------------------- ba0 3.1 - 0 atm0 ba1 4.0 atm1 1 atm2 ba2 3.0 atm3 - - ba2 SDH

Using Variables in the  /etc/opt/SUNWconn/atm/aarconfig File

Because the prefix portion of an ATM address specifies the ATM switch, a number of hosts specified in an aarconfig file can have ATM addresses that share the same prefix. To simplify setting up the aarconfig file, you can define variables that contain part of an ATM address.

A variable's name is an identifier consisting of a collection of no more than 32 letters, digits, and underscores. The value associated with the variable is denoted by a dollar sign followed immediately by the variable name.

Use variables in the ATM address field only. They are not valid in any of the other fields in an entry.

You can use a colon to concatenate multiple variables to represent a single ATM address expression. Thus, if one variable, v1, is set to 11:22 and another variable, v2, is set to 33:44, the sequence $v1:$v2 represents 11:22:33:44. You can include hexadecimal numbers with variables in the expression. The expression 45:$v1:$v2 would have the value 45:11:22:33:44.

Use the following format to define variables in the aarconfig file:

set VARIABLE = EXPRESSION

where VARIABLE is the name of a variable and EXPRESSION is an expression concatenating one or two-digit hexadecimal numbers or the values of variables that have been previously defined. The equal sign is optional, but separate the variable and expression either by white space (spaces or tabs), an equal sign, or both.

Several predefined variables are built into the SunATM software. These variables are summarized in Table 3-2.

You can not use the $prefix variable or any other variables that use it (including $myaddress and $localswitch_server) on interfaces that are not running ILMI.

In most network configurations, the ATM address assigned to the local interface is $myaddress; using this variable in the l entry makes it possible to use identical aarconfig files on all Classical IP clients using a given server.

The sunmacselN variables can be used in conjunction with a prefix, as well as with known server addresses that are not bound to a particular system. As an example, consider the case where a server that supports 50 clients fails. If the ATM address of the server is specific to that particular server, you must change the s entry on all 50 clients to switch to a backup server. However, if the ATM address used for that server is $prefix:$sunmacsel3, this address is not only guaranteed to be unique, since it uses reserved medium access control (MAC) addresses, you can also simply assign that address to the backup server on the same switch by changing the l entry to an s entry on one system and bringing up a new server with no changes to the clients.

The sunmacselN variables do not include a prefix since a client and server may be on different switches and thus have different local prefix values.

In the case of a single-switch network, you can use localswitch_server as a well-known server address that includes the prefix associated with the local switch and a MAC address. It will restrict server access to clients on the local switch and provide a unique ATM address among all ATM clients connected to that switch. Thus, any host with a network prefix other than that of the local switch will be refused a connection to the ARP server if the ARP server's address is $localswitch_server.

Several rules apply to the use of variables in the aarconfig file:

• Two variables cannot follow each other in an expression without an intervening colon. Thus $v1:$v2 is legal while $v1$v2 is not.

• Fields in each line in the aarconfig file are separated by white space. Therefore, variables should not be separated from the rest of an ATM address with white space. For example, $v1: $v2 is illegal.

• Once a variable is defined by a set command, it may not be redefined later in the same configuration file.

• The reserved variable names cannot be set. These names include prefix, mac, sel, macsel, myaddress, anymac, anymacsel, sunmacselN (where N is a number between 0 and 199), and localswitch_server.

  ---

  Note -

  The ESI portion of localswitch_server and the sunmacselN variables is a reserved MAC address. The hexadecimal values of the reserved addresses are: localswitch_server 08:00:20:75:48:08 sunmacselN base 08:00:20:75:48:10 To calculate the ESI portion for a sunmacselN address, simply add the value of N (converted to a hexadecimal number) to the sunmacselN base address. For example, the ESI portion of sunmacsel20 would be 08:00:20:75:48:10 + 0x14 = 08:00:20:75:48:24.

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Sample Classical IP Configurations

The following examples demonstrate entries in the /etc/opt/SUNWconn/atm/aarconfig file for several typical network configurations.

Although some of the examples show only one sample aarconfig file, similarly configured files must appear on each system. Example 2 shows the files for each of the three systems in the configuration.

1. SVC-only: Clients use the default address and access to the ARP server is restricted to clients on the local switch only.

   1. The /etc/opt/SUNWconn/atm/aarconfig file on a client:

      Interface Host ATM Address VCI Flag ba0 - $myaddress - l ba0 - $localswitch_server - s

   2. The /etc/opt/SUNWconn/atm/aarconfig file on the server:

      Interface Host ATM Address VCI  Flag ba0 - $localswitch_server -    L

2. PVC-only: hosta is connected to hostb and hostc over PVCs. There is no ARP server.

   1. /etc/opt/SUNWconn/atm/aarconfig on hosta:

      Interface Host      ATM Address VCI Flag ba0         -   -      - l ba0 hostb -     100     t ba0 hostc -     101     t

   2. on hostb:

      Interface     Host    ATM Address      VCI  Flag ba0 -         - -       l ba0  hosta         -        100       t ba0   hostc        -        102       t

   3. on hostc:

      Interface Host ATM Address VCI Flag ba0        -      -                -      l ba0        hosta  -              101      t ba0        hostb  -              102      t

3. SVC with no ARP server: hosta uses SVCs to connect to hostb and hostc. All hosts are connected to the same switch; there is no ARP server.

   Interface   Host   ATM Address VCI Flag ba0 - $myaddress                       - l ba0 hostb $prefix:08:00:20:d5:08:a8:00     - t ba0 hostc $prefix:08:00:20:21:20:c3:00     -     t

4. PVC/SVC mix: hosta uses an SVC to connect to hostb, and a PVC to connect to hostc. hostb is not on the local switch; there is no ARP server.

   Interface  Host  ATM Address                                           VCI  Flag ba0        -     $myaddress -     l ba0       hostb 45:00:00:00:00:00:00:00:0f:00:0:08:00:20:d5:08:a8:00   -     t ba0       hostc  -                                                       100   t

5. IPv6 PVC/SVC mix: hosta uses an SVC to connect to hostb, and a PVC to connect to hostc.

   Interface Host ATM Address VCI Flagba0 - $myaddress - lba0 hostb-v6 $prefix:08:00:20:d5:08:a8:00 - t6ba0 hostc-v6 - 100 t6

6. IPv4/IPv6 mix: hosta uses a static IPv4 SVC to connect to hostb and a static IPv6 SVC to connect to hostc.

   Interface Host ATM Address VCI Flagba0 - $myaddress - lba0 hostb $prefix:08:00:20:d5:08:a8:00 - tba0 hostc-v6 $prefix:08:00:20:21:20:c3:00 - t6

7. ARP server with Access Restrictions: Hosts are connected to an ATM ARP server that resolves addresses. Access is restricted to the local switch subnet and one additional switch subnet.

   1. /etc/opt/SUNWconn/atm/aarconfig on hosta:

      Interface     Host     ATM Address          VCI           Flag ba0           -        $myaddress             -              l ba0           -        $prefix:$sunmacsel0    -              s

   2. /etc/opt/SUNWconn/atm/aarconfig on server:

      Interface Host ATM Address      VCI    Flag ba0 - $prefix:$sunmacsel0       -       L ba0 - $prefix:$anymacsel       -       a ba0         - 45:00:00:00:00:00:00:00:0f:00:00:00:00:$anymacsel   -       a

8. Manual address configuration: Hosts are connected to a switch that does not support ILMI.

   1. /etc/opt/SUNWconn/atm/aarconfig on server:

      set prfx = 45:00:00:00:00:00:00:00:0f:00:00:00:00 Interface  Host  ATM Address        VCI        Flag ba0        -     $prfx:$sunmacsel0    -           L ba0        -     -                    -           m

   2. /etc/opt/SUNWconn/atm/aarconfig on client:

      set prfx = 45:00:00:00:00:00:00:00:0f:00:00:00:00 Interface  Host  ATM Address        VCI         Flag ba0        -     $prfx:$macsel        -            l ba0        -     $prfx:$sunmacsel0    -            s ba0        -      -                   -            m