Classical IP Parameter Group

Classical Internet Protocol (Classical IP), specified by RFC 1577, is one way of supporting the TCP/IP and UDP/IP protocols in an ATM environment. In Classical IP, an ATM ARP server is used to resolve IP addresses to ATM addresses, replacing the traditional ARP protocol. In this configuration, each host must register with the ARP server when the ATM interface is brought up. For more information on the Classical IP protocols, see "Classical Internet Protocol".

One reason ATM ARP is used instead of the traditional ARP is that ATM does not support broadcast (a network capability providing transmission from one point to all points on a network). Because Classical IP over ATM does not support broadcast, you cannot use the ypbind -broadcast UNIX command to automatically locate the NIS server (ypserver) on a Classical IP ATM subnet.

If you are planning to run NIS over your ATM network, you must specify the list of NIS servers (ypservers) using the ypinit -c command. See the ypinit(1M) man page for details of setting up the ypserver. Be sure that the IP addresses of the ypservers are listed in the /etc/hosts file.

The Routing Information Protocol (RIP) also uses the broadcast feature of IP, so it is not supported under the Classical IP environment. In the Solaris operating environment, RIP is implemented by the daemon in.routed.

Classical IP alone also does not support the multicast packet delivery system. If you are using Classical IP, you must explicitly add the routes to the routers in the ATM subnet. You may also specify one router as the default router to provide connectivity outside of the ATM subnet. See the route(1M) man page for information on using the route command to add specific router entries and to add a default router.

You can use the Classical IP parameter group menu to define the Classical IP configuration of a SunATM interface.

Modifying ba0; Current Configuration:
    Arp Client
    IP = atm_cip
    ATM = $myaddress
    ARPSRV = $localswitch_server
        [N] No Classical IP Enabled
        [C] Client
        [S] Arp Server
        [T] Standalone
        [I] Hostname or IP Address
        [L] Local ATM Address
        [A] ATM ARP Server Address

        [P] Previous Menu
        [M] Main Menu
        [X] Exit
        [?] Help

Enter Selection:

Beginning with this release, SunATM also supports the next generation of Internet Protocol, IPv6. IPv6 ATM environments provide no support for address resolution through RFC 1577. Thus, for IPv6 environments, all destination addresses, whether PVC or SVC, must be statically configured.

Classical IP Interface Type

The SunATM software allows you to configure your interface as a Classical IP ARP server or a clien or in a standalone mode, with locally configured entriest. You can also use standalone mode to connect two systems back-to-back, using a Permanent Virtual Circuit (PVC). These three modes are options on the Classical IP parameter menu. IPv6 always operates in standalone mode.

If you are running IPv4 and IPv6 simultaneously, you cannot configure an ARP client or server for IPv4 on that Interface. It must also be configured in standalone mode

Hostname and IP Address

Regardless of the Classical IP Interface Type, you must assign an IP address and hostname to the interface. For IPv4, if you enter a hostname that appears in the /etc/hosts file, or if NIS, NIS+, or DNS is enabled and the hostname is resolvable over it, you are not prompted to enter an IP address. Instead, the resolution is performed automatically. If the hostname cannot be resolved, you are prompted to enter an IP address. If you must enter an IP address, or if the address is only available through NIS, NIS+, or DNS, the SunATM software updates the /etc/hosts file. For IPv6, you must enter the hostname in the /etc/init/ipnodes file.

A valid IP hostname is no more than 80 characters. A valid IPv4 address is a set of four decimal numbers in the range of 0 to 255, separated by dots (for example, 149.144.130.9). A valid IPv6 address is . . . . .NEED INFO.

Local ATM Address

The local ATM address is the 20-byte ATM address associated with a specific Classical IP instance. You must assign an ATM address to each Classical IP client and server, but you do not need to assign an ATM address on standalone (back-to-back) configurations. The following section describes ATM address formats and some of the SunATM software defined address variables.

ATM Address Formats and Variables

ATM addresses, like Network Service Access Point (NSAP) addresses, are 20 octets long, with each octet made up of 1 or 2 hexadecimal digits. The ATM address is divided into three fields: the End System Identifier field, the Selector field, and the Network Prefix field. The End System Identifier (ESI) field is a unique 6 octet value, which can be the IEEE hardware MAC address conventionally associated with every network interface. The Selector field is one octet long. The 13 octets that make up the rest of the ATM address are called the Network Prefix. This field should be derived from the ATM switch fabric to which the interface is connected. Every ATM switch fabric is configured with a 13 octet prefix.

To simplify references to ATM addresses in the SunATM software, several system-defined variables are built into the software. Variables are referenced with the $ operator, as in UNIX shell scripts. Table 2-3 summarizes the system-defined SunATM address variables.

The $prefix variable, and any other variables that use it (including $myaddress and $localswitch_server), can not be used on interfaces that are not running ILMI.

ATM addresses are represented by 20 colon-separated octets, with each octet made up of 1 or 2 hexadecimal digits. You can combine variables representing portions of an ATM address with other variables and/or octets to make up a complete address. For example, $prefix:aa:bb:cc:dd:ee:ff:$sel represents a valid ATM address.

ATM ARP Server Address

If you configured the Classical IP instance as a client, you must also enter the address of the ARP server. This parameter, like the local ATM address, must be a 20-byte ATM address.

Permanent Virtual Circuit (PVC)

The Permanent Virtual Circuit parameter applies only to standalone configurations, including IPv4 and IPv6. It identifies the PVC that will be used to communicate between the two systems connected either back to back or to ports on switches. Both systems must use the same PVC value. The PVC parameter must be an integer (not hexadecimal) between 32 and 1023.

Static Switched Virtual Circuit (SVC)

The ATM destination address parameter enables the Static Switched Virtual Circuit operation, which also applies only to standalone configurations, including IPv4 and IPv6. For SVC operation over IPv6 all addresses must be statically determined. This ATM destination address parameter, like the local ATM address, must be a 20-byte ATM address. See "ATM Address Formats and Variables" for more information.