Platform Notes: The SunATM Driver Software

ATM and Logical Interfaces

The SunATM software supports logical interfaces in the LAN Emulation environment. Logical interfaces allow you to assign multiple IP addresses to a single Emulated LAN interface. A logical interface name consists of three parts: the device name (in the case of SunATM LAN Emulation, lane); the major number, which corresponds to the lane instance number; and the minor number, which distinguishes the logical interfaces on a single physical interface. The format of a LAN Emulation logical interface name is laneN:X, where N is the major number and X is the minor number.

Each logical interface will be associated with a unique IP hostname and address. All logical interfaces on a given physical interface will be associated with the same ATM and MAC addresses. Configure logical interfaces by placing multiple entries for a given interface in the /etc/opt/SUNWconn/atm/atmconfig file.

Consider the following rules when you use logical interfaces with the SunATM software:

Only one signalling protocol (UNI 3.0, 3.1, or 4.0) is supported per interface, and must appear in the first entry for that interface.
Only one Classical IP hostname may be assigned to an interface; it can appear in any entry, in any order, in /etc/opt/SUNWconn/atm/atmconfig.
The first laneN entry on an interface must be for laneN:0, or simply laneN. laneN and laneN:0 are identical and interchangeable.
IP limits the number of logical interfaces on a physical interface to 256 (the minor number X must be in the range 0 - 255) in Solaris 2.5.1, and to 8194 (the minor number X must be in the range0 - 8193) in Solaris 2.6 and later releases.

The following examples show the atmconfig and laneconfig files and the ifconfig -a output for a system with one physical interface, ba0. That interface runs both Classical IP and LAN Emulation under UNI 3.1, and has 4 different IP addresses. Configure the hostnames, cip0, atm0, atm1, and atm2, appropriately in /etc/hosts.

The example /etc/opt/SUNWconn/atm/atmconfig file:

Interface   UNI  CIP Hostname  LANE Instance   LANE Hostname
ba0         3.1          cip0            0              atm0
ba0          -              -            0:1            atm1
ba0          -              -            0:2            atm2

The corresponding example /etc/opt/SUNWconn/atm/laneconfig file:

Interface   MAC Address/     ATM Address  VCI   Flag
            ELAN Name
lane0           -            $myaddress    -     l

The resulting ifconfig -a output:

# ifconfig -a
lo0: flags=1000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4> mtu 8232 index 1
        inet 127.0.0.1 netmask ff000000 
ba0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 9180 index 3
        inet 192.29.235.36 netmask ffffff00 broadcast 192.29.235.255
        ether 8:0:20:7a:37:af 
lane0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 4
        inet 192.29.240.36 netmask ffffff00 broadcast 192.29.240.255
        ether 8:0:20:8b:6d:d0 
lane0:1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 4        inet 192.29.241.36 netmask ffffff00 broadcast 192.29.241.255lane0:2: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 4        inet 192.29.242.36 netmask ffffff00 broadcast 192.29.242.255