Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1: Base Functions, Connectivity, and Routing

72 Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1 - Base Functions, Connectivity, and Routing

PROFILE.TCPIP

Before you start your TCP/IP stack, you must configure the operational and address space

characteristics.

These definitions are entered into a PROFILE configuration data set that is read by the

TCP/IP address space during initialization.

A sample PROFILE.TCPIP configuration file is provided in hlq.SEZAINST(SAMPPROF).

The PROFILE data set contains the following major groups of TCP/IP configuration

parameters:

򐂰 Operating characteristics

򐂰 Reserved port number definitions

򐂰 Network connectivity definitions

򐂰 Telnet definitions

򐂰 Network routing definitions

For more information about TCP/IP Telnet definitions, see Communications Server for z/OS

V1R7 TCP/IP Implementation, Volume 2 - Standard Applications, SG24-7170.

Detailed information about TCP/IP connectivity and routing definitions can be found in

Chapter 4, “Connectivity” on page 101, and Chapter 5, “Routing” on page 139, respectively.

3.6.2 VTAM Resource

As mentioned in the introduction, VTAM provides the Data Link Control layer (Layer 2 of the

OSI model) for TCP/IP, including support of the Multi-Path Channel (MPC) interfaces. MPC

protocols are used to define the DLC layer for OSA-Express devices in QDIO. OSA-Express

QDIO connections are configured via a TRLE definition. All TRLEs are defined as VTAM

major nodes. For further information about MPC-related devices/interfaces refer to Chapter 4,

“Connectivity” on page 101.

A TRLE definition we used for our OSA-Express in QDIO mode is shown in Example 3-3.

Example 3-3 TRLE VTAM major node definition for device OSA2080

OSA2080 VBUILD TYPE=TRL

OSA2080P TRLE LNCTL=MPC,

READ=2080,

WRITE=2081,

DATAPATH=(2082-2087),

PORTNAME=OSA2080, 1

MPCLEVEL=QDIO

SInce VTAM provides the DLC layer for TCP/IP, then VTAM must be started before TCP/IP.

The major node (in our case, OSA2080) should be activated when VTAM is initializing. This

will ensure the TRLE is active when the TCP/IP stack is started. This is accomplished by

placing an entry for OSA2080 in the VTAM startup list ATCCONxx. The portname 1

(Example 3-3) must also be the same name as the device name defined in TCP/IP PROFILE

data set on the DEVICE and LINK statements.

3.6.3 PROFILE.TCPIP parameters

The syntax for the parameters in the PROFILE can be found in z/OS V1R7.0 CS: IP

Configuration Reference, SC31-8776.

Chapter 3. Base functions 73

Most PROFILE parameters required in a basic configuration have default values that will

allow the stack to be initialized and ready for operation. There are, however, a few

parameters that must be modified or must be unique to the stack.

AUTOLOG considerations

The purpose of the AUTOLOG statement is to start all procedures specified. AUTOLOG also

monitors procedures started under its auspices, and will restart a procedure that terminates

for any reason unless NOAUTOLOG is specified on the PORT statement.

For UNIX servers some special rules apply. If the procedure name on the AUTOLOG

statement is eight characters long, no jobname needs be specified. If the procedure name on

the AUTOLOG statement is less than eight characters long and the job spawns listener

threads with different names, you may have to specify the JOBNAME parameter and ensure

that the jobname matches that coded on the PORT statement. In the following example,

jobname FTPDE1 on the PORT statement matches JOBNAME on the AUTOLOG statement:

PORT

20 TCP OMVS

21 TCP FTPDE1

AUTOLOG 1

FTPDE1 JOBNAME FTPDE1 ; FTP Server

ENDAUTOLOG

HOME

The TCP/IP stack uses an IP address of 127.0.0.1 for IPv4 and ::1 for Pv6 as the loopback

interfaces. If there is a requirement to represent the loopback IP address of 14.0.0.0 for

compatibility with earlier TCP/IP versions, you must code an entry in the HOME statement.

The link label specified is LOOPBACK and you can define multiple IP addresses with the

LOOPBACK interface. For example:

HOME

14.0.0.0 LOOPBACK

The onetstat -h command displays the home address assignments of the currently running

stack. The display results are similar to the NETSTAT HOME command in TSO and the z/OS

command D TCPIP,procname,NETSTAT,HOME. There is an additional field, called the Flg

field, that indicates which interface is the primary interface. The primary interface is the

address that is inserted as the source address in an IP header when communicating to a

destination through an indirect route. The primary interface is the first entry in the HOME list

in the PROFILE.TCPIP definitions unless the PRIMARYINTERFACE parameter is specified.

Example 3-4 Netstat home display

D TCPIP,TCPIPE,N,HOME

EZD0101I NETSTAT CS V1R7 TCPIPE 751

HOME ADDRESS LIST:

LINKNAME: STAVIPA1LNK

ADDRESS: 10.10.10.210

FLAGS: PRIMARY

LINKNAME: OSA2080LNK

ADDRESS: 10.10.2.212

FLAGS:

LINKNAME: OSA20A0LNK

ADDRESS: 10.10.3.213

FLAGS:

LINKNAME: OSA20C0LNK

ADDRESS: 10.10.2.214

FLAGS: