Advanced TCP/IP Configuration Parameters
The following page describes advanced configuration parameters for the protocol TCP/IP section within the NET.CFG file.
During startup, TCPIP.EXE reads settings saved in the PROTOCOL TCPIP section of the NET.CFG file.Note: This file is located within the C:\REAL32\TCPIP\USRxx or C:\REAL32\TCPIP\PHAxx directory.
The parameters that can be set in the PROTOCOL TCPIP section of the NET.CFG file to configure TCPIP.EXE are summarized in the following 4 tables.
Summary of NET.CFG PROTOCOL TCPIP Board Settings
| Parameter | Values | Explanation
| BIND driver [ #board frame_type network_name ]
|
| This parameter specifies the network interface board for
the TCP/IP protocol stack. This parameter is needed only if you are
running more than one ODI driver to support TCP/IP (for example, a
workstation that uses both an Ethernet connection and a SLIP/PPP serial
link, or a network gateway machine with two network boards).
| If the PROTOCOL TCPIP section does not specify this setting, TCP/IP uses the first driver it finds in memory (the first one loaded). The #board, frame_type, and network_name values are optional. Include them only when configuring TCP/IP to run over multiple network interfaces.
| driver
| This value specifies the name of the ODI driver for this
board. For example, if the driver is NE1000.COM, the value for the
driver parameter is NE1000.
|
| #board
| This value specifies the board number bound to this
driver. This is the physical load sequence number of the board (not the
same as the logical board number displayed by the driver when it is
loaded). When this value is 0, TCP/IP binds to the first board it finds
that supports TCP/IP and also supports the specified frame_type.
|
| frame_type
| This value specifies the frame format used for this
network connection. This is the same as the frame value in the LINK
DRIVER section for this driver.
|
| network_name
| This value specifies the descriptive name for this
network connection. The network_name is used with the IP_ADDRESS,
IP_ROUTER, and IP_NETMASK parameters to distinguish between the values
for each network connection.
| |
|---|
Summary of NET.CFG PROTOCOL TCPIP Address Settings
| Parameter | Values | Explanation
| IP_ADDRESS address [ network_name ]
|
| This parameter specifies your workstation's IP address.
The value for this parameter is supplied during installation. The
IP_ADDRESSparameter has no default value.
|
| address
| This value specifies the IP address in dotted notation.
If this parameter is missing or is 0.0.0.0, the protocol stack uses
BOOTP or Reverse ARP to determine the IP address.
|
| network_name
| This value specifies the descriptive network name used in
the BIND setting or this network connection. The network_name is
required only if you are configuring multiple ODI drivers for TCP/IP.
| IP_ROUTER address [ network_name ]
|
| This parameter specifies the default router address for
an active network. TCP/IP uses the ICMP redirect mechanism to determine
all other gateways. This address is supplied during installation. The
IP_ROUTERparameter has no default value. You can specify up to three
routers for each active network.
|
| address
| This value specifies an IP address in dotted notation.
|
| network_name
| This value specifies the descriptive network name used in
the BIND setting for this network connection. The network_name is
required only if you are configuring multiple ODI drivers for TCP/IP.
| IP_NETMASK mask [ network_name ]
|
| This parameter specifies the subnetwork mask if
subnetworks are used. This parameter is supplied during installation.
The IP_NETMASKparameter has no default value.
|
| mask
| Subnetwork mask in dotted notation.
|
| network_name
| The descriptive network name used in the Bind setting for
this network connection. The network_name is required only if you are
configuring multiple ODI drivers for TCP/IP.
| |
|---|
Summary of NET.CFG PROTOCOL TCPIP Miscellaneous Settings
| Parameter | Values | Explanation
| PATH TCP_CFG [ [ drive: ] path [ ; ... ] ]
|
| This parameter specifies the directory or directories
that contain the database configuration files HOSTS, NETWORKS, PROTOCOL,
SERVICES, and RESOLV.CFG. The syntax is the same as the DOS PATH
command. The default value is \NET\TCP.
| NO_BOOTP
|
| This parameter specifies whether to bypass a BOOTP
system, if one is present on the network, and use Reverse ARP to
identify a workstation's IP address.
| The transport uses the address specified by the ip_address parameter first if this parameter is present; if not, it sends out a BOOTP request packet; and if no response is received from a BOOTP server, Reverse ARP is assumed. Including the NO_BOOTP parameter eliminates the BOOTP request packet step. TCP_WINDOW number
|
| This parameter specifies TCPIP's maximum receive window
size in bytes. You can specify a maximum value of 32,767 for number.
| TCP_MAXSEGSIZE number
|
| This parameter specifies the maximum packet segment size
you use when communicating with other nodes. You can specify a maximum
of 8192 bytes for number.
| TCP_MINRXMIT number
|
| This parameter specifies the minimum number of time-outs
that TCPIP can use. You can specify a value from 1 through 540. Each
timeout lasts 55 milliseconds.
| TCP_MAXRXMIT number
|
| This parameter specifies the maximum number of time-outs
that TCPIP can use. You can specify a value from one plus the number of
TCP_MINRXMIT time-outs through 1080 time-outs. Each time-out lasts 55
milliseconds.
| |
|---|
Summary of NET.CFG PROTOCOL TCPIP Socket Settings
| Parameter | Values | Explanation
| TCP_SOCKETS number
|
| This parameter specifies the maximum number of concurrent
TCP connections. If you configure multiple ODI drivers for TCP/ IP, the
number of TCP sockets you specify is the total shared by all drivers. | The default value is 8. The range of values is 0 through 64. UDP_SOCKETS number
|
| This parameter specifies the maximum number of concurrent
UDP connections. You should have at least one UDP socket for each
concurrently run application if you are planning to use the DNS. NetBIOS
requires at least 2 UDP sockets. If you configure multiple ODI drivers
for TCP/IP, the number of UDP sockets you specify is the total shared by
all drivers. | The default value is 8. The range of values is 0 through 32. RAW_SOCKETS number
|
| This parameter specifies the maximum number of raw IP
connections. You should have one raw IP socket if you are planning to
use the PING command or the applications that use this capability
(Serving FTPTM, IP Resolver, LWPCON). If you configure multiple ODI
drivers for TCP/IP, the number of raw sockets you specify is the total
shared by all drivers. | The default value is 1. |
|---|
Allocating Sockets
The default NET.CFG file configured by the installation program provides for eight TCP sockets, eight UDP sockets, and one raw socket. These default allocations are intended to be sufficient for most configurations. If you expect to make heavy concurrent use of applications that use sockets, you might want to modify the number of TCP sockets. You need one TCP socket for each TELNET session and two TCP sockets for each FTP session.UDP sockets are used by LWPCON and by all applications that query DNS name servers. Because UDP sockets are used briefly to send and receive datagrams, then released, you need more than the default eight UDP sockets only if you make very heavy use of DNS.
One raw socket is required for use by PING, LWPCON, and other applications
that have ping functions.
Using a BOOTP Server
If your network has a BOOTP server that is configured to supply your workstation with its IP address, router address, and subnetwork mask, omit the IP_ADDRESS, IP_ROUTER, and IP_NETMASK parameters from your NET.CFG file. If these parameters are missing, the TCP/IP Transport software expects their values to be supplied by a BOOTP server.
Using a Reverse ARP Server
The Reverse Address Resolution Protocol (RARPD) server program allows you to assign workstation IP addresses from a centrally administered IP address database on a single workstation.RARPD maintains a table in memory associating IP addresses with physical hardware (MAC) addresses of workstations on the network. A workstation configured as a RARPD client queries the RARPD server on startup, supplying its MAC address. RARPD responds with the corresponding IP address.
If your network has a reverse ARP server, such as RARPD, that provides your workstation IP address when you restart the workstation, you need to configure the following in your NET.CFG file:
 | Do not include the IP_ADDRESS parameter.
| If your network also has a BOOTP server, include the no_bootp parameter.
If this parameter is present and the ip_address parameter is absent, the
TCP/IP Transport software expects to receive the IP address from a Reverse
ARP server. | |
Setting Up NetBIOS
RFCNBIOS.EXE implements the NetBIOS B-node protocols as defined in RFCs 1001 and 1002. (The B-node protocols use broadcast datagrams for network management and some NetBIOS datagram operations.) With this software, you can run any workstation network application designed for the standard NetBIOS interface.IMPORTANT: All directly connected NetBIOS nodes with which you plan to communicate must use an RFC1001/1002-compliant NetBIOS program. Also, all NetBIOS implementations must be B-node configurations.
The NetBIOS software is customized in the PROTOCOL TCPIP and PROTOCOL RFCNBIOS sections of the NET.CFG file. The following 2 tables summarize the NetBIOS settings.
Summary of NetBIOS NET.CFG Protocol TCPIP Section Settings
| Parameter | Explanation
| NB_SESSIONS number
| This parameter specifies the maximum number of concurrent
NetBIOS sessions. When you specify this setting, you must increase the
number of TCP sockets you allocate (TCP_SOCKETS setting) to at least 1
plus the value of this setting. | The default value of number is 4. You can specify a setting from 0 through 64. NB_COMMANDS number
| This parameter specifies the maximum number of
asynchronous NetBIOS commands. | The default value of number is 20. You can specify a setting from 0 through 80. NB_DOMAIN domain_name
| This parameter specifies the name of the logical domain
for this NetBIOS station. The value of this setting is an ASCII string.
By default the value of domain_name is null.
| NB_ADAPTER { 0 | 1 }
| This parameter specifies which NetBIOS board to use.
| NB_BRDCAST { 0 | 1 | IP_address}
| This parameter specifies the format of IP broadcasts used
when RFCNBIOS.EXE sends broadcast messages.
| The value 0 sets the broadcast address to use zeroes for the host portions of the IP address. For example, a Class B network with network address 122.44 would have broadcast address 122.44.0.0. The value 1 sets the broadcast address to use 255 for the host portions of the IP address. For example, a Class B network with network address 122.44 would have broadcast address 122.44.255.255. |
|---|
Summary of NetBIOS NET.CFG Protocol RFCNBIOS Section Settings
| Parameter | Explanation
| REMOTENAMEn IP_address
| This parameter specifies an IP address on a different
broadcast network from the workstation. This address is preloaded in the
NetBIOS name cache. The value of n can be from 1 through 16.
| |
|---|
The following information describes the configuration of the NetBIOS settings
in the NET.CFG file.
NB_ADAPTER { 0 | 1 }
This parameter specifies which NetBIOS adapter number to bind to TCP/IP. This value must be either 0 or 1 (the first network board is 0, the second is 1).You can specify this setting using NB_ADAPTER in the following format:
NB_ADAPTER { 0 | 1 }
For example:
PROTOCOL TCPIP IP_ADDRESS 129.47.6.84 . . NB_ADAPTER 0
The default value for this setting is 0.
NB_BRDCAST { 0 | 1 } IP_address
This parameter specifies the format of IP broadcasts used when RFCNBIOS.EXE sends broadcast messages.The value 0 sets the broadcast address to use zeroes for the host portions of the IP address. Therefore, a Class B network with a network address of 129.47 would have a broadcast address of 129.47.0.0.
The value 1 sets the broadcast address to use 255 for the host portions of the IP address. Therefore, a Class B network with a network address of 129.47 would have a broadcast address of 129.47.255.255.
You can specify this setting using NB_BRDCAST in the following format:
NB_BRDCAST { 0 | 1 }
For example:
PROTOCOL TCPIP IP_ADDRESS 129.47.6.84 . . NB_BRDCAST 0
The default value is 1.
NB_COMMANDS number
This parameter specifies the maximum number of asynchronous NetBIOS commands. Each pending NetBIOS command requires 32 bytes of memory.You can specify this setting using NB_COMMANDS in the following format:
NB_COMMANDS number
For example:
PROTOCOL TCPIP IP_ADDRESS 129.47.6.84 . . NB_COMMANDS 16
You can specify a value from 0 through 80 for number. By default, number has
the value of 8.
NB_DOMAIN domain_name
This parameter specifies the name of the logical domain for this NetBIOS station. All stations in the same logical domain must use the same value for NB_DOMAIN.You can specify this setting using NB_DOMAIN in the following format:
NB_DOMAIN domain_name
For example:
PROTOCOL TCPIP IP_ADDRESS 129.47.6.84 . . NB_DOMAIN BIOSPHERE_2
You can specify a string with up to 80 characters for domain_name. By
default, domain_name has a null value.
NB_SESSIONS Number
This parameter specifies the maximum number of concurrent NetBIOS sessions. Your TCP_SOCKETS setting must be at least 1 plus the number of sessions you specify with the NB_SESSIONS setting. You can specify a number from 0 through 64.You can specify this setting using NB_SESSIONS in the following format:
NB_SESSIONS number
For example:
PROTOCOL TCPIP BIND NE1000 IP_ADDRESS 129.47.6.84 . . NB_SESSIONS 8
The default value for number is 4.
REMOTENAMEn IP_address
This parameter is included in the PROTOCOL RFCNBIOS section of the NET.CFG file. It specifies an IP address that is not on the same broadcast network as your workstation. This address is preloaded in the NetBIOS name cache.You can specify the IP address with REMOTENAME in the following format:
REMOTENAMEn IP_address
Where n is the number you assign to an IP address, and IP_address is the IP address in decimal notation.
For example:
PROTOCOL RFCNBIOS REMOTENAME1 129.57.52.6 REMOTENAME2 129.57.32.8
You can specify up to 16 remote names with this parameter.