From 607166118cba9a8b35df63aadcba796c2ee7d3e8 Mon Sep 17 00:00:00 2001 From: Jeff Hill Date: Wed, 5 Jan 2000 17:34:49 +0000 Subject: [PATCH] doc upgrade --- configure/CONFIG_ENV | 178 +++++++++++++++++++++++++------------------ 1 file changed, 103 insertions(+), 75 deletions(-) diff --git a/configure/CONFIG_ENV b/configure/CONFIG_ENV index 5d4a3c005..7b3d28cf5 100644 --- a/configure/CONFIG_ENV +++ b/configure/CONFIG_ENV @@ -1,10 +1,10 @@ -# $Id$ -# Author: Andrew Johnson -# Date: 20 April 1995 +# $Id$ +# Author: Andrew Johnson +# Date: 20 April 1995 # -# Experimental Physics and Industrial Control System (EPICS) +# Experimental Physics and Industrial Control System (EPICS) # -# CONFIG_ENV - EPICS Environment Parameter configuration file +# CONFIG_ENV - EPICS Environment Parameter configuration file # # This file is interpreted by the Bourne Shell, so spaces are # not allowed around the '=' signs or in unquoted values. @@ -12,7 +12,7 @@ # # Note: This file is read by base/src/libCom/bldEnvdata.pl, # so the variable definitions in here should be kept 'simple': -# VAR=VALUE +# VAR=VALUE # each one on a single line. # @@ -21,17 +21,17 @@ # Channel Access: # EPICS_CA_ADDR_LIST -# Augment beacon/search dest ip addr list -# from white space separated ip addresses in this -# environment variable. "Quote" if more than one addr. +# Augment beacon/search dest ip addr list +# from white space separated ip addresses in this +# environment variable. "Quote" if more than one addr. # EPICS_CA_AUTO_ADDR_LIST -# YES = augment beacon/search dest ip -# addr list from network interfaces found; NO = only use -# EPICS_CA_ADDR_LIST to create this list. +# YES = augment beacon/search dest ip +# addr list from network interfaces found; NO = only use +# EPICS_CA_ADDR_LIST to create this list. # EPICS_CA_CONN_TMO -# after not seeing a server beacon for this number -# of seconds the clients will send an echo request over -# tcp/ip to verify the connection. +# after not seeing a server beacon for this number +# of seconds the clients will send an echo request over +# tcp/ip to verify the connection. # EPICS_CA_REPEATER_PORT CA repeater port number. # EPICS_CA_SERVER_PORT CA server port number. @@ -45,69 +45,97 @@ EPICS_CA_SERVER_PORT=5064 # These parameters are only used by the CA server library # # EPICS_CA_BEACON_PERIOD -# quiescent sec between server beacons. -# EPICS_CAS_INTF_ADDR_LIST - list of IP addresses identifying -# a limited set of network interfaces for server communication. -# Specifically, this parameter specifies the interfaces from -# which the server will accept TCP/IP connections. It also -# specifies that UDP search messages addressed to both -# the IP addresses in EPICS_CAS_INTF_ADDR_LIST and also -# the broadcast addresses (or the destination addresses of -# point to point interfaces) of the corresponding interfaces -# will be accepted by the server. If this parameter is empty -# then TCP/IP connections are accepted from any interface -# (and any search messages addressed to the host are accepted). -# Beacons are sent only to the broadcast address of each interface -# in this list (or the destination address of point to point -# interfaces) if EPICS_CA_AUTO_ADDR_LIST is YES. -# Type "ifconfig -a" in order to determine which interfaces -# are available. -# EPICS_CAS_BEACON_ADDR_LIST - If this parameter is specified -# or if EPICS_CAS_INTF_ADDR_LIST isnt empty then this parameter -# is used instead of EPICS_CA_ADDR_LIST by the server library -# to augment the list of addresses to send beacons to. -# EPICS_CAS_SERVER_PORT - If this parameter is specified then it -# and not EPICS_CA_SERVER_PORT is used to determine the server's -# port number. It is possible to have multiple servers on the -# same host on the same EPICS_CAS_SERVER_PORT port if the IP -# kernel is modern (if it has multicast enhancements). In this -# situation all servers will share the same user specified -# UDP port number and will be assigned unique TCP port numbers. -# The fact that the servers may not be using the user specified -# port number for TCP will be completely transparent to EPICS -# 3.13 or higher clients that will be locating the servers -# using the user specified UDP port number, but will be connecting to -# the servers using whatever TCP port has been assigned. +# The quiescent sec between server beacons. +# +# EPICS_CAS_INTF_ADDR_LIST +# This specifies a list of IP addresses identifying +# a limited set of network interfaces for server communication. +# +# Specifically, this parameter specifies the interfaces from +# which the server will accept TCP/IP connections. It also +# specifies that UDP search messages addressed to both +# the IP addresses in EPICS_CAS_INTF_ADDR_LIST and also to +# the broadcast addresses of corresponding LAN interfaces +# will be accepted by the server. If this parameter is empty +# then all UDP search messages and TCP connection requests +# addressed to the host are accepted. +# +# If EPICS_CA_AUTO_ADDR_LIST is NO, then the beacon address list +# is not auto configured. +# +# If EPICS_CA_AUTO_ADDR_LIST is YES and EPICS_CA_AUTO_ADDR_LIST +# has _not_ been specified then beacons are sent to the broadcast +# addresses of all LAN interfaces and the destination addresses of +# all point-to-point serial interfaces. +# +# If EPICS_CA_AUTO_ADDR_LIST is YES and EPICS_CA_AUTO_ADDR_LIST +# has been specified then beacons are sent to the broadcast address +# of each LAN interface corresponding to an IP address in +# EPICS_CA_AUTO_ADDR_LIST or the destination address of +# a point-to-point serial interfaces corresponding to an IP +# address in EPICS_CA_AUTO_ADDR_LIST. +# +# Beacons may be sent to additional hand configured addresses +# (see the notes below under EPICS_CAS_BEACON_ADDR_LIST). +# +# EPICS_CAS_BEACON_ADDR_LIST +# If this parameter is specified, or if EPICS_CAS_INTF_ADDR_LIST +# isnt empty, then this parameter is used by the server library to +# augment the list of addresses beacons are sent to. Otherwise +# EPICS_CA_ADDR_LIST is used to augment the list of addresses +# beacons are sent to. +# +# EPICS_CAS_SERVER_PORT +# If this parameter is specified then it +# and not EPICS_CA_SERVER_PORT is used to determine the server's +# port number. It is possible to have multiple servers on the +# same host on the same EPICS_CAS_SERVER_PORT port if the IP +# kernel is modern (if it has multicast enhancements). In this +# situation all servers will share the same user specified +# UDP port number and will be assigned unique TCP port numbers. +# +# The fact that the servers may not be using the user specified +# port number for TCP will be nearly transparent to EPICS +# 3.13 or higher clients that will be locating the servers +# using the user specified UDP port number, but will be connecting to +# the servers using whatever TCP port has been assigned. +# Unfortunately, a severe limitation exists in most IP +# kernels: if multiple servers are listening for search requests +# addressed to the same UDP port then they will all receive a copy +# of each UDP message received by the IP kernel that has a broadcast +# destination address. Unfortunately, in many IP kernel +# implementations only one of the servers will receive UDP +# messages with a single host (unicast) destination address. # # If experiencing trouble getting clients to connect -# -------------------------------------------------- +# -------------------------------------------------- # -# o Make sure that the broadcast addresses are identical on the -# server's host and on the client's host. This can be checked with -# "netstat -i" or "ifconfig -a". -# -# o Make sure that the client and server are using the same UDP -# port. Check the server's port by running "netstat -a | grep nnn" -# where nnn is the port number involved. If you do not set -# EPICS_CA_SERVER_PORT or EPICS_CAS_SERVER_PORT -# then the default port will be 5064. -# -# o Two servers can run on the same host with the same server port number -# if the following restrictions are understood (good luck). If the host has a -# modern IP kernel it is possible to have two servers on the same UDP port. -# It is not possible for two servers to run on the same host using the same -# TCP IP server port. If the CA server library detects that a 2nd server is attempting -# to start on the same port as an existing CA server then both servers will use the -# same UDP port if it is a modern IP kernel, and the 2nd server will -# be allocated a new TCP port. In this situation the clients will still be -# configured to use the same port number for both servers. The clients -# will find the 2nd server via the shared UDP port, and transparently -# connect to the 2nd server's allocated TCP port. Be aware that If there are -# two server's running on the same host on the same UDP port then they will -# both receive all UDP search requests sent as broadcasts, but will unfortunately (due to -# what I consider to be a real weakness of most IP kernel implementations) only one -# of the servers will typically receive UDP search requests sent to unicast addresses (i.e. -# a specific host's ip address). +# o Make sure that the broadcast addresses are identical on the +# server's host and on the client's host. This can be checked with +# "netstat -i" or "ifconfig -a". +# +# o Make sure that the client and server are using the same UDP +# port. Check the server's port by running "netstat -a | grep nnn" +# where nnn is the port number involved. If you do not set +# EPICS_CA_SERVER_PORT or EPICS_CAS_SERVER_PORT +# then the default port will be 5064. +# +# o Two servers can run on the same host with the same server port number +# if the following restrictions are understood (good luck). If the host has a +# modern IP kernel it is possible to have two servers on the same UDP port. +# It is not possible for two servers to run on the same host using the same +# TCP IP server port. If the CA server library detects that a 2nd server is attempting +# to start on the same port as an existing CA server then both servers will use the +# same UDP port if it is a modern IP kernel, and the 2nd server will +# be allocated a new TCP port. In this situation the clients will still be +# configured to use the same port number for both servers. The clients +# will find the 2nd server via the shared UDP port, and transparently +# connect to the 2nd server's allocated TCP port. Be aware that If there are +# two server's running on the same host on the same UDP port then they will +# both receive all UDP search requests sent as broadcasts, but will unfortunately (due to +# what I consider to be a real weakness of most IP kernel implementations) only one +# of the servers will typically receive UDP search requests sent to unicast addresses (i.e. +# a specific host's ip address). #