Sheila
According to my reading of the Communications Server IP Configuration
Reference, the TCPCONFIG default for RESTRICTLOWPORTS or UNRESTRICTLOWPORTS
is the latter - which is as expected since this was the behaviour before
this pair of parameters was introduced. It is, in general, good practice to
specify RESTRICTLOWPORTS since this ensures that only by use of the PORT
statement (or PORTRANGE I guess but that's unlikely) can you authorise use
of a particular port in the 1 to 1023 range - under TCP - and you tie it to
a particular "job" name.
It used to be recommended that you retain all the PORT statement elements as
specified in the provided file since that way nobody could inadvertently set
up a program which used one of those ports, get away with it, maybe get it
established as a vital feature of the production environment and then you
discover later that you need it for the intended service function - all a
bit far-fetched anyhow! In case this highly unlikely scenario seemed
possible, you can now specify RESTRICTLOWPORTS, and ensure that your PORT
statement specifies only the services you actually want to run today. This
way you can get rid of all the unnecessary and unhelpful garbage in the PORT
statement list - and you can see the trees in the wood about which you
actually care!
Exactly the same - substituting UDP for TCP - can be said for the same pair
of parameters on the UDPCONFIG statement.
It is a convention for TCP and UDP that ports 1 to 1023 are assigned to
"well-known" server functions such as you will find listed in the equivalent
of what on my PC is the C\WINDOWS\system32\drivers\etc\services file.
Chris Mason
----- Original Message -----
From: "Sheila Weissborn" <[EMAIL PROTECTED]>
Newsgroups: bit.listserv.ibm-main
To: <IBM-MAIN@BAMA.UA.EDU>
Sent: Thursday, September 06, 2007 6:35 PM
Subject: Re: CA to IBM TCP Conversion
...
Speaking of port usage, here is another tip. In the TCPIP profile,
TCPCONFIG
and UDPCONFIG default to restricting usage of ports 1 through 1023. So a
port must be reserved for any application using anything in this range or
the
profile needs to have UNRESTRICTLOWPORTS coded on TCPCONFIG and
UDPCONFIG. Normally this range is used by standard applications like ftp
which are included in the sample profile.
Sheila Weissborn
Ohio Casualty Insurance
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