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Forcing named 9 to use a fixed ephemeral port range

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Operating Systems AIX Forcing named 9 to use a fixed ephemeral port range
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Old 02-02-2018
Forcing named 9 to use a fixed ephemeral port range
I'll start with I'm not an AIX expert, I inherited a lot of AIX servers to maintain.

My problem is on AIX 7.1 TL4 SP4 environments. I'm running named as a DNS forwarder only to internal DNS servers.

These AIX servers have a customized UDP ephemeral port range to avoid conflicting with the primary application running on them that defaults to a portion of the typical ephemeral range.

Since configuring named, I've seen that named is ignoring the OS configured ephemeral range.

The OS restricted UDP range is: 32768 to 49999.
I've seen requests from named using source ports above 49999.

After googling, the only article I can find that references named/bind and ephemeral ports is a page from ISC related to BIND 9. There's a setting "use-v4-udp-ports { range 1024 65535; };" that forces named to use a fixed UDP range for source ports. But the IBM documentation on named doesn't cover this option.
I tried putting the setting onto named.conf on a test system but now named won't start and no errors are logged.
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LEARN ABOUT DEBIAN

lsdistcc

lsdistcc(1)						      General Commands Manual						       lsdistcc(1)

NAME

       lsdistcc - simple distcc server discovery

SYNOPSIS

       lsdistcc [OPTIONS] [FORMAT]

       lsdistcc [OPTIONS] host1 ...

DESCRIPTION

       lsdistcc autodetects listening distcc servers either by looking in DNS for hosts named according to a given FORMAT, or by checking the host
       names given on the command line.

       Hosts are considered good servers based solely on whether their name fits the format and whether they are listening on the right port  (and
       optionally whether they respond when you send them a compile job).

       Scans  for  hosts  named according to FORMAT (default is "distcc%d"; see printf(3)) and starting from 1, so hosts such as distcc1, distcc2,
       and so on.  Stops after 7 seconds or the first host name that does not resolve.	Prints the names of all such servers listening on distcc's
       port.

       If a list of host names is given in the command line, lsdistcc will only check those hosts.

OPTIONS

       --help Displays summary instructions

       -l     Output latency in milliseconds after each hostname (not including DNS latency)

       -n     Print IP address rather than name

       -x     Append ,down to down hosts in host list

       -tTIMEOUT
	      Set number of seconds to stop searching after [7]

       -hHTIMEOUT
	      Set number of milliseconds before retrying gethostbyname [500]

       -cCTIMEOUT
	      Set number of milliseconds before giving up on connect [900] (0 to inhibit connect)

       -kKTIMEOUT
	      Set number of milliseconds before giving up on compile [1500] (0 to inhibit compile)

       -mBITS Set number of bits of address that must match first host found [0]

       -oOVERLAP
	      Set number of extra DNS requests to send [1]

       -gDNSGAP
	      Set number of missing DNS entries to tolerate [0]

       -rPORT Port to connect to [3632]

       -PPROTOCOL
	      Protocol version to use (1-3) [1]

       -pCOMPILER
	      Name of compiler to use [none]

       -d     Append DNS domain name to format

       -v     Verbose

EXAMPLES

       Scan for servers named distcc1, distcc2, ...  that provide a compiler named gcc-4.6 and include their latencies in the output:

	      $ lsdistcc -l -pgcc-4.6

       Scan for a compiler named gcc-4.6 on the servers hosta, somehost, hostx, and hosty:

	      $ lsdistcc -pgcc-4.6 hosta somehost hostx hosty

       To use the program in a build script, add the lines:

	      DISTCC_HOSTS=`lsdistcc`
	      export DISTCC_HOSTS

       before the line that invokes make.  Or, in a Makefile, add the line:

	      export DISTCC_HOSTS = $(shell lsdistcc)

EXIT STATUS

       The exit status is 0 if any servers were found, and 1 otherwise.

       Uses  'for i=1... sprintf(format, i)' to construct names of servers, stops after 7 seconds or at second server that doesn't resolve, prints
       the names of all such servers listening on distcc's port.  Default format is distcc%d.

SEE ALSO

       distcc(1), distccd(1), printf(3)

       http://code.google.com/p/distcc/

AUTHOR

       lsdistcc was written by Dan Kegel, Dongmin Zhang, and Manos Renieris.

       This manual page was written by Daniel Hartwig for the Debian project.

								    1 May 2012							       lsdistcc(1)