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MRTG-IPV6(1)			     mrtg			  MRTG-IPV6(1)

NAME
       mrtg-ipv6 - IPv6	support	in MRTG

OVERVIEW
       MRTG and	cfgmaker support SNMP over IPv6. IPv6 targets can be specified
       by hostname or IPv6 address, and	if the required	libraries are present
       (see below), queries will use IPv6.

USAGE
   Enabling IPv6
       IPv6 is currently disabled by default and must be explicitly enabled.
       In MRTG this is done by turning on the EnableIPv6 global	option in the
       configuration file. In cfgmaker,	it is enabled with the --enable-ipv6
       command-line option.

       If IPv6 is disabled, MRTG and cfgmaker should behave in exactly the
       same way	as previous versions. So the addition of IPv6 support should
       have no effect on existing MRTG setups unless IPv6 is enabled.

       IPv6 support requires the Socket6 and INET6 libraries (see below). If
       MRTG can't find them, IPv6 is disabled.

   Specifying IPv6 targets
       IPv6 targets may	be specified by	name or	IPv6 address. Numeric IPv6
       addresses may be	used with both cfgmaker	and MRTG, but they must	be
       enclosed	in square brackets.

       For example, a target could be specified	as:

	public@[2001:760:4::]:161

       Hostnames work as expected: first an IPv6 name lookup is	tried, then an
       IPv4 lookup.

   Targets that	do not support SNMP over IPv6
       Many targets (this currently includes all Cisco routers)	do not yet
       support SNMP over IPv6 and must be monitored over IPv4. This can	cause
       problems	if you specify a target	through	its DNS	name and the name maps
       to both the IPv6	address	and the	IPv4 address of	the target: MRTG will
       only try	IPv6, and will fail.

       To query	these targets, use the IPv4Only	per-target option, which tells
       MRTG not	to use SNMP over IPv6 for the target.

       MRTG does not fall back to IPv4 for performance and correctness
       reasons.	If there are many routers to query, a timeout for every	router
       would make MRTG take too	long to	query them all.	And if,	for some
       reason, IPv6 connectivity to the	target is lost,	MRTG's error messages
       can help	figure out what	is wrong.

       cfgmaker	does fall back from IPv6 to IPv4. If IPv6 is enabled and
       cfgmaker	is given a hostname that resolves to both an IPv6 and an IPv4
       address,	it first tries to query	the target over	IPv6. If it receives
       no answer, it tries again using IPv4. If	the target answers, cfgmaker
       sets the	IPv4Only option	in the generated config	file.

IPv6 LIBRARIES
   Libraries required
       IPv6 support requires the Socket6 and INET6 Perl	modules. Both can be
       downloaded from CPAN:

       http://search.cpan.org/author/UMEMOTO/Socket6/

       http://search.cpan.org/author/MONDEJAR/INET6/

       If you use Debian, you will need	the packages libsocket6-perl and
       libio-socket-inet6-perl,	which are (or should soon be) in unstable.

       So far, IPv6 support has	been tested on Linux only, and only with
       Socket6 version 0.12. Also note that IPv6 won't work at all if you
       don't have INET6.pm version 2.00	or newer.

   Installing the libraries
       Building	and installing Socket6 and INET6 is very simple. For each
       module, just unpack the archive and then	do:

	perl Makefile.PL
	make

       and then:

	su
	make install

       If you have installed the libraries successfully, cfgmaker and mrtg
       should automatically detect them	and allow IPv6 support to be enabled.

AUTHOR
       Lorenzo Colitti <lorenzo	location colitti.com>

2.17.10				  2022-01-19			  MRTG-IPV6(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=mrtg-ipv6&sektion=1&manpath=FreeBSD+Ports+14.3.quarterly>

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