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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 config-
     uration 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  ad-
     dresses  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 down-
     loaded 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  li-
     bio-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+15.1.quarterly>

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