1MRTG-IPV6(1) mrtg MRTG-IPV6(1)
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6 mrtg-ipv6 - IPv6 support in MRTG
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9 MRTG and cfgmaker support SNMP over IPv6. IPv6 targets can be specified
10 by hostname or IPv6 address, and if the required libraries are present
11 (see below), queries will use IPv6.
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14 Enabling IPv6
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16 IPv6 is currently disabled by default and must be explicitly enabled.
17 In MRTG this is done by turning on the EnableIPv6 global option in the
18 configuration file. In cfgmaker, it is enabled with the --enable-ipv6
19 command-line option.
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21 If IPv6 is disabled, MRTG and cfgmaker should behave in exactly the
22 same way as previous versions. So the addition of IPv6 support should
23 have no effect on existing MRTG setups unless IPv6 is enabled.
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25 IPv6 support requires the Socket6 and INET6 libraries (see below). If
26 MRTG can't find them, IPv6 is disabled.
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28 Specifying IPv6 targets
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30 IPv6 targets may be specified by name or IPv6 address. Numeric IPv6
31 addresses may be used with both cfgmaker and MRTG, but they must be
32 enclosed in square brackets.
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34 For example, a target could be specified as:
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36 public@[2001:760:4::]:161
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38 Hostnames work as expected: first an IPv6 name lookup is tried, then an
39 IPv4 lookup.
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41 Targets that do not support SNMP over IPv6
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43 Many targets (this currently includes all Cisco routers) do not yet
44 support SNMP over IPv6 and must be monitored over IPv4. This can cause
45 problems if you specify a target through its DNS name and the name maps
46 to both the IPv6 address and the IPv4 address of the target: MRTG will
47 only try IPv6, and will fail.
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49 To query these targets, use the IPv4Only per-target option, which tells
50 MRTG not to use SNMP over IPv6 for the target.
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52 MRTG does not fall back to IPv4 for performance and correctness rea‐
53 sons. If there are many routers to query, a timeout for every router
54 would make MRTG take too long to query them all. And if, for some rea‐
55 son, IPv6 connectivity to the target is lost, MRTG's error messages can
56 help figure out what is wrong.
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58 cfgmaker does fall back from IPv6 to IPv4. If IPv6 is enabled and cfg‐
59 maker is given a hostname that resolves to both an IPv6 and an IPv4
60 address, it first tries to query the target over IPv6. If it receives
61 no answer, it tries again using IPv4. If the target answers, cfgmaker
62 sets the IPv4Only option in the generated config file.
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65 Libraries required
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67 IPv6 support requires the Socket6 and INET6 Perl modules. Both can be
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70 http://search.cpan.org/author/UMEMOTO/Socket6/
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72 http://search.cpan.org/author/MONDEJAR/INET6/
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74 If you use Debian, you will need the packages libsocket6-perl and
75 libio-socket-inet6-perl, which are (or should soon be) in unstable.
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77 So far, IPv6 support has been tested on Linux only, and only with
78 Socket6 version 0.12. Also note that IPv6 won't work at all if you
79 don't have INET6.pm version 2.00 or newer.
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81 Installing the libraries
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83 Building and installing Socket6 and INET6 is very simple. For each mod‐
84 ule, just unpack the archive and then do:
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86 perl Makefile.PL
87 make
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89 and then:
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91 su
92 make install
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94 If you have installed the libraries successfully, cfgmaker and mrtg
95 should automatically detect them and allow IPv6 support to be enabled.
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98 Lorenzo Colitti <lorenzo location colitti.com>
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1022.16.2 2008-05-16 MRTG-IPV6(1)