|+ Network interface card to use for address monitoring|
|+ Type of probe packets to use|
|+ Various timing paramaters (such as probe frequency)|
The configuration file follows the following general format:
# Comments Variable1=Value1 # Comments Variable2=Value2
The following configuration options are currently supported:
|This variable specifies the network interface that will be used for IPv6 address monitoring.|
|This variable specifies the pathname of the log file where address usage will be recorded. If left unspecified, the pathname defaults to /var/log/ipv6mon.log.|
This variable is used to specify the pathname of the lockfile (PID file) to be used to easily identify running instances of
.If left unspecified, it defaults to /var/run/ipv6mon.pid.
|This variable specifies the unprivileged username that will switch to (i.e., setuid), such that superuser privileges are released. If left unspecified, it defaults to ipv6mon|
|This variable specifies the unprivileged group that ipv6mon will switch to (i.e., setgid), such that superuser privileges are released. If left unspecified, it defaults to ipv6mon|
|This option specifies the format to be used for the timestamps that are included in the log file. Possible values are date and epoch. The former causes the tool to include the timestamps in the format “Sat Dec 24 05:24:50 2011”, whereas the latter causes the tool to include timestamps as the number of seconds since the Epoch. If left unspecified, this option defaults to date|
|This variable specifies the maximum number of addresses that ipv6mon will keep track of at any given time. Since ipv6mon keeps the list of currently-used addresses in memory (such that they can be probed on a regular basis), the variable MaxAddressEntries indirectly enforces a limit on the amount of system memory that ipv6mon will use.|
|This variable specifies the maximum number of "candidate addresses" that ipv6mon will create at any given time. If left unspecified, it defaults to MaxAddressEntries / 4.|
|This variable specifies the amount of time (in seconds) after which an IPv6 address will be considered “unused” if no response is received from that address.|
|This variable specifies the amount of time (in seconds) after which a “candidate” IPv6 address will be considered “unused” if no response is received from such address. Since candidate addresses are created as a result of a heuristics (rather than in response to packets originated from such addresses), CandidateAddressTimeout will typically be shorter than AddressTimeout , such that system resources are not tied to these (possibly unused) addresses for an unnecessarily long period of time.|
|This variable specifies the maximum amount of time (in seconds) that an address will remain “unprobed”. For obvious reasons, its value should be smaller than that of AddressTimeout and that of CandidateAddressTimeout , and should also usually account for more than one probe packet to be sent before an address is "timed out".|
|This variable specifies the amount of time (in seconds) between unicast probes sent to an IPv6 address. Once MaxUnprobedInterval seconds have elapsed without probing an addresses, unicast probes will be sent every UnicastProbeInterval seconds until a response is received or the address is timed out.|
This variable specifies the amount of time (in seconds) between ICMPv6 Echo Request probe packets sent to the all-nodes on-link multicast address (ff02::1). Multicast Echo Request packets can easily detect newly attached devices and probe existing devices. However, because they are sent to a multicast address, the interval should be long enough such that unnecessary traffic spikes are reduced.
Note: Some operating systems (notably Windows Vista and Windows 7) will not respond to ICMPv6 echo request messages sent to a multicast address. However, such systems can still be detected by means of probe packets that include an unsupported option of type 10xxxxxx.
This variable specifies the amount of time (in seconds) between ICMPv6 Echo Request probe packets (containing an unrecognized option in a Destination Options header) sent to the all-nodes on-link multicast address (ff02::1). Multicast Echo Request packets can easily detect newly attached devices and probe existing devices. However, because they are sent to a multicast address, the interval should be long enough such that unnecessary traffic spikes are reduced.
This variable specifies the type of probe packets that will be used for both unicast and multicast probes.
echo specifies that only regular ICMPv6 Echo Request messages should be used.
unrec specifies that only ICMPv6 Echo Request messages with an unsupported option should be used.
all specifies that both types of probe packets should be used. If left unspecified, this option defaults to
The following is a sample ipv6mon.conf file.
# # ipv6mon configuration file #
NetworkInterface=eth0 # Network Card to monitor AddressLogFile=/var/log/ipv6mon.log # Where to log address usage LockFile=/var/run/ipv6mon.pid # Where to write the daemons PID UnprivilegedUser=ipv6mon # Unprivileged user to switch to UnprivilegedGroup=ipv6mon # Unprivileged group to switch to TimestampFormat=date # Timestamps format MaxAddressEntries=2000 # Maximum number of IPv6 addresses #MaxCandidateEntries=1000 # Max. number of "candidate" addr AddressTimeout=90 # Address timeout value CandidateAddressTimeout=40 # Candidate Address Timeout MaxUnprobedInterval=40 # Max. unprobed time UnicastProbeInterval=15 # Time between unicast probes McastEchoProbeInterval=120 # Time between Mcast Echo Probes McastUnrecProbeInterval=120 # Time between Mcast Unrec Probes ProbeType=all # Probe types (echo, unrec, all)
The ipv6mon tool and the corresponding manual pages were produced by Fernando Gont <firstname.lastname@example.org>.
Copyright (c) 2011-2012 Fernando Gont.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being just "AUTHOR" and "COPYRIGHT", with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is available at <http://www.gnu.org/licenses/fdl.html>.