Package: arpreq
Python C extension to query the Kernel ARP cache for the MAC address of
a given IP address.UsageThearpreqmodule exposes two functionsarpreqandarpreqb, that
try to resolve a given IPv4 address into a MAC address by querying the ARP
cache of the Kernel.An IP address can only be resolved to a MAC address if it is on the same
subnet as your machine.Please note, that no ARP request packet is sent out by this module, only the
cache is queried. If the IP address hasn’t been communicated with recently,
there may not be cache entry for it. You can refresh the cache, by trying to
communicate with IP (e.g. by sending and ICMP Echo-Request aka ping) before
probing the ARP cache.Let’s assume your current machine has the address192.0.2.10and
another machine with the address192.0.2.1is on the same subnet:>>>importarpreq>>>arpreq.arpreq('192.0.2.1')'00:11:22:33:44:55'If an IP address can not be resolved to an MAC address, None is returned.>>>arpreq.arpreq('8.8.8.8')isNoneTrueIP addresses may be also be specified as int or rich IP address data type
of the commonipaddr,ipaddress, ornetaddrmodules.>>>arpreq.arpreq(0x7F000001)'00:00:00:00:00:00'>>>importnetaddr>>>arpreq.arpreq(netaddr.IPAddress('127.0.0.1'))'00:00:00:00:00:00'>>>importipaddr# on Python 2>>>arpreq.arpreq(ipaddr.IPv4Address('127.0.0.1'))'00:00:00:00:00:00'>>>importipaddress>>>arpreq.arpreq(ipaddress.IPv4Address(u'127.0.0.1'))'00:00:00:00:00:00'Instead of a hexadecimal string representation, MAC addresses may also be
returned as native bytes when using thearpreqbfunction:>>>arpreq.arpreqb('127.0.0.1')b'\x00\x00\x00\x00\x00\x00'>>>arpreq.arpreqb('192.0.2.1')b'\x00\x11"3DU'Supported PlatformsThis extension has only been tested on Linux, it should however work on
any platform that supports theSIOCGARPioctl, which is virtually
every BSD and Linux. MacOS X does not work anymore, because Apple has
removed the interface.IPv6-Support and AlternativesTheSIOCGARPioctl interface described inarp(7)and used by this
module is a fairly old mechanism and as the name suggests, works only for ARP
and therefore only for IPv4. For IPv6 the Linux Kernel uses the modern and
extensiblertnetlink(7)interface based onnetlink(7)to manage
link-layer neighbor information.Until Linux 5.0 however only whole tables could be dumped viartnetlink(7)RTM_GETNEIGHmessages and it was not possible to query for specific IP
addresses. If entries need to be queried often or there are a lot of entries,
this might be too inefficient. As an optimization querying the tables only
once and subscribing to change events afterwards was possible, albeit more
complicated. SinceLinux 5.0RTM_GETNEIGHmessages can be used to query specific addresses on specific
interfaces.The pure-python netlink implementationpyroute2can be used to access thertnetlink(7)and othernetlink(7)interfaces.Since version 0.5.14specific addresses can be queried.Changelogv0.3.4 (2021-12-21)Enable PEP-489 on PyPy3 5.8 and laterImprove testingMove Debian packaging to separate branchesAdd docker-compose infrastructure for different manylinux variantsAddarpreqbfunction, which returns the MAC as PythonbytesobjectSupport 8-byte/64-bit MAC addressesv0.3.3 (2017-05-03)Disable PEP-489 on PyPy3Disable PyModule_GetState on PyPy3Provide a Debian packagev0.3.2 (2017-05-03)Support point-to-point veth pairs (See #6)Accept unicode objects on Python 2 and bytes objects on Python 3 (See #5)Some test improvementsv0.3.1 (2016-07-06)Don’t use private _PyErr_ChainExceptions (breaks on Debian Jessie)v0.3.0 (2016-06-26)Use PEP 489 multi-phase extension module initialization on Python 3.5+Close socket if module initialization failedCode cleanupv0.2.1 (2016-06-26)Fix memset overflowv0.2.0 (2016-06-09)Provide Python wheelsSupport int and rich IP address objects as IP address argumentsRelease the GIL during arpreqAdd units testsRework MAC string creationRestructure module initializationv0.1.0 (2015-11-28)Initial release