XArp was a specialist tool for detecting ARP spoofing on local networks. If you remember XArp.net or are looking for an XArp alternative, the useful starting point is the problem it addressed: devices receiving misleading information about which hardware address belongs to a local IP address.
This guide preserves the project’s context, explains ARP poisoning detection and compares current approaches to protecting a network. It is an independent Impulsec resource, not an official XArp support or download page.
What was XArp?
XArp was known as “Advanced ARP Spoofing Detection” and was associated with developer Christoph Mayer and the XArp.net website. A 2021 research paper on ARP attack detection cites Mayer’s XArp resource and discusses XArp alongside arpwatch as a software approach to detecting the problem. That provides a documented historical reference, rather than a claim about when the project first launched.
Its purpose was narrower than a general antivirus package or a VPN: identifying suspicious activity involving the Address Resolution Protocol. That distinction still matters when choosing a replacement. A packet analyser, an address-change monitor and a switch security feature each solve a different part of the problem.
Current status: XArp should be treated as legacy software. At this article’s September 2026 review, we could not verify a current developer-supported release channel or a formal retirement announcement. We therefore do not give a discontinuation date, endorse old installers or claim compatibility with current operating systems. A surviving download listing alone does not establish ongoing support.
What are ARP spoofing and ARP poisoning?
On an IPv4 local network, a device often needs a destination’s hardware address, also called its MAC address, before it can send an Ethernet frame. ARP supplies that mapping. For traffic going outside the local subnet, the relevant mapping is usually the default gateway’s IP address to its MAC address. The protocol is specified in RFC 826.
ARP spoofing means sending misleading ARP information. ARP poisoning describes the resulting corruption of a device’s cached IP-to-MAC mappings. The terms are often used interchangeably. For example, a false mapping can cause a device to send gateway-bound traffic to another machine on the local network.
Possible consequences include traffic interception, interference and loss of connectivity. Interception does not automatically reveal properly encrypted application data: correctly validated TLS protects application traffic against eavesdropping and alteration. Encryption also does not stop an intermediary from dropping packets. See the TLS protocol specification for its security objectives.
ARP is different from DHCP. DHCP supplies configuration such as an IP address, gateway and DNS servers; ARP resolves local IPv4 addresses to hardware addresses. Our guide to DHCP options and network security explains the configuration side.
How ARP poisoning detection works
Detection looks for evidence that an address mapping is unexpected or inconsistent. The value of an alert depends on knowing what the network normally looks like and whether the monitoring device can see the relevant traffic.
- An important IP address, such as the gateway, suddenly appears with a different MAC address.
- More than one device appears to claim the same IPv4 address.
- An IP-to-MAC mapping repeatedly changes between different devices.
- ARP traffic patterns differ from the network’s established baseline.
These are reasons to investigate, not automatic proof of an attack. Replacing a router, a planned failover, virtualisation changes or an accidental duplicate IP address can also produce unusual mappings. Check the device inventory and recent changes before deciding what an alert means.
Visibility is another limit. A capture on one laptop does not necessarily include every device’s unicast traffic on a switched network. Monitoring multiple network segments requires an appropriate sensor or capture arrangement for each relevant area.
XArp alternatives: choose by the job you need done
There is no single replacement that makes packet inspection, continuous alerting and enforcement interchangeable. The following options are documented approaches, not a hands-on performance ranking.
| Approach | Useful for | Main limitation |
|---|---|---|
| Wireshark | Inspecting ARP packets during an investigation | Does not automatically block attacks |
| arpwatch | Monitoring IP-to-MAC changes and generating notices | Changes need interpretation; visibility depends on deployment |
| Dynamic ARP Inspection | Rejecting invalid ARP packets on supported managed switches | Requires compatible hardware and careful configuration |
Wireshark: investigate suspicious ARP traffic
Wireshark is a maintained packet analyser available through its official download channels. For a capture from your own network or an authorised investigation, the display filter arp focuses the view on ARP packets. Its ARP filter reference also documents fields for duplicate-address and packet-storm indications.
Use the evidence to compare observed sender addresses with your known gateway and device inventory. Wireshark is useful for understanding what happened, but its official introduction explicitly distinguishes it from an intrusion detection system. It is not a set-and-forget replacement for alerting or network enforcement.
arpwatch: monitor address changes
arpwatch records Ethernet and IP address pairings and can report changes by email. Its documented notices include new stations, changed Ethernet addresses and mappings that alternate between devices. The distribution documentation for arpwatch describes these behaviours and configuration options.
This makes it useful for administrators who want ongoing awareness of changes on a local network. Obtain it through a trusted package repository for a supported operating system; installing a specialist security distribution is not necessary just to use an available package. Plan the sensor’s visibility, alert delivery and baseline. arpwatch reports observations rather than stopping suspicious traffic.
Dynamic ARP Inspection: enforce checks on the network
For compatible managed switches, Dynamic ARP Inspection, or DAI, can validate ARP messages and discard invalid ones. A common deployment uses DHCP snooping bindings to check whether an IP-to-MAC claim matches an expected device. Cisco’s DAI documentation explains the relationship between inspection, bindings and trusted interfaces.
DAI is an infrastructure control, not desktop software. Static-address devices and uplinks need an explicit plan, and features vary by switch platform. Review the documentation for your model and test before deployment: an incomplete binding or trust configuration can interrupt legitimate connectivity.
Does a VPN protect against ARP spoofing?
A VPN can encrypt traffic carried inside its tunnel, which can reduce exposure on an untrusted local network. It does not authenticate ARP messages, repair a poisoned ARP cache or guarantee that the local network will remain available. Traffic outside the tunnel also needs its own protections.
Our VPN privacy guide covers that separate privacy layer. A VPN is complementary to local network security; it is not an XArp replacement or an ARP poisoning detector.
Practical protection for home and business networks
- For home users: keep the router and operating systems supported and updated, use strong Wi-Fi security, and separate untrusted guest devices where the router supports it. These measures reduce exposure but do not make ARP itself authenticated.
- For administrators: maintain an address inventory, monitor changes, separate appropriate network segments and assess DAI on supported switches.
- If an alert appears: compare it with authorised changes and known gateway details. On a managed network, send the evidence to the network team. Avoid entering sensitive information over a connection you suspect is compromised.
- For learning: inspect normal ARP traffic in an isolated network you control. Keep experiments and packet captures away from other people’s networks and data.
Finally, ARP coverage is not complete IP network coverage. IPv6 uses Neighbor Discovery, described in RFC 4861, rather than IPv4 ARP. A mixed IPv4 and IPv6 environment needs controls appropriate to both.
Frequently asked questions
What was XArp used for?
XArp was used to detect suspicious Address Resolution Protocol activity, including signs of ARP spoofing on local networks. It was a specialist detection tool rather than a general antivirus product or VPN.
Is XArp still supported?
We could not verify a current developer-supported release channel or a formal retirement announcement at our September 2026 review. Treat it as legacy software and do not assume an old download listing proves current support or compatibility.
What can I use instead of XArp?
Use Wireshark to investigate packets, arpwatch to monitor IP-to-MAC address changes, or Dynamic ARP Inspection on supported managed switches to enforce checks. These options perform different jobs and are not direct equivalents.
Does a VPN stop ARP poisoning?
A VPN can protect traffic carried inside its encrypted tunnel, but it does not stop false ARP messages or repair poisoned address mappings. It cannot guarantee connectivity when a local attacker disrupts traffic.
Does a changed MAC address prove ARP spoofing?
No. Router replacement, failover, virtualisation changes and addressing mistakes can also produce unusual mappings. Compare alerts with the network inventory and authorised changes before concluding that an attack occurred.
Can Impulsec provide an official XArp download?
No. This is an independent historical and educational resource. It is not an official XArp distribution or support channel and does not provide XArp installers.
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Stuart Kerr Spindlow is Impulsec’s Publisher, Chief Editor and Lead Reviewer. He writes and maintains coverage of consumer cybersecurity and digital-safety software, with a focus on practical suitability, limitations and the evidence behind product claims. Read Stuart’s full profile.