Wake‑on‑LAN proxies wake up remote PCs without using directed broadcasts.

Why WOL proxies

The WOL protocol only allows computers to be woken up within the local IP segment. To enable remote computers to be woken up across network segments—and even over the Internet—the Auto Shutdown Manager Server offers two completely different approaches: Directed Broadcasts and WOL Proxies.

Directed broadcasts

The wake‑up packets are sent directly to the endpoint router and triggered there as local broadcasts. However, this procedure is not permitted in most companies for security reasons.

WOL proxies

In practice, WOL proxies are used in the vast majority of cases. For this purpose, a computer or a device that supports Java—such as a Raspberry Pi—is placed in the remote network segment for continuous operation (24/7). When required, the Auto Shutdown Manager server instructs it to wake up any computer that is relatively local via Wake‑on‑LAN. It is sensible to use machines that are already running continuously (e.g., local servers) or devices with very low power consumption. In small networks, this can be configured manually; for larger, more complex networks, the automatic generation of WOL proxies described below is useful.

WOLPROXY20

Automatic WOL proxy generation and monitoring

The purpose of automatic WOL proxy generation, optimization, monitoring, and maintenance is to ensure that the WOL server operates as reliably and maintenance‑free as possible. The analysis can be run daily or on a schedule of your choosing to promptly identify network changes and, if necessary, automatically optimise the selection of WOL proxies.

How the automatic WOL proxy generator works

The automatic search for suitable computers to act as WOL proxies is based on a fully automated analysis of the entire network infrastructure, including computer types, current runtimes, group membership, and other settings described below. Administrators can exclude unwanted computer types, such as notebooks or purely virtual machines, and can also exclude specific network segments from automatic proxy generation.

A filter allows entire groups to be excluded or marked as preferred. Preference is given to clients that are always on. Typical preferred groups are servers that run 24/7.

Administrators can still manually designate individual network segments and WOL proxies. Manual selections have the highest priority and are considered during automatic generation and optimisation. Administrators may also define a minimum segment size; otherwise, generating WOL proxies for very small segments with only two or three clients may be unnecessary. If Raspberry Pis or similar devices with the appropriate EnviProt WOL proxy drivers are used, they are automatically recognised and preferred as proxies.

A preview function gives administrators the opportunity to view the results in advance. For this, the generated proxy list is output as an Excel‑compatible CSV file.

Optimization

During the network analysis, care is taken to minimise the number of WOL proxies. This is achieved by detecting redundant subnets.

Example:

Network A is recognised as redundant, so no WOL proxy is generated for it because all clients can also be reached from network B.

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Conversely, the system seeks computers that can serve multiple subnets. For example, Computer R1 would be selected because, as a WOL proxy, it can serve all three network segments:

WOLAG op2

Reliability

If a WOL proxy PC fails, the Auto Shutdown Manager server searches for another currently running PC in the target network segment and promotes it to a temporary WOL proxy. If the original proxy does not respond for a specified period, it is automatically replaced by the next best candidate. This guarantees a seamless and reliable WOL infrastructure with no administrative effort.

Here you can find some more technical details and examples for Directed Broadcasts and for WOL Proxies.