Runs enterprise networks and security for a living, and writes Shore Up to turn two decades of hands-on Linux, Windows and mail-server work into guides you can actually use.
This guide sets up QoS (Quality of Service) on a Palo Alto firewall so you can guarantee bandwidth to important traffic (say VoIP), cap bandwidth for greedy traffic (backups, streaming), and prioritise real-time flows during congestion. QoS on PAN-OS is enforced on the egress direction of an interface, which is the single most important thing to understand before you build anything — I cover it below.
This guide gives you a PowerShell script that walks a share tree, reads the NTFS access control list (ACL) on each folder, and reports every place where a broad identity — Everyone , Authenticated Users , Domain Users , BUILTIN\Users — has been granted Write, Modify, or Full Control. That combination is the classic definition of "oversharing," and this script's only job is to find it and write it to a CSV. It reads permissions. It does not change a single ACE.
When systemd hands a listening socket to a service, the kernel keeps completed connections in an accept queue until the service calls accept() on them. If the service falls behind — thread-starved, blocked on a slow database, whatever — that queue fills. Past the socket's backlog it silently drops or refuses connections. This guide sets up a small, read-only monitor that watches the accept-queue depth on your listening sockets and raises an alert before you hit that wall.
This guide configures the FortiGate's own DNS resolver to use FortiGuard servers, builds a DNS Filter security profile (FortiGuard category blocking, botnet C&C domain blocking, and an optional static domain block list), and applies that profile to an outbound firewall policy. The purpose is to stop clients from resolving known-malicious, botnet, and unwanted-category domains before a connection is ever made.
This guide builds a read-only PowerShell script that pulls failed logon events (Security log Event ID 4625 ) from a list of servers, keeps the ones that look like RDP attempts, and writes them to a dated HTML/CSV report you can review each morning. It optionally emails that report. It creates nothing and deletes nothing on the target servers — it only reads their Security logs.
This guide gives you a small bash script that rebuilds a Postfix transport map from its flat-file source, validates the configuration, and reloads Postfix so the new routing takes effect. postfix reload re-reads configuration and recycles daemons gracefully — it does not drop in-flight SMTP connections or stop the queue, which is why we use it instead of restart .
On 21 August 2026 Canonical pushed out a broad set of kernel security notices, and threaded through most of them is one identifier: CVE-2026-64531 , nicknamed OVSwrap , an Open vSwitch flaw in the Linux kernel that leads to local root. The oss-security post that carries the name declines AI crawlers , so I only have its subject line to confirm the classification — Linux kernel / OVS, local privilege escalation. The details of the write-up I can't quote, and won't guess at.
Suricata is a deep-packet inspection engine. In IDS mode it watches a copy of the traffic on an interface and raises alerts; in IPS mode it actively blocks hosts or drops packets that match a rule. That second mode is the dangerous one: a noisy or badly tuned rule can block a legitimate host — including your own management workstation — and cut production traffic. Treat this as a change to a live firewall, not a lab toy.
This guide builds two small PowerShell scripts. The first captures the current Windows Firewall ruleset to a CSV baseline . The second re-reads the live rules and reports which ones were added, removed, or changed since that baseline. Both scripts are read-only — they use Get-* cmdlets only and change no firewall rules, so running the audit cannot break connectivity.
This script is a read-only audit . It walks your virtual mailbox tree and a couple of mail config directories and reports three things: mailbox files or directories that are readable or writable by group/other, mailbox files not owned by the expected mail user, config files that contain secrets but aren't locked down, and the service account's login shell. It changes nothing — no chmod , no chown , no account edits. Remediation is a separate, manual step at the end that you run deliberately, one finding at a time.
This guide builds a two-node pfSense high-availability (HA) pair: one primary firewall that carries traffic and one secondary that takes over automatically if the primary fails. CARP provides the shared virtual IP addresses your clients use as their gateway, pfsync copies the firewall state table between nodes so existing connections survive a failover, and XMLRPC config sync keeps the secondary's configuration in step with the primary.
An auditor asks the same question every year: who was in which distribution list on this date? Clicking through each group in the admin center does not scale past a handful of groups, and it produces nothing you can hand over. This guide scripts a clean, point-in-time CSV of every distribution group and its members.
This guide gives you a read-only Python script that parses a Postfix mail log and reports two things: authenticated senders (SASL users) who sent an unusually large number of messages or recipients — the classic signature of a compromised mailbox being used to blast spam — and source IPs that keep tripping "Relay access denied", which is relay probing. The script does not change anything : it reads the log, counts, and prints a report. It never touches Postfix config, never disables an account, never blocks an IP.
