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Month: September 2026

Locking unmanaged tenants to their IP: anti-spoofing for dedicated servers and Proxmox VMs (MikroTik, Cisco Nexus, Proxmox)

28/09/2026 by chris

How we stop unmanaged dedicated servers and VMs from adding extra IPs, changing MACs, ARP/NDP spoofing or running rogue DHCP/RA on a shared /24 — with MikroTik raw rules, Cisco Nexus port-security and the Proxmox VE firewall. Verified on production, with the gotchas.

Categories linux, network, security

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Recent Posts

  • Locking unmanaged tenants to their IP: anti-spoofing for dedicated servers and Proxmox VMs (MikroTik, Cisco Nexus, Proxmox) 28/09/2026
  • Enabling SELinux on a Server That Had It Disabled for Years — And Somehow Nothing Broke 22/08/2026
  • Updating a Forgotten BookStack: 15 Months, 1,371 Files and a Unix User That Didn’t Exist 22/08/2026
  • AlmaLinux 8 → 9 → 10 with ELevate: The Upgrade That Actually Worked 22/08/2026
  • Building a (Better) Admin UI for a Security Daemon 12/08/2026
  • GhostLock (CVE-2026-43499): “no mitigation” is true for the bug — not for the exploit chain 09/07/2026
  • Coming Soon to BitNinja. Already in Production in CFM. 08/07/2026
  • AlmaLinux 10: Dual EFI + mdadm RAID1 on Bare Metal (or: How I Spent My Friday Evening Arguing With a Boot Loader) 26/06/2026
  • I Taught an AI to Read My Analytics. Then It Started Doing My Marketing. 20/06/2026
  • Wildcard SSL with Let’s Encrypt: One Cert, Multiple Internal Hosts 01/06/2026
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