GDMC Admin — LAN Restore + CBS250 Core
Problem
The admin building experienced full Internet loss and unstable internal communication due to a legacy Cisco SF200 switch and misconfigured firewall NAT.
Action
Replaced the SF200 with a Cisco CBS250-24P-4G, re-wired the rack, restored the Sophos XG firewall configuration, and implemented broadcast-storm control and VLAN cleanup.
Result
Network restored within one day; all ports 1 Gb Full Duplex, CRC errors 0, latency < 1 ms LAN; 95%+ uptime after one-week monitoring.