Lab 2: Repair No Internet After an Office Move

Scenario: Moved Desks, Broken Access

A group of users moved to a new row of desks over the weekend. On Monday morning, two users report no Internet, one user can print but not browse external sites, and another user works normally. The office uses wired Ethernet to wall jacks, a patch panel in the closet, an access switch, and a router or firewall as the default gateway. Your goal is not to redesign the network; it is to gather evidence, repair simple physical issues, and escalate accurately if the problem points to infrastructure configuration.

Begin with scope. Ask whether the problem affects one user, one desk row, one switch, one application, or the whole site. Check a known-good device in the same area. If one device works at the same wall jack with the same cable, the issue may be the original endpoint. If the same endpoint works at a known-good jack, the issue may be the original jack, patch, switch port, or VLAN. This comparison prevents random changes and helps the ticket tell a clear story.

Inspect the physical path before assuming software failure. Verify the endpoint cable is firmly seated and not damaged. Confirm the wall jack label, trace the corresponding patch panel port if permitted, and check whether the patch cable in the closet lands on the intended switch. A common move-day error is patching the desk into an unused port, a voice-only port, a guest network, or a switch that has no active uplink. Link and activity LEDs should be observed on both the endpoint and switch when accessible. If a cable or patch is obviously bad, replace it with a known-good cable and retest.

Next compare IP settings. A healthy office client might have 10.20.30.145/24, gateway 10.20.30.1, and DNS servers from DHCP. A failing client with 169.254.x.x is not receiving DHCP. A failing client with a guest-range address, such as 10.99.10.x, may be on the wrong VLAN. A client with a correct IP address but a blank or wrong gateway will fail off-subnet traffic. A client that can ping the gateway and an external IP address but cannot open names such as www.cisco.com likely has a DNS problem.

Use layered tests. Check link, then IP address, then ping the default gateway, then test another local resource, then test an external IP, then test a DNS name. Record both failures and successes. For example, 'link up, DHCP address 10.20.30.151, gateway ping succeeds, 8.8.8.8 ping fails for two users on switch ports 17 and 18, known-good user on port 22 works' is much more useful than 'Internet down.'

Escalate when the evidence points beyond your access. If several newly patched jacks land on switch ports in the wrong VLAN, a network engineer may need to change port configuration. If the switch uplink is down, someone may need to inspect fiber, transceivers, trunk settings, or upstream switch status. If only external traffic fails while local gateway tests succeed, escalate with routing, firewall, NAT, or ISP evidence. Include recent move timing, affected users, jack labels, switch ports, IP settings, and commands or tests already performed.

Study Checkpoint

• Topic: Lab 2: Repair No Internet After an Office Move.
• Verify the official Cisco concept before memorizing a shortcut.
• Practice the technician action: observe, document, test, fix when supported, or escalate.