Physical path
Redacted ISP-to-client sketch with device names, ports, and cables.
Separate modem, router, switch, and access-point roles
Use this flow when the network path is unclear or multiple boxes appear to be doing the same job. The first goal is a redacted topology, not a reset or configuration change.
Preserve the baseline: do not factory-reset equipment, change DHCP/NAT/VLAN/firewall settings, or switch router/AP modes until the current path and rollback evidence are recorded.
What this flow is for
The modem, gateway, router, firewall, switch, mesh node, or access point roles are unclear. One all-in-one box may provide several roles, while a second router can accidentally create duplicate DHCP or NAT.
First safe checks
- Start at the ISP handoff and label each physical box and cable path.
- Identify the default gateway, DHCP server, NAT/firewall owner, switch path, and Wi-Fi owner.
- Check WAN/Internet versus LAN/uplink ports without changing cabling.
- Look for more than one DHCP server, private gateway, or routing device.
- Record the topology and management path before changing anything.
Best evidence
Capture this without secrets
Client roles
Default gateway, DHCP server, and Wi-Fi owner from one client.
Device claims
Model and intended role for each modem, gateway, router, switch, AP, or mesh node.
Likely causes
Most likely problem buckets
All-in-one gateway
One ISP gateway may already combine modem, router, switch, firewall, and Wi-Fi.
Duplicate routing
A second router or mesh node may be assigning addresses or performing NAT.
Wrong-side uplink
A switch or access point may be connected to the wrong gateway side or missing its uplink.
Missing map
The network may work, but the system map is stale or undocumented.
Next safe steps
Take one step at a time
ACT-NET-020
Create a redacted ISP-to-client path sketch and label each physical cable.
ACT-NET-021
Confirm the client default gateway, DHCP server, and Wi-Fi owner.
ACT-NET-022
Compare observed roles with the intended design and note duplicate DHCP/NAT evidence.
ACT-NET-023
Document one reversible change or hand off managed-network role changes.
Best follow-up ask
Which device connects to the ISP handoff, and which device provides the client default gateway and DHCP?
When to stop and hand off
Escalate before changing DHCP, NAT, VLAN, firewall, cabling, or managed access-point roles without a preserved baseline and rollback.
Source provenance
Reviewed against official networking basics
This vendor-neutral flow uses Cisco guidance that distinguishes routers, switches, access points, and wireless routers while recognizing that modern devices can combine roles.
Map the network
Record the gateway, switch, access points, clients, and relationships privately.
Open private discoveryContinue in support chat
The support assistant can ask for a redacted topology without accepting credentials.
Open support chat