ARRIS-branded equipment is common in cable internet deployments and includes standalone cable modems, modem/router gateways, and ISP-customized devices. That distinction matters because a modem status page and a Wi-Fi router admin page are not the same thing.
Common local addresses
Combined gateways are often found on 192.168.0.1 or another private LAN gateway chosen by the provider. Standalone cable modems are frequently associated with 192.168.100.1 for diagnostic/status access even when the separate Wi-Fi router uses a different subnet.
Do not expect router settings on a modem-only device?
If 192.168.100.1 opens signal-level and connection-status information but no Wi-Fi menu, you may be looking at the modem rather than the router. Find the default gateway on your connected device to reach the router responsible for Wi-Fi and NAT.
ISP credentials vary
Provider-supplied gateways can use unique device access codes, printed credentials, apps, or ISP accounts. Use the label/provider documentation instead of assuming a universal ARRIS username/password.
ARRIS/SURFboard: modem diagnostics and gateway administration are different
ARRIS/SURFboard products range from standalone cable modems to combined cable gateways. 192.168.100.1 is heavily associated with modem/web-manager diagnostics, while gateway products can also expose Wi-Fi and routing settings. Identify whether the device is a modem-only bridge or an integrated router before looking for Wi-Fi controls.
Credentials vary by model and firmware
Validated ARRIS support articles show multiple authentication patterns across models: custom passwords, app-linked credentials, serial-number-derived values and older defaults. That is strong evidence against publishing one ARRIS password. Use the model-specific Web Manager article.
Signal pages
Downstream/upstream power, SNR, channel status and event logs can help separate coax/DOCSIS trouble from a router/Wi-Fi problem. Interpret values using current model/ISP guidance and capture evidence before resets if you are working with provider support.
Bridge Mode
On gateway models, Bridge Mode can disable routing/Wi-Fi so a separate router takes over. After changing modes, the network gateway seen by clients changes and local management reachability can differ. Make the change with a recovery plan.
SURFboard modem and gateway screens serve different jobs
ARRIS/SURFboard modem and gateway products; ISP variants can differ
- ARRIS/SURFboard modem and gateway products; ISP variants can differ Official source 1
Illustrative case: A modem-only status guide is used to look for parental controls. Identify the installed SURFboard model before expecting router features.
Documentation and scope