How to enter the login page of the legacy device?

Zyxel_Jeff

Sometimes you might encounter a situation that using the latest version browser and cannot enter the login page of the legacy device which is end-of-life (such as ZyWALL USG 100 or other legacy devices). This article will guide you on how to resolve this situation.

The Chrome browser would return the below error message:

ERR_SSL_VERSION_OR_CIPHER_MISMATCH

The Firefox browser would return the below error message:

Error code: SSL_ERROR_UNSUPPORTED_VERSION

The Edge browser would return the below error message:

ERR_SSL_VERSION_OR_CIPHER_MISMATCH

Why the browser cannot enter the login page of the legacy device?

The common reason is due to the browser doesn’t support the lower TLS version of the legacy device for some security considerations. Just as the error message captured from Chrome browser, it indicates the browser doesn’t support the protocol version.

If we analyze the captured packet, we can find the root cause is the browser doesn’t support TLS version 1 during the SSL/TLS handshake procedure.

How to resolve it?

Use Zywall/USG Series - v3.30P9 (WK48) firmware that supports TLS1.2 protocol or use the Edge browser in IE (Internet Explorer) Mode to login to the legacy device for a workaround solution. The following example is demonstrated by ZyWALL USG 100 with V 3.30(AQQ.7) firmware and the browser is Microsoft Edge with Version 108.0.1462.46 (Official build) (64-bit).

STEP1. Enter the device login page via the Edge browser and click “Reload tab in Internet Explorer mode” on the upper right corner .

STEP2. Trust the device certificate and continue to browse the page.

STEP3. Then can enter the login page and login the device without problem.

THE ULTIMATE SOLUTION

Along with the increase of network security threat, old legacy end-of-life devices might not have enough capability to defend against the present network security threats. So, the ultimate solution is that we strongly advise users to upgrade old legacy devices to the latest ZyXEL products for better network efficiency and security.