ASUS ZenWiFi BE30000 - Random Boot Failures with Multi-Gig Internet (xport_init Timeout Bug)

[BoomJosh]

Hi All,

Following are the details and issue I am facing. Anyone facing similar issues and know a workaround.

Subject: ZenWiFi BE30000 - Random Boot Failures with Multi-Gig Internet (xport_init Timeout Bug)
Router Model: ASUS ZenWiFi BE30000 (BQ16_2566_2)
Firmware Version: 3.0.0.6_102_37026 (Build: Oct 30, 2025)
ISP Speed: 1.5 Gbps (1500 Mbps)
WAN Connection: 10Gbps Ethernet Port (Auto-negotiation)

Problem Summary​

When rebooting my router, it randomly fails to detect internet connectivity even though the ISP connection is active and working. The router requires multiple reboots (typically 2-4 attempts) before successfully establishing a WAN connection. This happens inconsistently - sometimes it works on the first boot, sometimes it takes several tries.

What I've Tried (That Didn't Work)​

• ✗ Replaced ethernet cable with brand new Cat6/Cat7 cable
• ✗ Power cycling modem first, waiting 60+ seconds before powering on router
• ✗ Factory reset and reconfiguration
• ✗ Different ethernet cables
• ✗ Reseating all connections

The issue persists despite all hardware being brand new and properly connected.

Root Cause Analysis (Based on System Logs)​

After extensive log analysis, I've identified the root cause is a firmware bug in the xport_init (crossbar switch initialization) routine during boot.

The Technical Details:​

During router boot, this sequence occurs:

1. Router's internal switch port initializes and attempts to bring up the WAN (eth0) link
2. The firmware has a hardcoded timeout waiting for the physical link to establish
3. If the 10Gbps link negotiation takes too long, the init process times out
4. The boot continues but WAN is marked as "down" even though the modem is ready

Evidence from System Logs:
Dec 31 18:02:01 kernel: [NTC xport] xport_init: Time out waiting for link up on port 4<br>Dec 31 18:02:01 kernel: eth0 (Int switch port: 7) (Logical Port: 7) (phyId: 13) Link DOWN.<br>
This timeout occurs before the physical link negotiation completes with my ISP modem.

Failed Boot Pattern:​

When boot fails to connect, the logs show:
18:03:48 - eth0 Link DOWN<br>18:03:51 - eth0 Link Up at 10000 mbps<br>18:03:53 - WAN(0) link up<br>18:04:11 - eth0 Link DOWN again (link still unstable)<br>18:04:17 - WAN(0) link down<br>
The router gives up because the link hasn't fully stabilized during the boot window.

Successful Boot Pattern:​

When boot succeeds, the logs show:
18:02:03 - WAN(0) link down<br>18:02:06 - eth0 Link Up at 10000 mbps<br>18:02:14 - restart_wan_if triggered<br>18:02:24 - WAN was restored<br>12:30:55 - DHCP client bound to IP address ✓<br>
In this case, the 10Gbps negotiation completed just fast enough to fit within the timeout.

Why This Happens​

10Gbps Ethernet link negotiation (802.3an/802.3bz) is more complex than 1Gbps negotiation:

• 1Gbps link negotiation: ~1-2 seconds
• 10Gbps link negotiation: ~5-10 seconds (requires multiple handshake rounds)

The firmware's xport_init timeout appears to be only 1-3 seconds, which is insufficient for reliable 10Gbps negotiation. The actual negotiation time varies based on:

• Cable quality
• Modem response time
• Electrical noise
• Temperature

This creates the "random" behavior - sometimes the negotiation completes just fast enough, sometimes it's 1-2 seconds too slow and hits the timeout.

Thanks
Please provide your inputs