Hi all,
I’m having a persistent issue with a Vigor 2962 and wanted to see if anyone else has experienced similar behaviour or has any insight.
The router intermittently becomes unreachable on the LAN, while the rest of the LAN continues to work normally.

When this happens:
I cannot ping the router’s LAN IP.
I can still ping and communicate with other LAN devices
Internet traffic stops.
The web UI becomes unreachable.
Attempting to log into the UI frequently causes the router to reboot

Ping behaviour (key detail):
Long periods of ICMP timeouts to the router
Followed by very delayed replies (seconds to tens of seconds)
Duplicate ICMP replies marked as DUP!, suggesting ICMP requests were queued internally and released later
Occasionally I see ping: sendto: Host is down, which looks like ARP failing when the router stops responding
TTL on replies is always 255, so this is definitely the router responding directly, not routing asymmetry.
This feels very much like a control-plane issue: LAN switching continues, but management/ICMP/ARP stall.

What I’ve tried so far:
Full factory reset (no config restored)
Downgrading to older firmware versionsIssue persists regardless of configuration
LAN cabling and switching verified; issue is isolated to the router itself
The issue seems to worsen over time — freezes become longer, and delayed ICMP replies can arrive minutes later.
Questions:Has anyone seen similar behaviour on a 2962?Are there known firmware versions with CPU / memory exhaustion or ICMP queuing issues?
Any features known to cause this (DoS defence, firewall logging, VPN, etc.)?
Could this indicate failing hardware (RAM / CPU / thermal)?The unit is still under warranty, but I’d like to understand whether this is a known firmware issue or something others have encountered before proceeding further.Thanks in advance for any insight. 

Quick update after further investigation and syslog analysis.

I’ve now reviewed the router syslog in detail and correlated it with continuous ping monitoring to the router’s LAN IP.

Key findings:
• During periods where the router becomes unreachable on LAN (no ICMP, no web UI), other LAN devices remain reachable and traffic continues to flow.

• Syslog shows normal LAN and WAN activity up to the point of failure, but then logging simply pauses there is no clean reboot, watchdog reset, or kernel panic logged.

• PPPoE LCP echo traffic continues during some of these periods, indicating the router is still partially alive.

• Ping monitoring shows long stretches of ICMP timeouts followed by very delayed ICMP replies (seconds to minutes later) marked as DUP!, strongly suggesting ICMP requests are being queued internally while the router is unresponsive.

• I also see occasional Host is down errors, consistent with ARP not being serviced when the router locks up.

Accessing the web UI often worsens the issue:
• UI becomes extremely slow
• Logging in frequently causes the router to reboot
• This occurs even after a factory reset and across multiple firmware versions (including downgrades)
At this point it looks like a control-plane starvation or lockup, where switching and forwarding continue but management, ARP, and ICMP stall.
Given the behaviour persists across firmware and clean configuration, this is starting to look like a hardware issue (RAM / CPU / internal bus instability) rather than config-related.

If anyone has seen similar behaviour on a Vigor 2962, or knows of known issues related to management-plane lockups or hardware degradation on these units, I’d appreciate hearing your experience.

I’ve now raised this with DrayTek support under warranty and will update the thread with their response.