Sat Jun 03, 2023 3:57 pm
It's not normal but it's understandable ... kind of.
Traceroute shows 100% packet loss at first hop which means that traceroute tool has no means of discovering that hop's IP address.
BTW, when running traceroute tool, first hop is not your router, it's first upstream router (your ISP's device).
Now why does this happen? Link is obviously not broken or else subsequent hops would show same results. Which then means that that node likely doesn't send ICMP time exceeded messages when it discards packets with TTL reaching 0 (note, dropping those packets is correct action). Excuse for such behaviour is that sending ICMP time exceeded messages is often task of general purpose processor (even if other tasks are done by ASICs) and can thus be a heavy burden. Some admins, though, disable any ICMP handling altogether just because they were taught that ICMP is not useful and only abused in context of hacking attacks.