A firewall address of 192.168.1.101 can be pinged from a router but, when running a traceroute to it, this output is received. 1 2 3 4 5 6 7 8 9 10 What is the cause of this issue?

Traceroute typically uses UDP probes destined for high-numbered ports on the target. If the firewall is configured to block all UDP traffic, it will drop these probes and not generate an ICMP Port Unreachable message back to the source, resulting in the `***` output even if ICMP pings succeed.

The ability to ping the firewall indicates that ICMP Echo Request/Reply traffic is allowed, so blocking all ICMP traffic is not the issue.

Since ping (ICMP Echo) functions correctly, the basic firewall rule allowing ICMP traffic appears to be working for at least that type of ICMP.

While traceroute involves ICMP messages (Time Exceeded, Port Unreachable), the primary traffic type sent by the traceroute utility itself is often UDP, and blocking these UDP probes is a more direct and comprehensive reason for traceroute failure when ping works.