Listen to this Post
When running traceroute, you may encounter asterisks () in the output, indicating a non-responsive hop. This doesn’t always mean network failure—here’s why:
How Traceroute Works
1. TTL Mechanism:
traceroute google.com Linux tracert google.com Windows
– Sends packets with increasing Time-To-Live (TTL) values (1, 2, 3…).
– Each router decrements TTL by 1. If TTL=0, it replies with ICMP Time Exceeded.
2. Asterisks Appear When:
- The router blocks ICMP (common in firewalls).
- Rate-limiting ICMP replies.
- ACLs filter ICMP traffic.
You Should Know:
Linux Commands for Deeper Analysis
- Force ICMP/UDP:
traceroute -I google.com ICMP mode traceroute -U google.com -p 53 UDP mode (DNS port)
- Disable DNS Lookups (faster output):
traceroute -n google.com
- Alternative Tools:
mtr google.com Combines traceroute + ping tcptraceroute google.com 443 TCP-based traceroute
Windows Alternatives
pathping google.com Combines traceroute + latency stats
Packet Capture (Verify Traffic)
tcpdump -i eth0 icmp Linux ICMP capture tshark -i eth0 -Y "icmp" Wireshark CLI
Common Misconceptions
- Asterisks ≠ Packet Loss: Traffic may still flow.
- Backbone Routers: Often ignore traceroute for security.
- Use Multiple Tools: Cross-check with
ping,mtr, ortcptraceroute.
What Undercode Say
Traceroute is a diagnostic tool, not definitive proof of network health. Combine it with:
– Ping Tests:
ping -c 4 google.com
– Path Analysis:
ip route get google.com Check routing path
– Firewall Checks:
iptables -L -v Linux firewall rules
For Windows:
netsh advfirewall show allprofiles
Expected Output:
traceroute to google.com (142.250.190.46), 30 hops max, 60 byte packets 1 192.168.1.1 (192.168.1.1) 1.234 ms 2<br /> 3 10.10.10.1 (10.10.10.1) 5.678 ms Asterisks but next hop responds
Prediction
As networks prioritize security, ICMP-based tools like traceroute will become less reliable. Alternatives like TCP-based path analysis (e.g., tcptraceroute) or protocol-aware monitoring (e.g., mtr) will gain traction.
URLs for Further Reading:
IT/Security Reporter URL:
Reported By: Pdiazd Why – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
