#1124792 traceroute with TCP/UDP fails to report final hop

Package:
traceroute
Source:
traceroute
Description:
Traces the route taken by packets over an IPv4/IPv6 network
Submitter:
Alan Brady
Date:
2026-01-06 19:37:03 UTC
Severity:
normal
#1124792#5
Date:
2026-01-06 19:34:57 UTC
From:
To:
In a 3 router configuration:

r1 --- r2 --- r3

Attempting to traceroute from r1 to r3 succeeds as expected using ICMP. However, using TCP/UDP, the final hop fails to get reported contrary to expectation. The packets appear to be received on the final hop but there's no return.