ICMPv6 measurements for Italian operators (ASNs)

How to read this table

• Click the ASN in the leftmost column to open that AS' full detail page (per-vantage paths, RFC 4890 verdict, IXP peering, active Type-2 test, and the per-hop diagnostics).
• Hover the Classification cell to see the full traceroute for that row, with reverse-DNS hostnames and the AS each hop belongs to.
• Last hop is the highest hop number that answered - a Time-Exceeded from an intermediate router, or an Echo Reply from the target itself. It's how deep we got into the path before responses stopped. A larger number means visibility further along.
• The ✓ check mark next to Last hop means traceroute reached the actual target IP. No check mark means the path went silent before the target, even if some intermediate hops responded.
• Filter likely at tells you where responses end. destination AS… means the destination network itself is filtering. past AS X (Y) means AS X did reply - the silence begins on the next hop (some unknown router/AS downstream). The named AS is not the one filtering; it's the last one we can see.
• min PMTU = lowest path-MTU value observed by tracepath -6; 1500 means no PMTUD event was triggered on that path.
• A RFC 4890 ✓ badge means the active Type 2 test proved the destination accepts and acts on inbound ICMPv6 Packet-Too-Big. A RFC 4890 ✗ badge means the test proved otherwise, or that PMTUD was demonstrably broken on the path. No badge = no definitive evidence either way (most echo-blocked targets fall here).