State of IPv6 in Italy

Auto-generated narrative from the daily measurement battery.

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This report is about IPv6 only. No measurements, classifications, or conclusions on this page concern IPv4. Legacy IPv4 is not in scope - we do not test it, we do not compare against it, and we do not draw conclusions about its state. Every number, every percentage, every “works / doesn’t work” verdict here refers exclusively to IPv6.

AS inventory

Italy has 1101 autonomous systems visible in the global routing table. Of those, 1068 (97 %) currently announce at least one IPv4 prefix to the global routing table, and 406 (37 %) currently announce at least one IPv6 prefix. That means 38 % of the IPv4-active ASes have followed through and turned on IPv6.

Operators - PA (Provider Aggregatable) holders

PA-holding ASes are LIRs with their own RIR allocation - they are the operators running parts of Italy’s internet (transits, ISPs, content networks with infrastructure of their own). Italy has 906 PA-holding operator ASes registered with the RIR. Of those, 895 (99 %) announce IPv4 today and 323 (36 %) announce IPv6.

906
PA operators (total)
895
PA + IPv4 (99 %)
323
PA + IPv6 (36 %)

End-sites - PI (Provider Independent) holders

PI-holding ASes hold address space directly from the RIR for their own use - typically enterprises, content sites running their own AS for routing diversity, government / academic single-site deployments. They’re not “operators” in the LIR sense, but they show up in BGP and their v6 readiness still matters. Italy has 82 PI-holding end-site ASes. Of those, 80 (98 %) announce IPv4 and 5 (6 %) announce IPv6.

82
PI end-sites (total)
80
PI + IPv4 (98 %)
5
PI + IPv6 (6 %)

Country totals: 1101 routed ASes / 1068 announce IPv4 / 406 announce IPv6. 109 ASes are unclassified (RIPE inet*num lookup didn’t return a clear status). PA / PI counts above include the “mixed” bucket on the PA side since a mixed AS holds at least one PA prefix and operationally functions as an LIR.

Executive summary

We measure how 406 Italian autonomous systems that announce 889 IPv6 prefixes treat ICMPv6 in practice - Echo, Type 2 (Packet Too Big), Time-Exceeded - using eight ICMPv6 vantage points and a 12-node global yarrp mesh, plus the MIX-IT route-server BGP table as ground truth. Generated 2026-09-23 12:33 UTC.

181
ASes classified open
8
ping ok / 1500B fails
5
unreachable / blocked / no host
162
RFC 4890 ✓ proven
26
RFC 4890 ✗ proven
193
ITA ASes peering at MIX-IT

Adoption

According to RIPEstat, 406 ASes registered to Italy announce at least one IPv6 prefix to the global routing table, advertising 889 distinct prefixes between them. The 12-vantage-point mesh observed 303 distinct ASes (Italian + foreign transits) and 655 AS-AS adjacencies along paths into Italy.

ICMPv6 behaviour at the destination

Each AS gets a single classification per vantage point by combining the small Echo, the an unfragmented 1500-byte Echo, traceroute reachability, and a TCP liveness check. Aggregated across all 8 vantage points, the ITA population looks like this:

The open bucket means every vantage point received Echo Replies for both small and 1500-byte probes; this is what every ITA network should look like. echo_only means small ping passed but 1500-byte packets did not - usually either a path-MTU constraint downstream of us, or a real ICMPv6 Type 2 (Packet Too Big) filter en route. The two unreachable buckets cover ASes whose AS edge filters all incoming ICMPv6.

Weekly-probe schedule: 212 of ITA’s 406 IPv6-announcing ASes are on a weekly probe cycle today because they’ve produced a stably-unreachable / no-host result for 14+ consecutive daily runs. Today’s measurements therefore cover the 194 ASes probed this run; the skipped 212 are re-tested weekly. (Tuneable in scripts/19_update_skip_list.py -- raise STREAK_TO_SKIP to probe more aggressively, lower WEEKLY_PROBE_DAYS to re-test sooner.)

RFC 4890 compliance (active Type 2 test)

RFC 4890 gives operators the option to drop ICMPv6 Echo at the firewall, but says Type 2 (Packet Too Big) must remain permitted end-to-end - otherwise PMTUD is broken and large flows hang silently. We test this directly: for every reachable AS we open an active flow (TCP/53 DNS, TCP/443 TLS, ICMPv6 Echo, or HTTP/80 - whichever applies), forge an ICMPv6 Type 2 with MTU=1280, and observe whether the destination acts on it.

Active-test method breakdown across all targets: honored = 2375, no_echo = 1856, not_honored = 513, inconclusive = 46, partial = 2.

MIX-IT peering

The MIX-IT (Milan) currently has 401 peering members reachable via its route servers. Of those, 193 are Italian-registered ASes; the rest are international peers that serve Italian traffic via MIX-IT (common examples: Hurricane Electric, Cloudflare, PCH).

Top MIX-IT-internal transit relationships (BGP-truth)

For the full members list with live route-server session state, see the dedicated MIX-IT page.

Path-MTU and Type 2 evidence

The active Type 2 test produced definitive verdicts for 248 unique destination IP addresses across vantage points.

Global BGP visibility (RIPE RIS)

For every ITA prefix we asked all RIPE RIS collectors what AS-paths they currently see. That gives us each AS' direct upstream(s) according to the global BGP table.

RPKI & ASPA

RPKI ROAs cryptographically bind a prefix to its origin AS, so origin hijacks of that prefix can be filtered. (Route leaks, where the origin is legitimate but the AS path is not, are what ASPA below addresses.) We validate every announced ITA IPv6 prefix against the local Routinator (rpki-lju.6connect.com).

Of 406 ITA ASes announcing IPv6:

Per prefix: 767 valid, 19 invalid, 103 not-found (of 889 total).

RPKI-invalid prefixes

Top unsigned ASes (no ROAs)

ASPA (Autonomous System Provider Authorization)

ASPA is a much newer RPKI object (still an IETF SIDROPS draft, not yet a ratified RFC): it lets a customer AS list which upstream providers may legitimately propagate routes from it. Routes from that AS arriving via any other path are then ASPA-invalid.

51 of 406 ITA ASes have published an ASPA record:

Path asymmetry

For every ITA AS we compared where our outgoing traffic enters their network (the AS just upstream of them on traceroute paths from any of our 8 ICMPv6 vantage points or the 12-node yarrp mesh, 20 sources in total) to which AS the global BGP table says is their direct upstream (RIS view). When these disagree, the network is usually multi-homed and traffic in and out takes different paths - normal in well-peered networks but worth surfacing.

170 ITA ASes flagged as asymmetric this run. Most asymmetric examples (low symmetry score):

Bottom line

This report is regenerated daily at 12:00 Europe/Rome from data/analyzed.json, data/six_lg.json, data/global_topology.json, data/ris_bgp.json, data/asymmetry.json and data/type2_results_<vantage>.json. The text is deterministic - no manual editorial pass.