IPv6 prefix announced, but nothing inside is responding yet. AS43364 announces 1 IPv6 prefix(es) to the global routing table - that’s the part that BGP and our route-server scrape confirm. But our active discovery (curated hostnames, holder-derived domains, authoritative DNS NS/SOA/MX, certificate-transparency hostnames, RIPE Atlas, RDAP, IPv6 Hitlist) found no ICMPv6-responsive host inside the prefix on either vantage, and a yarrp pass against random addresses inside the prefix produced zero in-prefix hops (no router on the path through the AS replied with Time-Exceeded for any random target). That combination usually means the announcement is configured but the addresses inside aren’t in active use yet. The BGP route is there; the operational deployment is still ahead.
AS overview
Test target: 2a0f:d80::1 · (no live host found) · address space: unknown · prefixes announced: 1
prefix(es): 2a0f:d80::/32
MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO peering
MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO member - Selective peering, peering member, since 2022-06-06. IPv6 LAN: 2001:7f8:b:100:1d1:a5d4:3364:73. Locations: -.
RPKI & ASPA
0 of 1 prefix(es) covered by a valid ROA, 1 not-found.
| Prefix | RPKI state | Reason | Covering VRP(s) |
|---|---|---|---|
2a0f:d80::/32 | - not-found | no covering VRP |
Random-IP probe (yarrp) into the AS' prefixes
We probed 15 arbitrary IPv6 address(es) inside AS43364's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a01:20f1:700a::9 at hop 27 - that router answers ICMPv6 Echo. This is not in AS43364's announced prefix; operationally it's the AS-edge / peering interface (often on an IXP peering address or an upstream's /127 link). The traceroute boundary is the AS edge: ICMPv6 Time-Exceeded responses from anything inside this AS are filtered.
ICMPv6 Type 2 (Packet Too Big) acceptance - active test
Type 2 active test inconclusive: no Echo Reply to 1300-byte probe.
method: ICMPv6 Echo + forged PTB, tested 2026-05-25T12:37:29Z
Failure detail — what to grep in your logs
| vantage | our source | your target | method | result | tested (UTC) |
|---|---|---|---|---|---|
| go6lab | 2a00:8642:42::75 | 2a0f:d80::1 | icmp6-echo | no_echo | 2026-05-25T12:37:29Z |
| karsolink | 2a12:d8c0:105a:9001::a154 | 2a0f:d80::1 | icmp6-echo | no_echo | 2026-05-25T12:48:39Z |
| odin | 2607:fae0:a000::42 | 2a0f:d80::1 | icmp6-echo | no_echo | 2026-05-25T12:37:01Z |
Attempt log (go6lab):
icmp6-echo→ no_echo: no Echo Reply to 1300-byte probedns-tcp→ no_tcp: connect failed: [Errno 113] No route to hosttls→ no_tcp: TLS connect failedhttp→ no_tcp: tcp/80 not open
Attempt log (karsolink):
icmp6-echo→ no_echo: no Echo Reply to 1300-byte probedns-tcp→ no_tcp: connect failed: [Errno 113] No route to hosttls→ no_tcp: TLS connect failedhttp→ no_tcp: tcp/80 not open
Attempt log (odin):
icmp6-echo→ no_echo: no Echo Reply to 1300-byte probedns-tcp→ no_tcp: connect failed: [Errno 113] No route to hosttls→ no_tcp: TLS connect failedhttp→ no_tcp: tcp/80 not open
To match the corresponding ICMPv6 packet on your side (host firewall, AS edge, or transit tap), look for our PTBs around the timestamps above:
sudo tcpdump -i any -n -e 'icmp6 and ip6[40] = 2 and (src host 2607:fae0:a000::42 or src host 2a00:8642:42::75 or src host 2a12:d8c0:105a:9001::a154)'
If you see our PTBs arriving but the destination's TCP/Echo flow does not shrink, the drop is in the destination kernel (cause 3 below). If you don't see them at all, drop is upstream of you (cause 2). If you only see them from one of our two source IPs, the drop is path-asymmetric — one transit on the asymmetric route is filtering, the other is not.
From NL host (go6lab) transit only unreachable
filter likely at: past AS3269 (ASN-IBSNAZ) · min PMTU on path: 1500
0/4
Echo small (56B) -
0/4
Echo 1500B (DF) -
no
Type 1 dest-unreach
-
TCP responds on
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | 2a00:8642:42::3 | 1.1ms | 0% | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 2 | gw.friends.steffann.nl 2a00:8642:1000:f000::1 | 2.0ms | 0%* | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 3 | 2a00:1ca8:1::194 | 2.9ms | 0% | AS50673 | Serverius-as - Serverius Holding B.V., NL |
| 4 | 2a03:3f40::10:41 | 2.4ms | 0% | AS50673 | Serverius-as - Serverius Holding B.V., NL |
| 5 | * | - | - | - | |
| 6 | * | - | - | - | |
| 7 | be3500.rcr22.ams05.atlas.cogentco.com 2001:550:0:1000::9a36:3c1a | 5.6ms | 0% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 8 | 2001:978:3::a6 | 10.5ms | 0% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 9 | mil7-loop0-v6.mil.seabone.net 2001:41a8:20::7 | 22.5ms | 0% | AS6762 | SEABONE-NET - TELECOM ITALIA SPARKLE S.p.A., IT |
| 10 | 2001:41a8:20:2::27a | 32.5ms | 20% | AS6762 | SEABONE-NET - TELECOM ITALIA SPARKLE S.p.A., IT |
| 11 | 2a01:20f0:1000::25 | 49.4ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 12 | * | - | - | - | |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | 2a01:20f1:7000::c | 44.9ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 16 | 2a01:20f1:700a::a | 41.7ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 17 | 2a01:20f1:700a::9 | 36.8ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 18 | 2a01:20f1:700a::a | 42.1ms | 90% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 19 | 2a01:20f1:700a::9 | 36.7ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 20 | 2a01:20f1:700a::a | 38.6ms | 90% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 21 | 2a01:20f1:700a::9 | 42.9ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 22 | 2a01:20f1:700a::a | 40.2ms | 90% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 23 | 2a01:20f1:700a::9 | 51.5ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 24 | 2a01:20f1:700a::a | 39.8ms | - | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
Rate-limited ICMPv6: hop 10, hop 18, hop 20, hop 22 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.043ms pmtu 1500
1: 2a00:8642:42::3 1.795ms
1: 2a00:8642:42::3 2.638ms
2: no reply
3: 2a00:1ca8:1::194 3.889ms
4: 2a03:3f40::10:41 3.042ms
5: no reply
6: no reply
7: no reply
8: 2001:978:3::a6 10.843ms asymm 9
9: mil7-loop0-v6.mil.seabone.net 22.735ms asymm 8
10: 2001:41a8:20:2::27a 29.291ms asymm 9
11: ??? 49.079ms asymm 15
12: no reply
13: no reply
14: no reply
15: ??? 46.449ms asymm 14
16: ??? 44.522ms asymm 15
17: ??? 39.883ms asymm 14
18: ??? 42.210ms asymm 15
19: ??? 48.263ms asymm 14
20: ??? 39.266ms asymm 15
21: ??? 40.180ms asymm 14
22: ??? 39.787ms asymm 15
23: ??? 40.737ms asymm 14
24: ??? 38.477ms asymm 15
Too many hops: pmtu 1500
Resume: pmtu 1500 From ITA host (Karsolink) transit only unreachable
filter likely at: past AS3269 (ASN-IBSNAZ) · min PMTU on path: 1500
0/4
Echo small (56B) -
0/4
Echo 1500B (DF) -
no
Type 1 dest-unreach
-
TCP responds on
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | * | - | 0%* | - | |
| 2 | * | - | - | - | |
| 3 | * | - | 40% | - | |
| 4 | 2a03:b020:1:51::a | 10.3ms | 0% | AS41327 | FIBERTELECOM-AS - Fiber Telecom S.p.A., IT |
| 5 | 2001:41a8:20:2::35 | 10.5ms | 0% | AS6762 | SEABONE-NET - TELECOM ITALIA SPARKLE S.p.A., IT |
| 6 | mil51-loop0-v6.mil.seabone.net 2001:41a8:20::33 | 10.8ms | 0% | AS6762 | SEABONE-NET - TELECOM ITALIA SPARKLE S.p.A., IT |
| 7 | 2001:41a8:20:2::412 | 12.0ms | 0% | AS6762 | SEABONE-NET - TELECOM ITALIA SPARKLE S.p.A., IT |
| 8 | 2a01:20f0:1000::25 | 36.9ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 9 | * | - | - | - | |
| 10 | * | - | - | - | |
| 11 | * | - | - | - | |
| 12 | 2a01:20f1:7000::c | 28.1ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 13 | 2a01:20f1:700a::a | 31.2ms | 90% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 14 | 2a01:20f1:700a::9 | 30.4ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 15 | 2a01:20f1:700a::a | 33.6ms | 50% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 16 | 2a01:20f1:700a::9 | 30.4ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 17 | 2a01:20f1:700a::a | 31.7ms | 40% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 18 | 2a01:20f1:700a::9 | 30.5ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 19 | * | - | 90% | - | |
| 20 | 2a01:20f1:700a::9 | 29.3ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 21 | * | - | 90% | - | |
| 22 | 2a01:20f1:700a::9 | 36.8ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 23 | 2a01:20f1:700a::a | 31.9ms | - | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 24 | 2a01:20f1:700a::9 | 29.4ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
Rate-limited ICMPv6: hop 3, hop 13, hop 15, hop 17, hop 19, hop 21 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.026ms pmtu 1500
1: no reply
2: 2a12:d8c0:109f:121::a1 1.079ms
3: no reply
4: 2a03:b020:1:51::a 10.854ms
5: 2001:41a8:20:2::35 11.390ms
6: mil51-loop0-v6.mil.seabone.net 11.114ms
7: 2001:41a8:20:2::27a 12.381ms
8: ??? 33.009ms asymm 14
9: no reply
10: no reply
11: no reply
12: ??? 28.800ms asymm 13
13: ??? 31.580ms asymm 14
14: ??? 28.170ms asymm 12
15: ??? 33.038ms asymm 14
16: ??? 28.246ms asymm 12
17: ??? 32.393ms asymm 14
18: ??? 28.752ms asymm 12
19: ??? 31.703ms asymm 14
20: ??? 28.769ms asymm 12
21: ??? 33.899ms asymm 14
22: ??? 29.862ms asymm 12
23: ??? 32.438ms asymm 14
24: ??? 29.166ms asymm 12
Too many hops: pmtu 1500
Resume: pmtu 1500 From SLO host (6connect) transit only unreachable
filter likely at: past AS3269 (ASN-IBSNAZ) · min PMTU on path: 1500
0/4
Echo small (56B) -
0/4
Echo 1500B (DF) -
no
Type 1 dest-unreach
-
TCP responds on
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | fw1-lju.6connect.com 2607:fae0:a000::2 | 0.4ms | 0%* | AS8038 | 6CONNECT - 6connect, Inc., US |
| 2 | * | - | - | - | |
| 3 | 2a00:ee1:800:9::1 | 1.8ms | 30% | AS5603 | SIOL-NET - Telekom Slovenije, d.d., SI |
| 4 | 2a00:ee0:1:15::2 | 1.0ms | 0% | AS5603 | SIOL-NET - Telekom Slovenije, d.d., SI |
| 5 | 2001:41a8:20:2::169 | 22.8ms | 0% | AS6762 | SEABONE-NET - TELECOM ITALIA SPARKLE S.p.A., IT |
| 6 | mil7-loop0-v6.mil.seabone.net 2001:41a8:20::7 | 8.9ms | 0% | AS6762 | SEABONE-NET - TELECOM ITALIA SPARKLE S.p.A., IT |
| 7 | 2001:41a8:20:2::412 | 9.6ms | 40% | AS6762 | SEABONE-NET - TELECOM ITALIA SPARKLE S.p.A., IT |
| 8 | 2a01:20f2:9000::2c | 29.4ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 9 | * | - | - | - | |
| 10 | * | - | - | - | |
| 11 | * | - | - | - | |
| 12 | 2a01:20f1:7000::c | 29.0ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 13 | 2a01:20f1:700a::a | 27.5ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 14 | 2a01:20f1:700a::9 | 28.6ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 15 | 2a01:20f1:700a::a | 27.5ms | - | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 16 | 2a01:20f1:700a::9 | 28.4ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 17 | 2a01:20f1:700a::a | 31.4ms | 90% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 18 | 2a01:20f1:700a::9 | 29.8ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 19 | 2a01:20f1:700a::a | 28.6ms | - | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 20 | 2a01:20f1:700a::9 | 32.2ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 21 | 2a01:20f1:700a::a | 29.8ms | - | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 22 | 2a01:20f1:700a::9 | 29.8ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 23 | 2a01:20f1:700a::a | 29.1ms | - | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
| 24 | 2a01:20f1:700a::9 | 29.3ms | 0% | AS3269 | ASN-IBSNAZ - Telecom Italia S.p.A., IT |
Rate-limited ICMPv6: hop 3, hop 7, hop 17 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.027ms pmtu 1500
1: fw1-lju.6connect.com 0.481ms
1: fw1-lju.6connect.com 0.522ms
2: no reply
3: 2a00:ee1:800:9::1 2.041ms
4: 2a00:ee0:1:10::2 1.377ms asymm 3
5: 2001:41a8:20:2::169 8.944ms asymm 6
6: mil7-loop0-v6.mil.seabone.net 8.928ms asymm 5
7: 2001:41a8:20:2::27a 9.706ms
8: ??? 27.880ms asymm 13
9: no reply
10: no reply
11: no reply
12: ??? 28.595ms
13: ??? 28.161ms asymm 12
14: ??? 28.891ms asymm 11
15: ??? 28.265ms asymm 12
16: ??? 31.633ms asymm 11
17: ??? 31.219ms asymm 12
18: ??? 28.897ms asymm 11
19: ??? 27.919ms asymm 12
20: ??? 29.079ms asymm 11
21: ??? 28.379ms asymm 12
22: ??? 29.841ms asymm 11
23: ??? 30.531ms asymm 12
24: ??? 31.085ms asymm 11
Too many hops: pmtu 1500
Resume: pmtu 1500