IPv6 prefix announced, but nothing inside is responding yet. AS207342 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: 2a06:de47::1 · (no live host found) · address space: PA · prefixes announced: 1
prefix(es): 2a06:de47::/32
RPKI & ASPA
1 of 1 prefix(es) covered by a valid ROA.
| Prefix | RPKI state | Reason | Covering VRP(s) |
|---|---|---|---|
2a06:de47::/32 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS207342 /32 maxLen 32 (ripe); AS200858 /29 maxLen 29 (ripe) |
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 2026-05-25T12:34:12Z
Failure detail — what to grep in your logs
| vantage | our source | your target | method | result | tested (UTC) |
|---|---|---|---|---|---|
| go6lab | 2a00:8642:42::75 | 2a06:de47::1 | icmp6-echo | no_echo | 2026-05-25T12:34:12Z |
| karsolink | 2a12:d8c0:105a:9001::a154 | 2a06:de47::1 | icmp6-echo | no_echo | 2026-05-25T12:42:50Z |
| odin | 2607:fae0:a000::42 | 2a06:de47::1 | icmp6-echo | no_echo | 2026-05-25T12:33:50Z |
Attempt log (go6lab):
icmp6-echo→ no_echo: no Echo Reply to 1300-byte probedns-tcp→ no_tcp: connect failed: timed outtls→ 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: timed outtls→ 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: timed outtls→ 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 AS12874 (FASTWEB) · 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 | 1.3ms | 0% | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 2 | gw.friends.steffann.nl 2a00:8642:1000:f000::1 | 1.7ms | 0%* | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 3 | 2a00:1ca8:1::194 | 3.2ms | 0% | AS50673 | Serverius-as - Serverius Holding B.V., NL |
| 4 | 2a03:3f40::10:33 | 5.1ms | 0% | AS50673 | Serverius-as - Serverius Holding B.V., NL |
| 5 | * | - | 30% | - | |
| 6 | 2001:b00:1:1:3::139 | 20.6ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 7 | 2001:b00:1:1:1::1c3 | 21.3ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 8 | 2001:b01:2400:ce::1 | 20.7ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 9 | * | - | - | - | |
| 10 | * | - | - | - | |
| 11 | * | - | - | - | |
| 12 | * | - | - | - | |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | * | - | - | - | |
| 16 | * | - | - | - | |
| 17 | * | - | - | - | |
| 18 | * | - | - | - | |
| 19 | * | - | - | - | |
| 20 | * | - | - | - | |
| 21 | * | - | - | - | |
| 22 | * | - | - | - | |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
Rate-limited ICMPv6: hop 5 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.039ms pmtu 1500
1: 2a00:8642:42::3 1.872ms
1: 2a00:8642:42::3 1.595ms
2: gw.friends.steffann.nl 2.463ms
3: 2a00:1ca8:1::194 3.329ms
4: 2a03:3f40::10:33 5.363ms
5: 2001:7f8:1::a501:2874:1 22.037ms
6: 2001:b00:1:1:3::139 21.920ms
7: 2001:b00:1:1:1::1c3 23.081ms
8: 2001:b01:2400:ce::1 22.792ms
9: no reply
10: no reply
11: no reply
12: no reply
13: no reply
14: no reply
15: no reply
16: no reply
17: no reply
18: no reply
19: no reply
20: no reply
21: no reply
22: no reply
23: no reply
24: no reply
Too many hops: pmtu 1500
Resume: pmtu 1500 From ITA host (Karsolink) transit only unreachable
filter likely at: past AS12874 (FASTWEB) · 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 | karsolink-01.net.karsolink.com 2a12:d8c0:105a:9001::1 | 0.3ms | 0%* | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 2 | 2a12:d8c0:109f:121::a1 | 0.4ms | 0%* | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 3 | 2a12:d8c0:101f:6::1 | 10.0ms | 50% | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 4 | * | - | 30% | - | |
| 5 | 2001:b00:1:1:1::1a9 | 9.7ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 6 | 2001:b00:1:1:1::1c5 | 10.2ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 7 | 2001:b01:2400:ce::1 | 9.7ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 8 | * | - | - | - | |
| 9 | * | - | - | - | |
| 10 | * | - | - | - | |
| 11 | * | - | - | - | |
| 12 | * | - | - | - | |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | * | - | - | - | |
| 16 | * | - | - | - | |
| 17 | * | - | - | - | |
| 18 | * | - | - | - | |
| 19 | * | - | - | - | |
| 20 | * | - | - | - | |
| 21 | * | - | - | - | |
| 22 | * | - | - | - | |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
Rate-limited ICMPv6: hop 3, hop 4 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.044ms pmtu 1500
1: karsolink-01.net.karsolink.com 0.672ms
1: karsolink-01.net.karsolink.com 0.862ms
2: 2a12:d8c0:109f:121::a1 0.766ms
3: 2a12:d8c0:101f:6::1 10.332ms
4: fastweb.minap.it 11.658ms
5: 2001:b00:1:1:1::1a7 10.067ms
6: 2001:b00:1:1:1::1c3 10.949ms
7: 2001:b01:2400:ce::1 10.260ms
8: no reply
9: no reply
10: no reply
11: no reply
12: no reply
13: no reply
14: no reply
15: no reply
16: no reply
17: no reply
18: no reply
19: no reply
20: no reply
21: no reply
22: no reply
23: no reply
24: no reply
Too many hops: pmtu 1500
Resume: pmtu 1500 From SLO host (6connect) transit only unreachable
filter likely at: past AS12874 (FASTWEB) · 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 | ccr-to-fw-ccr1-gw-lju.6connect.com 2607:fae0:a000:2::2 | 0.6ms | - | AS8038 | 6CONNECT - 6connect, Inc., US |
| 3 | 2a00:ee1:800:9::1 | 2.0ms | 80% | AS5603 | SIOL-NET - Telekom Slovenije, d.d., SI |
| 4 | 2a00:ee0:1:15::2 | 1.1ms | 0% | AS5603 | SIOL-NET - Telekom Slovenije, d.d., SI |
| 5 | 2a11:4142:2002 | 1.0ms | 0% | - | |
| 6 | 2620:107:4008:e85::2 | 8.2ms | 0% | - | NA |
| 7 | * | - | 50% | - | |
| 8 | 2001:b00:1:1:3::137 | 10.6ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 9 | 2001:b00:1:1:1::1c5 | 11.2ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 10 | 2001:b01:2400:ce::1 | 10.8ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 11 | * | - | - | - | |
| 12 | * | - | - | - | |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | * | - | - | - | |
| 16 | * | - | - | - | |
| 17 | * | - | - | - | |
| 18 | * | - | - | - | |
| 19 | * | - | - | - | |
| 20 | * | - | - | - | |
| 21 | * | - | - | - | |
| 22 | * | - | - | - | |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
Rate-limited ICMPv6: hop 3, hop 7 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.026ms pmtu 1500
1: fw1-lju.6connect.com 0.492ms
1: fw1-lju.6connect.com 0.342ms
2: ccr-to-fw-ccr1-gw-lju.6connect.com 0.743ms
3: 2a00:ee1:800:9::1 2.142ms
4: 2a00:ee0:1:10::2 1.056ms asymm 3
5: 2a11:4142:2002:: 1.081ms asymm 6
6: 2620:107:4008:e85::2 8.204ms asymm 7
7: no reply
8: 2001:b00:1:1:3::137 10.856ms asymm 9
9: 2001:b00:1:1:1::1c3 11.166ms asymm 10
10: 2001:b01:2400:ce::1 10.659ms asymm 11
11: no reply
12: no reply
13: no reply
14: no reply
15: no reply
16: no reply
17: no reply
18: no reply
19: no reply
20: no reply
21: no reply
22: no reply
23: no reply
24: no reply
Too many hops: pmtu 1500
Resume: pmtu 1500