IPv6 prefix announced, but nothing inside is responding yet. AS211785 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: 2a10:9ec0::1 · (no live host found) · address space: PA · prefixes announced: 1
prefix(es): 2a10:9ec0::/29
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 - Restrictive peering, peering member, since 2020-01-13. IPv6 LAN: 2001:7f8:b:100:1d1:a521:1785:73. Locations: -.
RPKI & ASPA
1 of 1 prefix(es) covered by a valid ROA.
| Prefix | RPKI state | Reason | Covering VRP(s) |
|---|---|---|---|
2a10:9ec0::/29 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS211785 /29 maxLen 29 (ripe) |
Random-IP probe (yarrp) into the AS' prefixes
We probed 15 arbitrary IPv6 address(es) inside AS211785's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2001:978:2:2a::103:2 at hop 22 - that router does not answer ICMPv6 Echo. This is not in AS211785'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 2026-05-25T12:37:49Z
Failure detail — what to grep in your logs
| vantage | our source | your target | method | result | tested (UTC) |
|---|---|---|---|---|---|
| go6lab | 2a00:8642:42::75 | 2a10:9ec0::1 | icmp6-echo | no_echo | 2026-05-25T12:37:49Z |
| karsolink | 2a12:d8c0:105a:9001::a154 | 2a10:9ec0::1 | icmp6-echo | no_echo | 2026-05-25T12:49:30Z |
| odin | 2607:fae0:a000::42 | 2a10:9ec0::1 | icmp6-echo | no_echo | 2026-05-25T12:37:21Z |
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 AS174 (COGENT-174) · 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 | 2.1ms | 0%* | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 3 | 2a00:1ca8:1::194 | 2.7ms | 0% | AS50673 | Serverius-as - Serverius Holding B.V., NL |
| 4 | 2a03:3f40::10:41 | 2.6ms | 0% | AS50673 | Serverius-as - Serverius Holding B.V., NL |
| 5 | 2001:978:2:40::3:1 | 4.1ms | 40% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 6 | * | - | - | - | |
| 7 | be2950.ccr42.fra05.atlas.cogentco.com 2001:550:0:1000::9a36:482a | 11.5ms | 0% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 8 | * | - | 20% | - | |
| 9 | port-channel5891.ccr91.mil02.atlas.cogentco.com 2001:550:0:1000::9a36:3db5 | 25.8ms | 0% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 10 | be5012.rcr51.b019138-1.mil02.atlas.cogentco.com 2001:550:0:1000::9a36:4bda | 26.1ms | 0% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 11 | te0-0-2-1.nr14.b019138-1.mil02.atlas.cogentco.com 2001:550:0:1000::9a19:c66 | 26.2ms | 90% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 12 | 2001:978:2:2a::103:2 | 26.3ms | 0% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 13 | 2001:978:2:2a::103:1 | 25.9ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 14 | 2001:978:2:2a::103:2 | 25.8ms | 90% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 15 | 2001:978:2:2a::103:1 | 25.6ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 16 | 2001:978:2:2a::103:2 | 25.9ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 17 | 2001:978:2:2a::103:1 | 25.6ms | 10% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 18 | 2001:978:2:2a::103:2 | 26.2ms | 90% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 19 | 2001:978:2:2a::103:1 | 26.1ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 20 | 2001:978:2:2a::103:2 | 26.4ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 21 | 2001:978:2:2a::103:1 | 26.1ms | 90% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 22 | 2001:978:2:2a::103:2 | 26.0ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 23 | 2001:978:2:2a::103:1 | 25.8ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 24 | 2001:978:2:2a::103:2 | 26.1ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
Rate-limited ICMPv6: hop 5, hop 8, hop 11, hop 14, hop 17, hop 18, hop 21 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.038ms pmtu 1500
1: 2a00:8642:42::3 1.884ms
1: 2a00:8642:42::3 1.651ms
2: no reply
3: 2a00:1ca8:1::194 3.458ms
4: 2a03:3f40::10:41 3.806ms
5: no reply
6: be3457.ccr41.ams03.atlas.cogentco.com 5.019ms
7: be2950.ccr42.fra05.atlas.cogentco.com 12.016ms
8: no reply
9: port-channel5892.ccr92.mil02.atlas.cogentco.com 25.688ms
10: be4466.rcr51.b019138-1.mil02.atlas.cogentco.com 26.804ms
11: te0-0-2-1.nr14.b019138-1.mil02.atlas.cogentco.com 27.149ms
12: 2001:978:2:2a::103:2 26.559ms
13: 2001:978:2:2a::103:1 26.602ms asymm 11
14: 2001:978:2:2a::103:2 26.467ms asymm 12
15: 2001:978:2:2a::103:1 26.414ms asymm 11
16: 2001:978:2:2a::103:2 26.344ms asymm 12
17: 2001:978:2:2a::103:1 28.024ms asymm 11
18: 2001:978:2:2a::103:2 26.282ms asymm 12
19: 2001:978:2:2a::103:1 26.629ms asymm 11
20: 2001:978:2:2a::103:2 26.699ms asymm 12
21: 2001:978:2:2a::103:1 26.276ms asymm 11
22: 2001:978:2:2a::103:2 26.697ms asymm 12
23: 2001:978:2:2a::103:1 26.674ms asymm 11
24: 2001:978:2:2a::103:2 26.742ms asymm 12
Too many hops: pmtu 1500
Resume: pmtu 1500 From ITA host (Karsolink) transit only unreachable
filter likely at: no path · 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 | * | - | - | - | |
| 2 | * | - | 0%* | - | |
| 3 | 2a12:d8c0:101f:103::1 | 8.5ms | 10% | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 4 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 8.5ms | 80% | - | NA |
| 5 | * | - | - | - | |
| 6 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 8.5ms | 90% | - | NA |
| 7 | * | - | - | - | |
| 8 | * | - | - | - | |
| 9 | * | - | - | - | |
| 10 | * | - | 90% | - | |
| 11 | * | - | 10% | - | |
| 12 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 8.8ms | - | - | NA |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | * | - | 90% | - | |
| 16 | * | - | - | - | |
| 17 | * | - | - | - | |
| 18 | * | - | 20% | - | |
| 19 | * | - | - | - | |
| 20 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 9.0ms | 89% | - | NA |
| 21 | * | - | - | - | |
| 22 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 8.7ms | - | - | NA |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
Rate-limited ICMPv6: hop 3, hop 4, hop 6, hop 10, hop 11, hop 15, hop 18, hop 20 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.029ms pmtu 1500
1: karsolink-01.net.karsolink.com 0.503ms
2: 2a12:d8c0:109f:121::a1 0.830ms
3: 2a12:d8c0:101f:103::1 8.842ms
4: techlabitalia-v6.mix-it.net 9.098ms
5: 2001:978:2:2a::103:1 11.060ms asymm 11
6: techlabitalia-v6.mix-it.net 36.339ms asymm 4
7: 2001:978:2:2a::103:1 11.055ms asymm 11
8: techlabitalia-v6.mix-it.net 9.304ms asymm 4
9: 2001:978:2:2a::103:1 10.922ms asymm 11
10: techlabitalia-v6.mix-it.net 9.434ms asymm 4
11: 2001:978:2:2a::103:1 11.344ms
12: techlabitalia-v6.mix-it.net 9.410ms asymm 4
13: 2001:978:2:2a::103:1 52.715ms asymm 11
14: techlabitalia-v6.mix-it.net 9.693ms asymm 4
15: 2001:978:2:2a::103:1 11.339ms asymm 11
16: techlabitalia-v6.mix-it.net 9.526ms asymm 4
17: 2001:978:2:2a::103:1 11.487ms asymm 11
18: techlabitalia-v6.mix-it.net 9.618ms asymm 4
19: 2001:978:2:2a::103:1 11.722ms asymm 11
20: techlabitalia-v6.mix-it.net 9.711ms asymm 4
21: 2001:978:2:2a::103:1 11.473ms asymm 11
22: techlabitalia-v6.mix-it.net 9.762ms asymm 4
23: 2001:978:2:2a::103:1 11.428ms asymm 11
24: techlabitalia-v6.mix-it.net 10.013ms asymm 4
Too many hops: pmtu 1500
Resume: pmtu 1500 From SLO host (6connect) transit only unreachable
filter likely at: no path · 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 | 0.3ms | 0%* | AS8038 | 6CONNECT - 6connect, Inc., US |
| 2 | * | - | 0%* | - | |
| 3 | 2a03:a100:0:201:1::1 | 0.6ms | 60% | AS56635 | XENYA - XENYA inzeniring, proizvodnja in trgovina, d.o.o. Ljubljana, SI |
| 4 | e0-1.core1.lju1.he.net 2001:470:1:5be::1 | 1.6ms | 30% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 5 | * | - | - | - | |
| 6 | port-channel1.core1.zag2.he.net 2001:470:0:2ea::2 | 3.9ms | 90% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 7 | * | - | - | - | |
| 8 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.3ms | 0% | - | NA |
| 9 | 2001:978:2:2a::103:1 | 18.6ms | 90% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 10 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.3ms | 90% | - | NA |
| 11 | 2001:978:2:2a::103:1 | 18.5ms | 0% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 12 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.1ms | - | - | NA |
| 13 | 2001:978:2:2a::103:1 | 18.3ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 14 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.2ms | - | - | NA |
| 15 | 2001:978:2:2a::103:1 | 18.3ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 16 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.5ms | - | - | NA |
| 17 | 2001:978:2:2a::103:1 | 18.4ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 18 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.4ms | 90% | - | NA |
| 19 | 2001:978:2:2a::103:1 | 18.7ms | 90% | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 20 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.3ms | - | - | NA |
| 21 | 2001:978:2:2a::103:1 | 18.6ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 22 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.5ms | - | - | NA |
| 23 | 2001:978:2:2a::103:1 | 18.6ms | - | AS174 | COGENT-174 - Cogent Communications, LLC, US |
| 24 | techlabitalia-v6.mix-it.net @MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO 2001:7f8:b:100:1d1:a521:1785:73 | 12.5ms | - | - | NA |
Rate-limited ICMPv6: hop 3, hop 4, hop 6, hop 9, hop 10, hop 18, hop 19 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.029ms pmtu 1500
1: fw1-lju.6connect.com 0.504ms
1: fw1-lju.6connect.com 0.526ms
2: no reply
3: no reply
4: e0-1.core1.lju1.he.net 2.245ms
5: no reply
6: port-channel1.core1.zag2.he.net 4.143ms
7: no reply
8: techlabitalia-v6.mix-it.net 12.318ms
9: 2001:978:2:2a::103:1 18.799ms asymm 10
10: techlabitalia-v6.mix-it.net 12.368ms asymm 8
11: 2001:978:2:2a::103:1 19.714ms asymm 10
12: techlabitalia-v6.mix-it.net 12.647ms asymm 8
13: 2001:978:2:2a::103:1 18.745ms asymm 10
14: techlabitalia-v6.mix-it.net 12.545ms asymm 8
15: 2001:978:2:2a::103:1 18.573ms asymm 10
16: techlabitalia-v6.mix-it.net 12.471ms asymm 8
17: 2001:978:2:2a::103:1 18.675ms asymm 10
18: techlabitalia-v6.mix-it.net 12.477ms asymm 8
19: 2001:978:2:2a::103:1 18.791ms asymm 10
20: techlabitalia-v6.mix-it.net 12.733ms asymm 8
21: 2001:978:2:2a::103:1 19.207ms asymm 10
22: techlabitalia-v6.mix-it.net 12.816ms asymm 8
23: 2001:978:2:2a::103:1 18.850ms asymm 10
24: techlabitalia-v6.mix-it.net 12.706ms asymm 8
Too many hops: pmtu 1500
Resume: pmtu 1500