AS overview
Test target: 2a07:ff00::1 · (no live host found) · address space: PA · prefixes announced: 1
prefix(es): 2a07:ff00::/29
RPKI & ASPA
1 of 1 prefix(es) covered by a valid ROA.
| Prefix | RPKI state | Reason | Covering VRP(s) |
|---|---|---|---|
2a07:ff00::/29 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS204958 /29 maxLen 29 (ripe) |
Random-IP probe (yarrp) into the AS' prefixes
We probed 15 arbitrary IPv6 address(es) inside AS204958's announced prefix(es). No router inside the prefix responded. The deepest visible hop was fd01::2 at hop 17 - that router does not answer ICMPv6 Echo. This is not in AS204958'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 2026-05-25T12:34:54Z
Failure detail — what to grep in your logs
| vantage | our source | your target | method | result | tested (UTC) |
|---|---|---|---|---|---|
| go6lab | 2a00:8642:42::75 | 2a07:ff00::1 | icmp6-echo | no_echo | 2026-05-25T12:34:54Z |
| karsolink | 2a12:d8c0:105a:9001::a154 | 2a07:ff00::1 | icmp6-echo | no_echo | 2026-05-25T12:44:51Z |
| odin | 2607:fae0:a000::42 | 2a07:ff00::1 | icmp6-echo | no_echo | 2026-05-25T12:34:30Z |
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: 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: [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: no path · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | 2a00:8642:42::3 | 1.6ms | 0% | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 2 | gw.friends.steffann.nl 2a00:8642:1000:f000::1 | 2.4ms | 0%* | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 3 | 2a00:1ca8:1::194 | 1.6ms | 0% | AS50673 | Serverius-as - Serverius Holding B.V., NL |
| 4 | 2a03:3f40::10:33 | 5.0ms | 0% | AS50673 | Serverius-as - Serverius Holding B.V., NL |
| 5 | 2001:7f8:1::a501:2874:1 | 21.8ms | 30% | - | NA |
| 6 | 2001:b00:1:1:3::13b | 21.0ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 7 | 2001:b00:1:1:1::1c5 | 21.9ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 8 | 2001:b01:2400:7::2 | 21.2ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 9 | fd01::2 | 38.0ms | - | - | NA |
| 10 | fd01::2 | 1155.6ms | - | - | NA |
Rate-limited ICMPv6: hop 5, hop 11 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.035ms pmtu 1500
1: 2a00:8642:42::3 1.542ms
1: 2a00:8642:42::3 1.408ms
2: gw.friends.steffann.nl 2.615ms
3: 2a00:1ca8:1::194 3.067ms
4: 2a03:3f40::10:33 4.903ms
5: 2001:7f8:1::a501:2874:1 23.246ms
6: 2001:b00:1:1:3::139 22.500ms
7: 2001:b00:1:1:1::1c3 22.308ms
8: 2001:b01:2400:7::2 22.217ms
9: fd01::2 38.309ms
10: fd01::2 1768.540ms !H
Resume: pmtu 1500 From ITA host (Karsolink) transit only unreachable
filter likely at: past AS12874 (FASTWEB) · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | * | - | - | - | |
| 2 | * | - | - | - | |
| 3 | 2a12:d8c0:101f:6::1 | 9.9ms | 0% | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 4 | fastweb.minap.it 2001:7f8:c5::a501:2874:1 | 11.1ms | 40% | AS12874 | Fastweb S.p.A. |
| 5 | 2001:b00:1:1:1::1a9 | 9.7ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 6 | 2001:b00:1:1:1::1c3 | 10.4ms | 20% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 7 | 2001:b01:2400:7::2 | 10.0ms | 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 4, hop 6 (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 0.664ms
2: 2a12:d8c0:109f:121::a1 0.794ms
3: 2a12:d8c0:101f:6::1 10.381ms
4: no reply
5: 2001:b00:1:1:1::1a9 10.256ms
6: 2001:b00:1:1:1::1c5 10.856ms
7: 2001:b01:2400:7::2 10.430ms
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: no path · min PMTU on path: 1500
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 | * | - | - | - | |
| 3 | 2a03:a100:0:201:1::1 | 0.7ms | 70% | AS56635 | XENYA - XENYA inzeniring, proizvodnja in trgovina, d.o.o. Ljubljana, SI |
| 4 | 2001:7f8:46:0:1::3303 | 7.8ms | 0% | AS51988 | ARNES-SIX - ARNES, SI |
| 5 | 2001:918:100:74::1 | 8.0ms | 0% | AS3303 | SWISSCOM - Swisscom (Schweiz) AG, CH |
| 6 | * | - | 40% | - | |
| 7 | 2001:b00:1:1:3::13b | 10.3ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 8 | 2001:b00:1:1:1::1c5 | 10.6ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 9 | 2001:b01:2400:7::2 | 10.7ms | 0% | AS12874 | FASTWEB - Fastweb SpA, IT |
| 10 | fd01::2 | 27.3ms | - | - | NA |
| 11 | fd01::2 | 78.2ms | - | - | NA |
Rate-limited ICMPv6: hop 3, hop 6, hop 12 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.034ms pmtu 1500
1: fw1-lju.6connect.com 0.593ms
1: fw1-lju.6connect.com 0.478ms
2: no reply
3: 2a03:a100:0:201:1::1 1.378ms
4: 2001:7f8:46:0:1::3303 8.034ms
5: 2001:918:100:74::1 8.010ms
6: no reply
7: 2001:b00:1:1:1::1ab 10.171ms asymm 9
8: 2001:b00:1:1:1::1c3 10.986ms asymm 10
9: 2001:b01:2400:7::2 10.755ms asymm 11
10: fd01::2 27.650ms asymm 12
11: no reply
11: fd01::2 3128.941ms !H
Resume: pmtu 1500