AS overview
Test target: 2a05:6680::1 · (no live host found) · address space: PA · prefixes announced: 1
prefix(es): 2a05:6680::/29
RPKI & ASPA
1 of 1 prefix(es) covered by a valid ROA.
| Prefix | RPKI state | Reason | Covering VRP(s) |
|---|---|---|---|
2a05:6680::/29 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS43648 /29 maxLen 32 (ripe) |
Random-IP probe (yarrp) into the AS' prefixes
At least one router inside AS43648's announced prefix replied during the random-target probe. Hop(s): 2a05:6680::. These are candidate targets for direct testing.
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 2026-05-25T12:33:19Z
Failure detail — what to grep in your logs
| vantage | our source | your target | method | result | tested (UTC) |
|---|---|---|---|---|---|
| go6lab | 2a00:8642:42::75 | 2a05:6680::1 | icmp6-echo | no_echo | 2026-05-25T12:33:19Z |
| karsolink | 2a12:d8c0:105a:9001::a154 | 2a05:6680::1 | icmp6-echo | no_echo | 2026-05-25T12:41:35Z |
| odin | 2607:fae0:a000::42 | 2a05:6680::1 | icmp6-echo | no_echo | 2026-05-25T12:33:00Z |
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: no path · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | 2a00:8642:42::3 | 1.1ms | 0% | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 2 | gw.friends.steffann.nl 2a00:8642:1000:f000::1 | 2.3ms | 0%* | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 3 | speed-ix.fibertelecom.it 2001:7f8:b7::a504:1327:1 | 3.5ms | 0% | - | NA |
| 4 | 2a03:b020::228 | 27.0ms | 0% | AS41327 | FIBERTELECOM-AS - Fiber Telecom S.p.A., IT |
| 5 | 2a03:b020:1:31::b | 26.9ms | 0% | AS41327 | FIBERTELECOM-AS - Fiber Telecom S.p.A., IT |
| 6 | 2a05:6680 | 26.7ms | 0% | - | |
| 7 | * | - | - | - | |
| 8 | * | - | - | - | |
| 9 | * | - | - | - | |
| 10 | * | - | - | - | |
| 11 | * | - | - | - | |
| 12 | * | - | - | - | |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | * | - | - | - | |
| 16 | * | - | - | - | |
| 17 | * | - | - | - | |
| 18 | * | - | - | - | |
| 19 | * | - | - | - | |
| 20 | * | - | - | - | |
| 21 | * | - | - | - | |
| 22 | * | - | - | - | |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
tracepath -6
1?: [LOCALHOST] 0.047ms pmtu 1500
1: 2a00:8642:42::3 1.817ms
1: 2a00:8642:42::3 2.018ms
2: gw.friends.steffann.nl 2.279ms
3: speed-ix.fibertelecom.it 4.282ms
4: 2a03:b020::228 27.707ms
5: 2a03:b020:1:31::b 28.170ms
6: 2a05:6680:: 28.210ms
7: no reply
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 ITA host (Karsolink) 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 | karsolink-01.net.karsolink.com 2a12:d8c0:105a:9001::1 | 0.4ms | 0%* | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 2 | 2a12:d8c0:109f:121::a1 | 0.5ms | 0%* | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 3 | * | - | 40% | - | |
| 4 | 2a03:b020:1:51::a | 10.4ms | 0% | AS41327 | FIBERTELECOM-AS - Fiber Telecom S.p.A., IT |
| 5 | 2a03:b020::228 | 18.1ms | 0% | AS41327 | FIBERTELECOM-AS - Fiber Telecom S.p.A., IT |
| 6 | 2a03:b020:1:31::b | 18.7ms | 0% | AS41327 | FIBERTELECOM-AS - Fiber Telecom S.p.A., IT |
| 7 | 2a05:6680 | 18.6ms | 0% | - | |
| 8 | * | - | - | - | |
| 9 | * | - | - | - | |
| 10 | * | - | - | - | |
| 11 | * | - | - | - | |
| 12 | * | - | - | - | |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | * | - | - | - | |
| 16 | * | - | - | - | |
| 17 | * | - | - | - | |
| 18 | * | - | - | - | |
| 19 | * | - | - | - | |
| 20 | * | - | - | - | |
| 21 | * | - | - | - | |
| 22 | * | - | - | - | |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
Rate-limited ICMPv6: hop 3 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.053ms pmtu 1500
1: karsolink-01.net.karsolink.com 0.736ms
1: no reply
2: 2a12:d8c0:109f:121::a1 1.073ms
3: 2a12:d8c0:101f:6::1 10.488ms
4: 2a03:b020:1:51::a 10.676ms
5: 2a03:b020::228 19.437ms
6: 2a03:b020:1:31::b 18.752ms
7: 2a05:6680:: 19.776ms
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 | ccr-to-fw-ccr1-gw-lju.6connect.com 2607:fae0:a000:2::2 | 0.6ms | 0%* | AS8038 | 6CONNECT - 6connect, Inc., US |
| 3 | 2a03:a100:0:201:1::1 | 0.7ms | 80% | AS56635 | XENYA - XENYA inzeniring, proizvodnja in trgovina, d.o.o. Ljubljana, SI |
| 4 | e0-1.core1.lju1.he.net 2001:470:1:5be::1 | 1.9ms | 90% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 5 | * | - | - | - | |
| 6 | port-channel1.core1.zag2.he.net 2001:470:0:2ea::2 | 3.7ms | 90% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 7 | * | - | - | - | |
| 8 | e0-36.core2.rom1.he.net 2001:470:0:4d4::2 | 22.1ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 9 | * | - | - | - | |
| 10 | 2a05:6680 | 18.6ms | 0% | - | |
| 11 | * | - | - | - | |
| 12 | * | - | - | - | |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | * | - | - | - | |
| 16 | * | - | - | - | |
| 17 | * | - | - | - | |
| 18 | * | - | - | - | |
| 19 | * | - | - | - | |
| 20 | * | - | - | - | |
| 21 | * | - | - | - | |
| 22 | * | - | - | - | |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
Rate-limited ICMPv6: hop 3, hop 4, hop 6 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.030ms pmtu 1500
1: fw1-lju.6connect.com 0.439ms
1: fw1-lju.6connect.com 0.474ms
2: no reply
3: no reply
4: e0-1.core1.lju1.he.net 2.083ms
5: no reply
6: port-channel1.core1.zag2.he.net 4.236ms
7: no reply
8: e0-36.core2.rom1.he.net 21.185ms
9: no reply
10: 2a05:6680:: 18.594ms asymm 7
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