AS overview
Test target: 2a0a:ec04::199 · dns.muscope.com · address space: unknown · prefixes announced: 12
prefix(es): 2a0f:2a04::/32, 2a0a:ec02:201::/48, 2a0a:ec02:501::/48, 2a0a:ec02:401::/48, 2a0a:ec02:101::/48, 2a0a:ec04::/32, 2a0a:ec02:701::/48, 2a0a:ec02:202::/48 (+4 more)
Targets & per-vantage-point probe results (2 target(s) across 3 vantage point(s))
Source codes (hover any badge for full description): CUR=curated · NS/SOA/MX=DNS records · SPF=SPF TXT · DRV=holder-derived (www, ns1, mail, gw, …) · ATL=RIPE Atlas · PDB=PeeringDB · WHOIS=RIPE whois · RDAP=RIPE RDAP · HIT=IPv6 Hitlist · RTR=in-prefix path hop (router) · PRB=static prefix probe · SYN=synthetic prefix::1 fallback
| Target IP / hostname | Source | NL host (go6lab) | ITA host (Karsolink) | SLO host (6connect) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ping | 1500B | :80 | :443 | reached | ping | 1500B | :80 | :443 | reached | ping | 1500B | :80 | :443 | reached | ||
2a0a:ec04::199dns.muscope.com | drv | ✓ | ✓ | open | open | - | ✓ | ✓ | open | open | - | ✓ | ✓ | open | open | - |
2a0a:ec04::210muscope.org | drv | ✓ | ✓ | open | open | - | ✓ | ✓ | open | open | - | ✓ | ✓ | open | open | - |
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 - Open peering, peering member, since 2019-12-18. IPv6 LAN: 2001:7f8:b:100:1d1:a5d4:2692:7. Locations: -.
RPKI & ASPA
12 of 12 prefix(es) covered by a valid ROA.
| Prefix | RPKI state | Reason | Covering VRP(s) |
|---|---|---|---|
2a0f:2a04::/32 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /32 maxLen 32 (ripe) |
2a0a:ec02:201::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec02:501::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec02:401::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec02:101::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec04::/32 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /32 maxLen 32 (ripe) |
2a0a:ec02:701::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec02:202::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec02:902::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec02:ff00::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec02:301::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
2a0a:ec02:a01::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS42692 /48 maxLen 48 (ripe) |
Random-IP probe (yarrp) into the AS' prefixes
We probed 30 arbitrary IPv6 address(es) inside AS42692's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a05:f480:1000:1002::33 at hop 15 - that router answers ICMPv6 Echo. This is not in AS42692'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 honored. Forged ICMPv6 PTB (MTU=1280) was accepted by the destination's stack: the next 1500-byte Echo Reply arrived split into 2 fragments via the IPv6 Fragment Header.
method: ICMPv6 Echo + forged PTB, tested 2026-05-30T12:46:41Z
Where the path divergence is
Per-vantage probe + verdict (headline):
- go6lab: probe
icmp6-echo→ verdicthonored - karsolink: probe
icmp6-echo→ verdicthonored - odin: probe
icmp6-echo→ verdicthonored
Full per-method matrix (all four methods run at each vantage):
| vantage | icmp6-echo | dns-tcp | tls | http |
|---|---|---|---|---|
| go6lab | honored | no_tcp | inconclusive | partial |
| karsolink | honored | no_tcp | not_honored | partial |
| odin | honored | no_tcp | partial | not_honored |
✓ All vantages agree on method(s): icmp6-echo — the headline-method spread above is dispatcher noise, not a real Type 2 disagreement.
These vantage-level disagreements are rooted somewhere in the forward paths. Joining each per-vantage traceroute against the IP→AS lookup from our global yarrp mesh, the first hop where the paths land in different ASes is the most likely site of the offending filter / unreachable AS / Type 2 drop.
Suspect transit ASes (ranked by how often they appear at the divergence point on the path of the worse-classifying vantage): AS20473, AS5405, AS6939.
- From go6lab (open/Type-2=honored) the path enters an opaque hop at hop 20; from karsolink (open/Type-2=honored) the same hop is in AS20473. Last common AS: AS20473. The disagreement is most likely rooted in one of those two transit ASes.
- From go6lab (open/Type-2=honored) the path enters AS20473 at hop 7; from odin (open/Type-2=honored) the same hop is in AS5405. Last common AS: AS20473. The disagreement is most likely rooted in one of those two transit ASes.
- From karsolink (open/Type-2=honored) the path enters AS6939 at hop 8; from odin (open/Type-2=honored) the same hop is in AS5405. Last common AS: AS20473. The disagreement is most likely rooted in one of those two transit ASes.
Diagnosis is path-level, not packet-level: it tells you which transit AS is the prime suspect, not exactly which firewall rule is to blame. Use the tracepath6 output below (when available) for per-hop PMTU evidence on the same path.
✨ Diagnostic interpretation
Per-hop PTB acceptance walk
From the local vantage, we walk the forward path hop-by-hop, sending each hop a 1500-byte ICMPv6 Echo, then a forged PTB (MTU=1280) sourced from us, then another 1500-byte Echo. If the second reply arrives fragmented or smaller, that hop honoured the PTB. If unchanged, it didn't. The first ✗ in an otherwise-✓ path is the most likely filter location. Cross-country aggregation: see the global PTB filter atlas for transit ASes ranked by filter rate across all measurements.
First break at hop 4: AS5603 (SIOL-NET - Telekom Slovenije, d.d., SI) -- this is the most likely site of the offending PTB filter. Hop IP: 2a00:ee0:1:10::2.
| # | hop IP | AS | Holder | PTB acceptance |
|---|---|---|---|---|
| 1 | 2607:fae0:a000::2 | AS8038 | 6CONNECT - 6connect, Inc., US | - skipped (CoPP) |
| 2 | * | - | - (no IP) | |
| 3 | * | - | - (no IP) | |
| 4 | 2a00:ee0:1:10::2 | AS5603 | SIOL-NET - Telekom Slovenije, d.d., SI | ✗ not_honored |
| 5 | 2a11:4142:2002 | - | - (invalid IP) | |
| 6 | 2a11:4140::1e | AS5405 | INTERDOTLINK - Inter.link GmbH, DE | ✓ honored |
| 7 | 2a11:4140::42 | AS5405 | INTERDOTLINK - Inter.link GmbH, DE | ✓ honored |
| 8 | 2a11:4140::4b | AS5405 | INTERDOTLINK - Inter.link GmbH, DE | ✓ honored |
| 9 | 2a11:4140::13 | AS5405 | INTERDOTLINK - Inter.link GmbH, DE | ✓ honored |
| 10 | 2620:107:4008:133b::2 | - | NA | ? no_response |
| 11 | 2001:7f8:4::4ff9:1 | - | NA | ? no_response |
| 12 | * | - | - (no IP) | |
| 13 | 2001:19f0:fc00::a45:419 | - | NA | ? no_response |
| 14 | 2001:19f0:fc00::a45:c2 | - | NA | ? no_response |
| 15 | 2a05:f480:1000:1002::33 | AS20473 | AS-VULTR - The Constant Company, LLC, US | ✗ not_honored |
| 16 | * | - | - (no IP) | |
| 17 | * | - | - (no IP) | |
| 18 | * | - | - (no IP) | |
| 19 | * | - | - (no IP) | |
| 20 | * | - | - (no IP) | |
| 21 | * | - | - (no IP) | |
| 22 | * | - | - (no IP) | |
| 23 | * | - | - (no IP) | |
| 24 | * | - | - (no IP) |
Tests host-mode PTB acceptance (PTBs aimed at the hop itself). A router that honours PTBs to itself can still be filtering PTBs transiting through it; this is one indicator, not proof of full PTB transparency. Hops in CoPP-rate-limit ranges are skipped to avoid false signals.
From NL host (go6lab) openRFC 4890 ✓
filter likely at: (none) · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | 2a00:8642:42::3 | 1.4ms | 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 | ccr2-ccr1.dc1.nogalliance.org 2a00:8642:dc1:2::b | 2.1ms | 0% | AS203993 | STEFFANN-DC-AS - S.J.M. Steffann, NL |
| 4 | 2001:7f8:1::a502:473:1 | 6.0ms | 0% | - | NA |
| 5 | ethernetae1-sr2.ams1.constant.com 2001:19f0:fc00::a48:40a | 5.2ms | 0% | - | NA |
| 6 | ethernetswp55-ds1-u2-r060714-a.ams1.constant.com 2001:19f0:fc00::a48:1f2 | 4.5ms | 0% | - | NA |
| 7 | 2001:19f0:5000:344::33 | 4.6ms | 0% | AS20473 | AS-VULTR - The Constant Company, LLC, US |
| 8 | * | - | 0% | - | |
| 9 | * | - | - | - | |
| 10 | * | - | - | - | |
| 11 | * | - | - | - | |
| 12 | * | - | - | - | |
| 13 | * | - | - | - | |
| 14 | * | - | - | - | |
| 15 | * | - | - | - | |
| 16 | * | - | - | - | |
| 17 | * | - | - | - | |
| 18 | * | - | - | - | |
| 19 | * | - | - | - | |
| 20 | * | - | - | - | |
| 21 | * | - | - | - | |
| 22 | * | - | - | - | |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
tracepath -6
1?: [LOCALHOST] 0.026ms pmtu 1500
1: 2a00:8642:42::3 1.768ms
1: 2a00:8642:42::3 1.481ms
2: gw.friends.steffann.nl 2.347ms
3: ccr2-ccr1.dc1.nogalliance.org 2.400ms asymm 2
4: 2001:7f8:1::a502:473:1 5.342ms asymm 6
5: ethernetae1-sr2.ams1.constant.com 5.582ms asymm 7
6: ethernetswp56-ds1-u2-r060714-a.ams1.constant.com 4.969ms asymm 8
7: 2001:19f0:5000:344::33 6.040ms asymm 8
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) openRFC 4890 ✓
filter likely at: (none) · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | * | - | 0%* | - | |
| 2 | * | - | 0%* | - | |
| 3 | 2a12:d8c0:101f:6::1 | 9.9ms | 10% | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 4 | * | - | - | - | |
| 5 | be3.core2.mrs1.he.net 2001:470:0:2dd::2 | 18.6ms | 40% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 6 | ve952.core1.bio1.he.net 2001:470:0:5c8::2 | 27.8ms | 50% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 7 | * | - | - | - | |
| 8 | be3.core1.atl1.he.net 2001:470:0:637::1 | 108.3ms | 30% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 9 | be1.core2.dal1.he.net 2001:470:e:48::2 | 124.1ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 10 | be3.core2.phx2.he.net 2001:470:e:6c::2 | 140.3ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 11 | be9.core1.lax2.he.net 2001:470:e:6b::1 | 149.0ms | 10% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 12 | * | - | - | - | |
| 13 | singtel-as-ap-as7473.e0-34.core3.lax2.he.net 2001:470:0:4b7::2 | 145.7ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 14 | 2001:c10:80:1::a66 | 344.8ms | 10% | AS7473 | SINGTEL-AS-AP - Singapore Telecommunications Ltd, SG |
| 15 | 2001:c10:80:1::a76 | 329.8ms | 0% | AS7473 | SINGTEL-AS-AP - Singapore Telecommunications Ltd, SG |
| 16 | 2001:c10:80:2::916 | 322.5ms | 10% | AS7473 | SINGTEL-AS-AP - Singapore Telecommunications Ltd, SG |
| 17 | 2001:c10:80:2::f06 | 235.9ms | 0% | AS7473 | SINGTEL-AS-AP - Singapore Telecommunications Ltd, SG |
| 18 | * | - | - | - | |
| 19 | * | - | - | - | |
| 20 | 2001:19f0:4400:80ca::33 | 244.8ms | 0% | AS20473 | AS-VULTR - The Constant Company, LLC, US |
| 21 | * | - | 0% | - | |
| 22 | * | - | - | - | |
| 23 | * | - | - | - | |
| 24 | * | - | - | - |
Rate-limited ICMPv6: hop 3, hop 5, hop 6, hop 8, hop 11, hop 14, hop 16 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.033ms pmtu 1500
1: karsolink-01.net.karsolink.com 0.779ms
2: 2a12:d8c0:109f:121::a1 0.778ms
3: 2a12:d8c0:101f:6::1 10.452ms
4: no reply
5: be3.core2.mrs1.he.net 19.187ms
6: ve952.core1.bio1.he.net 28.426ms
7: no reply
8: be3.core1.atl1.he.net 108.369ms
9: be1.core2.dal1.he.net 123.198ms
10: be3.core2.phx2.he.net 140.809ms
11: be9.core1.lax2.he.net 148.154ms
12: no reply
13: singtel-as-ap-as7473.e0-34.core3.lax2.he.net 146.051ms
14: 2001:c10:80:1::2a1 313.991ms
15: 2001:c10:80:1::a76 340.611ms
16: 2001:c10:80:2::916 336.325ms
17: 2001:c10:80:2::f06 238.047ms asymm 11
18: no reply
19: no reply
20: 2001:19f0:4400:80ca::33 250.007ms asymm 11
21: no reply
22: no reply
23: no reply
24: no reply
Too many hops: pmtu 1500
Resume: pmtu 1500 From SLO host (6connect) openRFC 4890 ✓
filter likely at: (none) · 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 | 0.4ms | 0%* | AS8038 | 6CONNECT - 6connect, Inc., US |
| 2 | * | - | - | - | |
| 3 | * | - | 70% | - | |
| 4 | 2a00:ee0:1:10::2 | 1.0ms | 0% | AS5603 | SIOL-NET - Telekom Slovenije, d.d., SI |
| 5 | 2a11:4142:2002 | 1.3ms | 0% | - | |
| 6 | r2-vie1-at.as5405.net 2a11:4140::1e | 31.9ms | 0% | AS5405 | INTERDOTLINK - Inter.link GmbH, DE |
| 7 | r5-fra1-de.as5405.net 2a11:4140::42 | 32.0ms | 0% | AS5405 | INTERDOTLINK - Inter.link GmbH, DE |
| 8 | r6-fra1-de.as5405.net 2a11:4140::4b | 31.9ms | 0% | AS5405 | INTERDOTLINK - Inter.link GmbH, DE |
| 9 | r3-lon1-gb.as5405.net 2a11:4140::13 | 31.9ms | 0% | AS5405 | INTERDOTLINK - Inter.link GmbH, DE |
| 10 | 2620:107:4008:133b::2 | 31.9ms | 0% | - | NA |
| 11 | 2001:7f8:4::4ff9:1 | 32.5ms | 0% | - | NA |
| 12 | * | - | - | - | |
| 13 | ethernetae4-sr1.lon3.constant.com 2001:19f0:fc00::a45:419 | 34.1ms | 0% | - | NA |
| 14 | ethernetswp56-ds1-u2-r52b06-a.lon3.constant.com 2001:19f0:fc00::a45:c2 | 33.3ms | 0% | - | NA |
| 15 | 2a05:f480:1000:1002::33 | 33.5ms | 0% | AS20473 | AS-VULTR - The Constant Company, LLC, US |
| 16 | * | - | 0% | - | |
| 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] 0.026ms pmtu 1500
1: fw1-lju.6connect.com 0.603ms
1: fw1-lju.6connect.com 0.514ms
2: no reply
3: no reply
4: 2a00:ee0:1:10::2 1.423ms asymm 3
5: 2a11:4142:2002:: 1.094ms asymm 6
6: r2-vie1-at.as5405.net 32.102ms asymm 15
7: r5-fra1-de.as5405.net 32.268ms asymm 13
8: r6-fra1-de.as5405.net 32.058ms asymm 12
9: r3-lon1-gb.as5405.net 32.064ms asymm 12
10: 2620:107:4008:133b::2 32.754ms
11: 2001:7f8:4::4ff9:1 32.645ms asymm 10
12: no reply
13: ethernetae4-sr1.lon3.constant.com 34.162ms asymm 14
14: ethernetswp53-ds1-u2-r52b06-a.lon3.constant.com 33.452ms
15: 2a05:f480:1000:1001::33 33.436ms
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