AS overview
Test target: 2001:7f8:1e:3::166 · ns3.sox.rs · address space: mixed · prefixes announced: 1
prefix(es): 2001:7f8:1e::/48
Targets & per-vantage-point probe results (2 target(s) across 7 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 | SRB host (SOX, Belgrade) | DE host (Berlin) | DE host (Düsseldorf) | NL host (go6lab) | ITA host (Karsolink) | SLO host (6connect) | SLO host (T-2) | ||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ping | 1500B | :80 | :443 | reached | ping | 1500B | :80 | :443 | reached | ping | 1500B | :80 | :443 | reached | ping | 1500B | :80 | :443 | reached | ping | 1500B | :80 | :443 | reached | ping | 1500B | :80 | :443 | reached | ping | 1500B | :80 | :443 | reached | ||
2001:7f8:1e:3::166ns3.sox.rs | NS | ✓ | ✓ | ? | ? | ✓ | ✓ | ✓ | ? | ? | ✓ | ✓ | ✓ | ? | ? | ✓ | ✓ | ✓ | ? | ? | ✓ | ✓ | ✓ | ? | ? | ✓ | ✓ | ✓ | ? | ? | ✓ | ✓ | ✓ | ? | ? | - |
2001:7f8:1e:3::178mailserv.sox.rs | MX | ✓ | ✓ | open | open | ✓ | ✓ | ✓ | open | open | ✓ | ✓ | ✓ | open | open | ✓ | ✓ | ✓ | open | open | ✓ | ✓ | ✓ | open | open | ✓ | ✓ | ✓ | open | open | ✓ | ✓ | ✓ | open | open | ✓ |
SOX peering
SOX member - Open peering, peering member, since 2015-08-20. IPv6 LAN: 2001:7f8:1e::1. Locations: -.
RPKI & ASPA
1 of 1 prefix(es) covered by a valid ROA.
| Prefix | RPKI state | Reason | Covering VRP(s) |
|---|---|---|---|
2001:7f8:1e::/48 | ✓ valid | matched VRP (correct origin, length within maxLength) | AS13004 /48 maxLen 48 (ripe) |
Random-IP probe (yarrp) into the AS' prefixes
We probed 35 arbitrary IPv6 address(es) inside AS13004's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a02:2d8:0:a00e:232a::1 at hop 8 - that router answers ICMPv6 Echo. This is not in AS13004's announced prefix; operationally it's the AS-edge / peering interface (often on a SOX 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 2026-09-23T11:08:31Z
tracepath6 per-hop PMTU drilldown
For each target where Type 2 verdicts disagreed across vantages, tracepath -6 ran from every vantage to capture per-hop PMTU evolution along that vantage's actual forward path. A pmtu change entry on a hop means that hop's router generated a PTB and we observed the shrink; absence of any change combined with a not_honored verdict suggests a router somewhere downstream is silently dropping >MTU packets (an RFC 4890 violation) rather than sending a PTB.
Target 2001:7f8:1e:3::178
amsterdam - verdict ?
(no hops captured)
belgrade - verdict honored
verdict = honored; final pmtu = 1500
| # | hop IP | pmtu change |
|---|---|---|
| 1 | <span class='muted'>no reply</span> | |
| 2 | 2001:7f8:1e::12 | |
| 3 | 2001:7f8:1e:3::178 |
berlin - verdict honored
verdict = honored; final pmtu = 1500
| # | hop IP | pmtu change |
|---|---|---|
| 1 | <span class='muted'>no reply</span> | |
| 2 | 2a06:d1c0::dead:beef:1c02 | |
| 3 | 2001:7f8:19:1::232a:1 | |
| 4 | 2a02:2d8::57f5:e0af | |
| 5 | 2a02:2d8:0:a00e:232a::1 | |
| 6 | 2001:7f8:1e:3::178 |
duseldorf - verdict honored
verdict = honored; final pmtu = 1500
| # | hop IP | pmtu change |
|---|---|---|
| 1 | <span class='muted'>no reply</span> | |
| 2 | 2001:4ba0:92f4:3::1 | |
| 3 | <span class='muted'>no reply</span> | |
| 4 | 2001:4ba0:ffe9:115::3 | |
| 5 | 2001:4ba0:ffe9:4f::1 | |
| 6 | 2001:7f8::232a:0:1 | |
| 7 | 2a02:2d8::57f5:e0af | |
| 8 | 2a02:2d8:0:a00e:232a::1 | |
| 9 | 2001:7f8:1e:3::178 |
go6lab - verdict not_honored
verdict = not_honored; final pmtu = 1500
| # | hop IP | pmtu change |
|---|---|---|
| 1 | <span class='muted'>no reply</span> | |
| 2 | 2a00:8642:1000:f000::1 | |
| 3 | 2a00:8642:dc1:2::b | |
| 4 | 2001:7f8:1::a500:9002:1 | |
| 5 | 2a02:2d8::57f5:e0af | |
| 6 | 2a02:2d8:0:a00e:232a::1 | |
| 7 | 2001:7f8:1e:3::178 |
karsolink - verdict honored
verdict = honored; final pmtu = 1500
| # | hop IP | pmtu change |
|---|---|---|
| 1 | <span class='muted'>no reply</span> | |
| 2 | 2a12:d8c0:109f:121::a1 | |
| 3 | 2a12:d8c0:101f:103::1 | |
| 4 | <span class='muted'>no reply</span> | |
| 5 | 2001:470:0:414::1 | |
| 6 | 2001:470:0:412::2 | |
| 7 | 2001:470:0:33f::1 | |
| 8 | 2001:470:1:6e5::2 | |
| 9 | 2001:7f8:1e:3::178 |
odin - verdict honored
verdict = honored; final pmtu = 1500
| # | hop IP | pmtu change |
|---|---|---|
| 1 | <span class='muted'>no reply</span> | |
| 2 | 2607:fae0:a000:2::2 | |
| 3 | 2a00:ee1:800:9::1 | |
| 4 | 2a00:ee0:1:10::2 | |
| 5 | 2a00:ee0:1:15::2 | |
| 6 | 2a02:2d8::57f5:e0af | |
| 7 | 2a02:2d8:0:a00e:232a::1 | |
| 8 | 2001:7f8:1e:3::178 |
t2 - verdict honored
verdict = honored; final pmtu = 1500
| # | hop IP | pmtu change |
|---|---|---|
| 1 | <span class='muted'>no reply</span> | |
| 2 | 2a01:260:1::225 | |
| 3 | 2a01:260:1:1::9a | |
| 4 | 2a01:260:1:1::38 | |
| 5 | 2001:470:0:4a8::1 | |
| 6 | 2001:470:0:412::2 | |
| 7 | 2001:470:0:412::2 | |
| 8 | 2001:470:0:33f::1 | |
| 9 | 2001:7f8:1e:3::178 |
Multi-vantage path map
Every hop of all vantages’ traceroutes toward the target, drawn left→right, grouped into per-AS bubbles (a hop seen from several vantages is one shared bubble, so converging paths merge). It answers two questions per vantage — shown on each source bubble as echo ✓/⚠/✗ · trace ✓/✗: did the destination reply to ICMPv6 Echo (✓ honored, ⚠ replied but PTB not honored, ✗ no reply), and did the traceroute reach it. A line to the target is drawn only when that vantage got an echo reply — solid if the PTB was honored, dashed if not (reachable but a broken-PMTUD / RFC 4890 violation). The path depth still shows how far the traceroute itself got, and runs of unanswered (* *) hops collapse into one dashed “silent” bubble. Open full size ↗
- ● SRB host (SOX, Belgrade)
- ● DE host (Berlin)
- ● DE host (Düsseldorf)
- ● NL host (go6lab)
- ● ITA host (Karsolink)
- ● SLO host (6connect)
- ● SLO host (T-2)
- ── solid line = echo reply, PTB honored (clean reach)
- — — dashed line = echo reply but PTB not honored (RFC 4890 violation)
- no line = no echo reply (never reached)
- ◉ target: green = clean, amber = reachable-but-violation / unreachable
- ⚠ suspected drop AS
- ⋯ silent (unanswered) hops
- ● IXP hop
From SRB host (SOX, Belgrade) openRFC 4890 ✓
filter likely at: (none) · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | 2a09:ab81::1 | 0.5ms | 0%* | AS60733 | PERKE-NET - ZORAN PEROVIC trading as Agencija Perke.NET, RS |
| 2 | sw-thq-cisco.sox.rs @SOX 2001:7f8:1e::12 | 0.7ms | 0% | AS13004 | Serbian Open eXchange |
| 3 | 2001:7f8:1e:3::166 | 0.5ms | 0% | AS13004 | SOX - Serbian Open Exchange DOO, RS |
tracepath -6
1?: [LOCALHOST] 0.009ms pmtu 1500
1: _gateway 0.785ms
1: _gateway 1.328ms
2: sw-thq-cisco.sox.rs 0.742ms
3: 2001:7f8:1e:3::166 0.702ms !A
Resume: pmtu 1500 From DE host (Berlin) openRFC 4890 ✓
filter likely at: (none) · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | xe-0-0-13-178.gw01.ber01.as59645.net 2a06:d1c1:100:b::1 | 0.2ms | 0%* | AS59645 | WYBT-NET - Tobias Fiebig, DE |
| 2 | ae0-2453.cr10.ber01.lwlcom.net 2a06:d1c0::dead:beef:1c02 | 0.6ms | 0%* | AS59645 | WYBT-NET - Tobias Fiebig, DE |
| 3 | retn.bcix.de 2001:7f8:19:1::232a:1 | 10.4ms | 0% | - | NA |
| 4 | RT.IRX.VIE.AT.retn.net 2a02:2d8::57f5:e0af | 21.4ms | 0% | AS9002 | RETN-AS - RETN Limited, GB |
| 5 | GW-AS13004.retn.net 2a02:2d8:0:a00e:232a::1 | 38.2ms | 0% | AS9002 | RETN-AS - RETN Limited, GB |
| 6 | 2001:7f8:1e:3::166 | 39.5ms | 0% | AS13004 | SOX - Serbian Open Exchange DOO, RS |
tracepath -6
1?: [LOCALHOST] 0.033ms pmtu 1500
1: xe-0-0-13-178.gw01.ber01.as59645.net 0.644ms
1: xe-0-0-13-178.gw01.ber01.as59645.net 0.386ms
2: ae0-2453.cr10.ber01.lwlcom.net 0.875ms
3: retn.bcix.de 10.709ms asymm 5
4: RT.IRX.VIE.AT.retn.net 21.829ms asymm 5
5: GW-AS13004.retn.net 38.412ms asymm 8
6: 2001:7f8:1e:3::166 39.871ms !A
Resume: pmtu 1500 From DE host (Düsseldorf) openRFC 4890 ✓
filter likely at: (none) · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | xe-0-0-12-142.gw01.dus01.as59645.net 2a06:d1c1:100:d::1 | 0.1ms | 0%* | AS59645 | WYBT-NET - Tobias Fiebig, DE |
| 2 | eth1-0-12-h5594.edge5-dus1.bb.wiit.network 2001:4ba0:92f4:3::1 | 7.2ms | 0% | AS24961 | MYLOC-AS - WIIT AG, DE |
| 3 | lag10-h5f01.agr4-dus1.bb.wiit.network 2001:4ba0:ffe9:7c::1 | 40.7ms | 0% | AS24961 | MYLOC-AS - WIIT AG, DE |
| 4 | lag30.core3-dus1.bb.wiit.network 2001:4ba0:ffe9:109::2 | 0.2ms | 0% | AS24961 | MYLOC-AS - WIIT AG, DE |
| 5 | lag8.core1-dus-ix.bb.wiit.network 2001:4ba0:ffe9:8::2 | 0.4ms | 0% | AS24961 | MYLOC-AS - WIIT AG, DE |
| 6 | de-cix1.rt.act.fkt.de.retn.net 2001:7f8::232a:0:1 | 4.2ms | 10% | - | NA |
| 7 | RT.IRX.VIE.AT.retn.net 2a02:2d8::57f5:e0af | 15.6ms | 0% | AS9002 | RETN-AS - RETN Limited, GB |
| 8 | GW-AS13004.retn.net 2a02:2d8:0:a00e:232a::1 | 34.3ms | 0% | AS9002 | RETN-AS - RETN Limited, GB |
| 9 | 2001:7f8:1e:3::166 | 32.3ms | 0% | AS13004 | SOX - Serbian Open Exchange DOO, RS |
Rate-limited ICMPv6: hop 6 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.021ms pmtu 1500
1: xe-0-0-12-142.gw01.dus01.as59645.net 0.363ms
1: xe-0-0-12-142.gw01.dus01.as59645.net 0.279ms
2: eth1-0-12-h5594.edge5-dus1.bb.wiit.network 1.623ms
3: no reply
4: lag30.core3-dus1.bb.wiit.network 0.258ms
5: lag2.core1-dus-ix.bb.wiit.network 0.491ms
6: de-cix1.rt.act.fkt.de.retn.net 4.651ms asymm 4
7: RT.IRX.VIE.AT.retn.net 15.992ms asymm 4
8: GW-AS13004.retn.net 34.790ms asymm 7
9: 2001:7f8:1e:3::166 32.683ms !A
Resume: pmtu 1500 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::2 | 0.3ms | 0% | AS203993 | GNA-DC1-AS - S.J.M. Steffann, NL |
| 2 | gw.friends.steffann.nl 2a00:8642:1000:f000::1 | 1.7ms | 0%* | AS203993 | GNA-DC1-AS - S.J.M. Steffann, NL |
| 3 | ccr2-ccr1.dc1.nogalliance.org 2a00:8642:dc1:2::b | 3.4ms | 0% | AS203993 | GNA-DC1-AS - S.J.M. Steffann, NL |
| 4 | ams-ix.retn.net 2001:7f8:1::a500:9002:1 | 5.2ms | 0% | - | NA |
| 5 | RT.IRX.VIE.AT.retn.net 2a02:2d8::57f5:e0af | 21.9ms | 20% | AS9002 | RETN-AS - RETN Limited, GB |
| 6 | GW-AS13004.retn.net 2a02:2d8:0:a00e:232a::1 | 36.6ms | 0% | AS9002 | RETN-AS - RETN Limited, GB |
| 7 | 2001:7f8:1e:3::166 | 36.3ms | 0% | AS13004 | SOX - Serbian Open Exchange DOO, RS |
Rate-limited ICMPv6: hop 5 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.069ms pmtu 1500
1: 2a00:8642:42::2 3.365ms
1: 2a00:8642:42::2 4.077ms
2: gw.friends.steffann.nl 6.501ms
3: ccr2-ccr1.dc1.nogalliance.org 5.072ms asymm 2
4: ams-ix.retn.net 17.288ms asymm 7
5: RT.IRX.VIE.AT.retn.net 24.522ms asymm 6
6: GW-AS13004.retn.net 38.814ms asymm 7
7: 2001:7f8:1e:3::166 43.203ms !A
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 | 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 | 0.3ms | 0%* | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 3 | 2a12:d8c0:101f:103::1 | 8.4ms | 90% | AS204471 | KARSOLINK - 2S Computers SRL, IT |
| 4 | * | - | - | - | |
| 5 | 100ge0-0-0-20.core1.vie1.he.net 2001:470:0:414::1 | 22.5ms | 10% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 6 | e0-35.core2.bts1.he.net 2001:470:0:412::2 | 21.4ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 7 | e0-36.core2.beg1.he.net 2001:470:0:33f::1 | 28.9ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 8 | serbian-open-exchange-doo.10gigabitethernet1-1-2.switch1.beg1.he.net 2001:470:1:6e5::2 | 26.4ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 9 | 2001:7f8:1e:3::166 | 25.8ms | 0% | AS13004 | SOX - Serbian Open Exchange DOO, RS |
Rate-limited ICMPv6: hop 3, hop 5 (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 0.643ms
2: 2a12:d8c0:109f:121::a1 0.588ms
3: 2a12:d8c0:101f:6::1 10.194ms
4: no reply
5: 100ge0-0-0-20.core1.vie1.he.net 22.168ms
6: e0-35.core2.bts1.he.net 22.488ms
7: e0-36.core2.beg1.he.net 28.804ms
8: serbian-open-exchange-doo.10gigabitethernet1-1-2.switch1.beg1.he.net 26.856ms asymm 7
9: 2001:7f8:1e:3::166 26.901ms !A
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 | 0.2ms | 0%* | AS8038 | 6CONNECT - 6connect, Inc., US |
| 2 | * | - | - | - | |
| 3 | 2a00:ee1:800:9::1 | 1.8ms | 50% | AS5603 | SIOL-NET - Telekom Slovenije, d.d., SI |
| 4 | 2a00:ee0:1:10::2 | 1.0ms | 0% | AS5603 | SIOL-NET - Telekom Slovenije, d.d., SI |
| 5 | de-cix1.rt.act.fkt.de.retn.net 2001:7f8::232a:0:1 | 13.7ms | 0% | - | NA |
| 6 | RT.IRX.VIE.AT.retn.net 2a02:2d8::57f5:e0af | 13.9ms | 0% | AS9002 | RETN-AS - RETN Limited, GB |
| 7 | GW-AS13004.retn.net 2a02:2d8:0:a00e:232a::1 | 48.8ms | 0% | AS9002 | RETN-AS - RETN Limited, GB |
| 8 | 2001:7f8:1e:3::166 | 48.7ms | 0% | AS13004 | SOX - Serbian Open Exchange DOO, RS |
Rate-limited ICMPv6: hop 3 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).
tracepath -6
1?: [LOCALHOST] 0.023ms pmtu 9000
1: fw1-lju.6connect.com 0.739ms
1: fw1-lju.6connect.com 0.557ms
2: no reply
3: 2a00:ee1:800:9::1 2.409ms
4: 2a00:ee0:1:15::2 1.410ms asymm 3
5: 2a00:ee0:1:10::2 70.887ms pmtu 1500
5: de-cix1.rt.act.fkt.de.retn.net 14.057ms asymm 9
6: RT.IRX.VIE.AT.retn.net 14.404ms
7: GW-AS13004.retn.net 49.247ms asymm 8
8: 2001:7f8:1e:3::166 49.006ms !A
Resume: pmtu 1500 From SLO host (T-2) openRFC 4890 ✓
filter likely at: (none) · min PMTU on path: 1500
Path (traceroute + mtr + PTR)
| # | IP / PTR | RTT | mtr loss | AS | AS holder |
|---|---|---|---|---|---|
| 1 | 2a01:261:313:b814::1 | 0.3ms | 0%* | AS34779 | T-2-AS - T-2, d.o.o., SI |
| 2 | 2a01:260:1::225 | 1.5ms | 0%* | AS34779 | T-2-AS - T-2, d.o.o., SI |
| 3 | 2a01-260-1-1--9c.core6.t-2.net 2a01:260:1:1::9c | 2.5ms | 0%* | AS34779 | T-2-AS - T-2, d.o.o., SI |
| 4 | 2a01-260-1-1--38.core6.t-2.net 2a01:260:1:1::38 | 2.1ms | - | AS34779 | T-2-AS - T-2, d.o.o., SI |
| 5 | * | - | 0% | - | |
| 6 | 100ge0-0-0-31.core1.vie1.he.net 2001:470:0:4a8::1 | 10.8ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 7 | e0-35.core2.bts1.he.net 2001:470:0:412::2 | 11.9ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 8 | serbian-open-exchange-doo.10gigabitethernet1-1-2.switch1.beg1.he.net 2001:470:1:6e5::2 | 20.0ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
| 9 | serbian-open-exchange-doo.10gigabitethernet1-1-2.switch1.beg1.he.net 2001:470:1:6e5::2 | 19.6ms | 0% | AS6939 | HURRICANE - Hurricane Electric LLC, US |
tracepath -6
1?: [LOCALHOST] 0.030ms pmtu 1500
1: 2a01:261:313:b814::1 1.567ms
1: 2a01:261:313:b814::1 0.631ms
2: 2a01:260:1::225 13.652ms
3: 2a01-260-1-1--9c.core6.t-2.net 3.281ms
4: 2a01-260-1-1--38.core6.t-2.net 3.005ms asymm 3
5: 100ge0-0-0-31.core1.vie1.he.net 11.677ms
6: 100ge0-0-0-31.core1.vie1.he.net 13.138ms asymm 5
7: e0-36.core2.beg1.he.net 18.842ms
8: serbian-open-exchange-doo.10gigabitethernet1-1-2.switch1.beg1.he.net 20.598ms asymm 7
9: serbian-open-exchange-doo.10gigabitethernet1-1-2.switch1.beg1.he.net 31.833ms asymm 7
10: 2001:7f8:1e:3::166 19.694ms !A
Resume: pmtu 1500