AS39479 - NS3-ASN NS3 s.r.lRFC 4890 ✓RPKI ⚠ 1/2ASPA -

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AS overview

Test target: 2a07:2841::11 · ns2.rhx.info · address space: unknown · prefixes announced: 2

prefix(es): 2a07:2841::/32, 2a05:eb80::/29

Targets & per-vantage-point probe results (3 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 / hostnameSourceSRB host (SOX, Belgrade)DE host (Berlin)DE host (Düsseldorf)NL host (go6lab)ITA host (Karsolink)SLO host (6connect)SLO host (T-2)
ping1500B:80:443reachedping1500B:80:443reachedping1500B:80:443reachedping1500B:80:443reachedping1500B:80:443reachedping1500B:80:443reachedping1500B:80:443reached
2a07:2841::11
ns2.rhx.info
NS?open-?open-?open-?open-?open-?open-?open-
2a07:2841::3:41
www.rhx.it
whoisopenopen-openopen-openopen-openopen-openopen-openopen-openopen-
2a07:2841::9
monitor.rhx.it
whoisopenopen-openopen-openopen-openopen-openopen-openopen-openopen-

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 2022-04-14. IPv6 LAN: 2001:7f8:b:100:1d1:a5d3:9479:169. Locations: -.

RPKI & ASPA

1 of 2 prefix(es) covered by a valid ROA, 1 not-found.

PrefixRPKI stateReasonCovering VRP(s)
2a07:2841::/32- not-foundno covering VRP
2a05:eb80::/29✓ validmatched VRP (correct origin, length within maxLength)AS39479 /29 maxLen 29 (ripe)

Random-IP probe (yarrp) into the AS' prefixes

At least one router inside AS39479's announced prefix replied during the random-target probe. Hop(s): 2a05:eb80:0:1::840:1, 2a05:eb87:1:103::3, 2a05:eb87:1:105::3, 2a05:eb87:1:109::4, 2a05:eb87:1:110::1. These are candidate targets for direct testing.

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 2026-09-23T12:05:28Z

Where the path divergence is

Per-vantage probe + verdict (headline):

Full per-method matrix (all four methods run at each vantage):

vantageicmp6-echodns-tcptlshttp
belgradehonoredinconclusivepartialno_tcp
berlinhonoredinconclusivenot_honoredno_tcp
duseldorfhonoredinconclusivepartialno_tcp
go6labhonoredinconclusivenot_honoredno_tcp
karsolinkhonoredinconclusivenot_honoredno_tcp
odinhonoredinconclusivenot_honoredno_tcp
t2honoredinconclusivenot_honoredno_tcp

✓ 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): AS39479, AS50877, AS6939.

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

An operator-targeted diagnostic interpretation can be generated for this AS on demand. The pipeline holds the raw verdicts and the per-hop walk; an AI pass synthesises where to start looking. Click the button below to run it.

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 ↗

multi-vantage path diagram for AS39479

From SRB host (SOX, Belgrade)   openRFC 4890 ✓

filter likely at: (none) · min PMTU on path: 1500

4/4
Echo small (56B) 23.9ms
4/4
Echo 1500B (DF) 23.8ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
12a09:ab81::10.4ms0%*AS60733PERKE-NET - ZORAN PEROVIC trading as Agencija Perke.NET, RS
2sox-pn.sox.rs
2001:7f8:1e:8::3a
0.2ms0%AS13004SOX - Serbian Open Exchange DOO, RS
3*-10%-
4*-10%-
5100ge0-0-0-2.core1.vie1.he.net
2001:470:0:412::1
11.5ms20%AS6939HURRICANE - Hurricane Electric LLC, US
6*---
7ns3-AS39479-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:a5d3:9479:169
22.8ms0%-NA
82a05:eb87:1:109::423.5ms0%AS39479NS3-ASN - NS3 s.r.l., IT
92a05:eb80:0:1::840:123.4ms0%AS39479NS3-ASN - NS3 s.r.l., IT
10*-0%-
11*---
12*---
13*---
14*---
15*---
16*---
17*---
18*---
19*---

Rate-limited ICMPv6: hop 3, hop 4, hop 5 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.022ms pmtu 1500
 1:  _gateway                                              0.423ms 
 1:  _gateway                                              0.737ms 
 2:  sox-pn.sox.rs                                         0.384ms 
 3:  e0-33.core2.beg1.he.net                               3.803ms 
 4:  e0-34.core2.bts1.he.net                               8.950ms 
 5:  no reply
 6:  no reply
 7:  ns3-AS39479-v6.mix-it.net                            23.090ms 
 8:  2a05:eb87:1:105::3                                   29.997ms 
 9:  2a05:eb80:0:1::840:1                                 23.677ms 
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
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From DE host (Berlin)   openRFC 4890 ✓

filter likely at: (none) · min PMTU on path: 1500

4/4
Echo small (56B) 46.8ms
4/4
Echo 1500B (DF) 47.0ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1*-0%*-
2ae0-2453.cr10.ber01.lwlcom.net
2a06:d1c0::dead:beef:1c02
0.6ms0%*AS59645WYBT-NET - Tobias Fiebig, DE
3ae0-150.cr10.fra01.lwlcom.net
2a00:c380:b200:230::174
10.0ms0%AS50629LWLCOM - LWLcom GmbH, DE
4ae0-100.cr10.fra02.lwlcom.net
2a00:c380:b200:230::215
10.3ms0%AS50629LWLCOM - LWLcom GmbH, DE
5ae0-10.cr10.fra06.lwlcom.net
2a00:c380:b200:230::236
9.9ms0%AS50629LWLCOM - LWLcom GmbH, DE
6tbiss.1-ix.net
2001:7f8:115:1::1:22
32.3ms0%-NA
7*---
82a0a:f980:0:104::245.3ms0%AS50877AIRBEAM-AS - Airbeam S.r.l., IT
92a0a:f980:1:101::245.1ms0%AS50877AIRBEAM-AS - Airbeam S.r.l., IT
102a05:eb87:1:103::345.7ms0%AS39479NS3-ASN - NS3 s.r.l., IT
112a05:eb80:0:1::840:145.7ms0%AS39479NS3-ASN - NS3 s.r.l., IT
12*-0%-
13*---
14*---
15*---
16*---
17*---
18*---
19*---

tracepath -6

 1?: [LOCALHOST]                        0.015ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.343ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.322ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.698ms 
 3:  ae0-150.cr10.fra01.lwlcom.net                        10.236ms asymm  7 
 4:  ae0-100.cr10.fra02.lwlcom.net                        10.453ms asymm  8 
 5:  ae0-10.cr10.fra06.lwlcom.net                         10.053ms asymm  7 
 6:  tbiss.1-ix.net                                       32.449ms asymm  7 
 7:  no reply
 8:  2a0a:f980:0:104::2                                   45.606ms asymm 12 
 9:  2a0a:f980:1:101::2                                   45.528ms asymm 13 
10:  2a05:eb87:1:103::3                                   46.546ms 
11:  2a05:eb80:0:1::840:1                                 46.049ms 
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From DE host (Düsseldorf)   openRFC 4890 ✓

filter likely at: (none) · min PMTU on path: 1500

4/4
Echo small (56B) 24.5ms
4/4
Echo 1500B (DF) 24.6ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1*-0%*-
2eth1-0-12-h5594.edge5-dus1.bb.wiit.network
2001:4ba0:92f4:3::1
30.0ms0%AS24961MYLOC-AS - WIIT AG, DE
3lag10-h5f01.agr4-dus1.bb.wiit.network
2001:4ba0:ffe9:7c::1
471.1ms0%AS24961MYLOC-AS - WIIT AG, DE
4lag11.core3-dus1.bb.wiit.network
2001:4ba0:ffe9:115::3
0.2ms0%AS24961MYLOC-AS - WIIT AG, DE
5lag0-vl1011.core1-fra-ix.bb.wiit.network
2001:4ba0:ffe9:8a::2
4.2ms0%AS24961MYLOC-AS - WIIT AG, DE
6lag0-vl1001.core1-nbg-ncd.bb.wiit.network
2001:4ba0:ffe9:103e::1
6.7ms0%AS24961MYLOC-AS - WIIT AG, DE
7lag0-vl6.core2-nbg-ncd.bb.wiit.network
2001:4ba0:ffe9:103b::1
6.8ms0%AS24961MYLOC-AS - WIIT AG, DE
82001:4ba0:ffe9:b89.7ms0%-
9lag0-vl1009.core1-muc-eq3.bb.wiit.network
2001:4ba0:ffe9:a7::1
9.9ms0%AS24961MYLOC-AS - WIIT AG, DE
10lag0-vl1001.core1-pda-vsix.bb.wiit.network
2001:4ba0:ffe9:da::2
20.3ms0%AS24961MYLOC-AS - WIIT AG, DE
11lag0-vl1001.core1-mil-mix.bb.wiit.network
2001:4ba0:ffe9:db::2
19.9ms0%AS24961MYLOC-AS - WIIT AG, DE
12ns3-AS39479-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:a5d3:9479:169
24.2ms0%-NA
132a05:eb87:1:105::324.0ms0%AS39479NS3-ASN - NS3 s.r.l., IT
142a05:eb80:0:1::840:124.1ms0%AS39479NS3-ASN - NS3 s.r.l., IT
15*-0%-
16*---
17*---
18*---
19*---

tracepath -6

 1?: [LOCALHOST]                        0.036ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.702ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.316ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network           18.262ms 
 3:  no reply
 4:  lag11.core3-dus1.bb.wiit.network                      0.641ms 
 5:  lag0-vl1011.core1-fra-ix.bb.wiit.network              4.286ms 
 6:  lag0-vl1001.core1-nbg-ncd.bb.wiit.network             7.070ms 
 7:  lag0-vl6.core2-nbg-ncd.bb.wiit.network                6.739ms 
 8:  lag0-vl1006.core2-muc2.bb.wiit.network                9.605ms 
 9:  lag0-vl1009.core1-muc-eq3.bb.wiit.network             9.686ms 
10:  lag0-vl1001.core1-pda-vsix.bb.wiit.network           20.368ms 
11:  lag0-vl1001.core1-mil-mix.bb.wiit.network            20.417ms asymm  9 
12:  ns3-AS39479-v6.mix-it.net                            88.747ms asymm  8 
13:  2a05:eb87:1:105::3                                   23.971ms asymm  9 
14:  2a05:eb80:0:1::840:1                                 24.174ms asymm 10 
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From NL host (go6lab)   openRFC 4890 ✓

filter likely at: (none) · min PMTU on path: 1500

4/4
Echo small (56B) 30.4ms
4/4
Echo 1500B (DF) 28.9ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
12a00:8642:42::20.3ms0%AS203993GNA-DC1-AS - S.J.M. Steffann, NL
2gw.friends.steffann.nl
2a00:8642:1000:f000::1
1.8ms0%*AS203993GNA-DC1-AS - S.J.M. Steffann, NL
32a00:1ca8:1::1941.7ms0%AS50673Serverius-as - Serverius Holding B.V., NL
42a03:3f40::10:334.5ms0%AS50673Serverius-as - Serverius Holding B.V., NL
5ams-ix.retn.net
2001:7f8:1::a500:9002:1
4.7ms0%-NA
6RT.VSX.PDA.IT.retn.net
2a02:2d8::57f5:e07e
22.5ms0%AS9002RETN-AS - RETN Limited, GB
7GW-NetGlobal.retn.net
2a02:2d8:4:180d:232a::1
31.7ms0%AS9002RETN-AS - RETN Limited, GB
8*---
92a05:eb87:1:110::125.0ms10%AS39479NS3-ASN - NS3 s.r.l., IT
102a05:eb80:0:1::840:125.3ms0%AS39479NS3-ASN - NS3 s.r.l., IT
11*-0%-
12*---
13*---
14*---
15*---
16*---
17*---
18*---
19*---

Rate-limited ICMPv6: hop 9 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.029ms pmtu 1500
 1:  2a00:8642:42::2                                       3.419ms 
 1:  2a00:8642:42::2                                       5.352ms 
 2:  gw.friends.steffann.nl                                7.629ms 
 3:  2a00:1ca8:1::194                                      5.740ms 
 4:  2a03:3f40::10:33                                      6.765ms 
 5:  ams-ix.retn.net                                       7.812ms asymm  7 
 6:  RT.VSX.PDA.IT.retn.net                               23.017ms 
 7:  GW-NetGlobal.retn.net                                23.568ms asymm  8 
 8:  no reply
 9:  2a05:eb87:1:110::1                                   28.456ms asymm 13 
10:  2a05:eb80:0:1::840:1                                 25.482ms asymm 14 
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
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From ITA host (Karsolink)   openRFC 4890 ✓

filter likely at: (none) · min PMTU on path: 1500

4/4
Echo small (56B) 14.9ms
3/4
Echo 1500B (DF) 14.0ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1*-0%*-
2*---
3*---
42001:7f8:b9::44:112.5ms0%-NA
52a05:eb87:1:109::412.7ms0%AS39479NS3-ASN - NS3 s.r.l., IT
62a05:eb80:0:1::840:112.8ms0%AS39479NS3-ASN - NS3 s.r.l., IT
7*-0%-
8*---
9*---
10*---
11*---
12*---
13*---
14*---
15*---
16*---
17*---
18*---
19*---

tracepath -6

 1?: [LOCALHOST]                        0.028ms pmtu 1500
 1:  no reply
 2:  2a12:d8c0:109f:121::a1                                0.595ms 
 3:  no reply
 4:  2001:7f8:b9::44:1                                    12.761ms 
 5:  2a05:eb87:1:109::4                                   12.605ms 
 6:  2a05:eb80:0:1::840:1                                 13.218ms 
 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
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From SLO host (6connect)   openRFC 4890 ✓

filter likely at: (none) · min PMTU on path: 1500

4/4
Echo small (56B) 15.6ms
3/4
Echo 1500B (DF) 16.0ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1fw1-lju.6connect.com
2607:fae0:a000::2
0.2ms0%*AS80386CONNECT - 6connect, Inc., US
2*---
32a03:a100:0:201:1::10.5ms60%AS56635XENYA - XENYA inzeniring, proizvodnja in trgovina, d.o.o. Ljubljana, SI
4e0-1.core1.lju1.he.net
2001:470:1:5be::1
2.1ms-AS6939HURRICANE - Hurricane Electric LLC, US
5*---
6*-70%-
7*---
82001:7f8:5f:ffff::5716.4ms0%-NA
92a05:eb87:1:109::416.4ms0%AS39479NS3-ASN - NS3 s.r.l., IT
102a05:eb80:0:1::840:116.2ms0%AS39479NS3-ASN - NS3 s.r.l., IT
11*-0%-
12*---
13*---
14*---
15*---
16*---
17*---
18*---
19*---

Rate-limited ICMPv6: hop 3, hop 6 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.022ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.494ms 
 1:  fw1-lju.6connect.com                                  0.522ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  2.745ms 
 4:  2a03:a100:0:201:1::1                                  3.447ms pmtu 1500
 4:  no reply
 5:  no reply
 6:  port-channel1.core1.zag2.he.net                       4.188ms 
 7:  no reply
 8:  2001:7f8:5f:ffff::57                                 17.643ms 
 9:  2a05:eb87:1:109::4                                   16.415ms 
10:  2a05:eb80:0:1::840:1                                 16.427ms 
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
     Too many hops: pmtu 1500

From SLO host (T-2)   openRFC 4890 ✓

filter likely at: (none) · min PMTU on path: 1500

4/4
Echo small (56B) 35.5ms
4/4
Echo 1500B (DF) 36.2ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1*---
22a01:260:1::2255.4ms0%*AS34779T-2-AS - T-2, d.o.o., SI
32a01-260-1-1--9a.core6.t-2.net
2a01:260:1:1::9a
6.9ms0%*AS34779T-2-AS - T-2, d.o.o., SI
4hurricane-electric.nikhef.nlsix.net
2001:7f8:13::a500:6939:1
38.5ms0%*-NA
5hurricane-electric.nikhef.nlsix.net
2001:7f8:13::a500:6939:1
40.8ms0%-NA
6*-0%-
7be10.core1.zrh2.he.net
2001:470:e:153::2
48.4ms30%AS6939HURRICANE - Hurricane Electric LLC, US
8be1.core1.mil2.he.net
2001:470:e:dd::1
39.5ms0%AS6939HURRICANE - Hurricane Electric LLC, US
9be1.core1.mil2.he.net
2001:470:e:dd::1
48.0ms0%AS6939HURRICANE - Hurricane Electric LLC, US
10*---
11*-0%-
12*-0%-
132a05:eb80:0:1::840:136.5ms0%AS39479NS3-ASN - NS3 s.r.l., IT
14*-0%-
15*---
16*---
17*---
18*---
19*---

Rate-limited ICMPv6: hop 7 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.026ms pmtu 1500
 1:  no reply
 2:  2a01:260:1::225                                       3.504ms 
 3:  2a01-260-1-1--9c.core6.t-2.net                        2.341ms 
 4:  hurricane-electric.nikhef.nlsix.net                  33.966ms 
 5:  be7.core2.fra2.he.net                                37.759ms 
 6:  be3.core4.fra1.he.net                                38.800ms asymm  7 
 7:  be10.core1.zrh2.he.net                               45.086ms asymm  8 
 8:  be1.core1.mil2.he.net                                35.158ms asymm  7 
 9:  be1.core1.mil2.he.net                                35.057ms asymm  7 
10:  ns3-AS39479-v6.mix-it.net                            34.722ms asymm  7 
11:  2a05:eb87:1:109::4                                   36.670ms asymm  8 
12:  2a05:eb80:0:1::840:1                                 35.404ms asymm  9 
13:  2a05:eb80:0:1::840:1                                 37.342ms asymm  9 
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500