AS203466 - INTROSERVPARFC 4890 ✓RPKI ✓ 2/2ASPA -

AS overview

Test target: 2a06:f940:1::1 · static prefix probe · address space: PA · prefixes announced: 2

prefix(es): 2a06:f940:1::/48, 2a06:f940:2::/48

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

We probed 70 arbitrary IPv6 address(es) inside AS203466's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2001:978:2:2c::81 at hop 19 - that router answers ICMPv6 Echo. This is not in AS203466's announced prefix; operationally it's the AS-edge / peering interface (often on a SIX 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 2026-09-23T10:36:02Z

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)

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

tracepath -6

 1?: [LOCALHOST]                        0.014ms pmtu 1500
 1:  _gateway                                              0.526ms 
 1:  _gateway                                              0.583ms 
 2:  sox-pn.sox.rs                                         0.576ms 
 3:  2001:7f8:1e:8::3d                                     0.655ms asymm  2 
 4:  ae8-930.RT.IRX.VIE.AT.retn.net                       13.235ms asymm  3 
 5:  RT.EQX.FKT.DE.retn.net                               23.609ms asymm  4 
 6:  decix.bb01.net.23m.com                               22.092ms asymm  8 
 7:  ae2-0.gw01.fra01.net.23m.com                         21.965ms asymm  9 
 8:  v6.gw.de.introserv.net                               22.057ms reached
     Resume: pmtu 1500 hops 8 back 10 

From DE host (Berlin)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.056ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.613ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.514ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        1.202ms 
 3:  ae0-150.cr10.fra01.lwlcom.net                        10.645ms asymm  7 
 4:  ae0-100.cr10.fra02.lwlcom.net                        10.850ms asymm  8 
 5:  ae0-10.cr10.fra06.lwlcom.net                         10.326ms asymm  7 
 6:  ams-ix.1-ix.net                                      21.391ms asymm  8 
 7:  ams-ix.23m.com                                       16.547ms asymm  5 
 8:  ae4-0.bb02.fra01.net.23m.com                         16.862ms asymm  6 
 9:  ae1-0.gw01.fra01.net.23m.com                         16.814ms asymm  7 
10:  v6.gw.de.introserv.net                               16.474ms reached
     Resume: pmtu 1500 hops 10 back 8 

From DE host (Düsseldorf)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.040ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.459ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.360ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            1.075ms 
 3:  no reply
 4:  lag30.core3-dus1.bb.wiit.network                      0.439ms 
 5:  lag2.core1-dus-ix.bb.wiit.network                     0.584ms 
 6:  decix.bb01.net.23m.com                               13.954ms asymm  5 
 7:  ae2-0.gw01.fra01.net.23m.com                          4.617ms asymm  6 
 8:  v6.gw.de.introserv.net                                4.444ms reached
     Resume: pmtu 1500 hops 8 back 7 

From NL host (go6lab)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.031ms pmtu 1500
 1:  2a00:8642:42::2                                       1.586ms 
 1:  2a00:8642:42::2                                       2.033ms 
 2:  gw.friends.steffann.nl                                4.501ms 
 3:  2a00:1ca8:1::194                                      3.164ms 
 4:  2a03:3f40::10:41                                      3.369ms 
 5:  2001:978:2:40::3:1                                    5.448ms 
 6:  be3457.ccr41.ams03.atlas.cogentco.com                 8.507ms 
 7:  be2950.ccr42.fra05.atlas.cogentco.com                12.888ms 
 8:  be5484.rcr22.fra06.atlas.cogentco.com                12.695ms 
 9:  be4167.nr21.b015759-0.fra06.atlas.cogentco.com       15.960ms 
10:  2001:978:2:42::1d                                    12.112ms asymm  7 
11:  ae2-0.gw01.fra01.net.23m.com                         13.641ms asymm  8 
12:  v6.gw.de.introserv.net                               11.547ms reached
     Resume: pmtu 1500 hops 12 back 9 

From ITA host (Karsolink)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

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

tracepath -6

 1?: [LOCALHOST]                        0.034ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.758ms 
 2:  no reply
 3:  2a12:d8c0:101f:103::1                                 9.027ms 
 4:  2a03:b020:1:51::a                                    10.437ms 
 5:  rt.eqx.fkt.de.retn.net                               16.454ms asymm  6 
 6:  decix.bb01.net.23m.com                               16.733ms 
 7:  ae1-0.gw01.fra01.net.23m.com                         15.928ms 
 8:  v6.gw.de.introserv.net                               16.566ms reached
     Resume: pmtu 1500 hops 8 back 8 

From SLO host (6connect)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

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

tracepath -6

 1?: [LOCALHOST]                        0.019ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.640ms 
 1:  fw1-lju.6connect.com                                  0.713ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  1.251ms 
 4:  2a03:a100:0:201:1::1                                  1.247ms pmtu 1500
 4:  e0-1.core1.lju1.he.net                                2.462ms 
 5:  100ge0-0-0-5.core1.vie1.he.net                        8.332ms 
 6:  be4.core2.fra2.he.net                                18.829ms 
 7:  2001:7f8:15e::80                                     16.944ms 
 8:  ae4-0.bb02.fra01.net.23m.com                         34.039ms 
 9:  ae2-0.gw01.fra01.net.23m.com                         16.841ms 
10:  v6.gw.de.introserv.net                               16.881ms reached
     Resume: pmtu 1500 hops 10 back 10 

From SLO host (T-2)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

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

tracepath -6

 1?: [LOCALHOST]                        0.028ms pmtu 1500
 1:  no reply
 2:  2a01:260:1::225                                       2.583ms 
 3:  2a01-260-1-1--9c.core6.t-2.net                        2.749ms 
 4:  hurricane-electric.nikhef.nlsix.net                  36.055ms 
 5:  hurricane-electric.nikhef.nlsix.net                  40.051ms asymm  4 
 6:  2001:7f8:15e::80                                     41.236ms 
 7:  2001:7f8:15e::80                                     46.793ms asymm  6 
 8:  ae4-0.bb02.fra01.net.23m.com                         40.252ms asymm  7 
 9:  ???                                                  36.272ms reached
     Resume: pmtu 1500 hops 9 back 9