AS209634 - ExplorerServizi Explorer Servizi S.R.LPARFC 4890 ✓RPKI ✓ 1/1ASPA -

AS overview

Test target: 2a09:840::2 · static prefix probe · address space: PA · prefixes announced: 1

prefix(es): 2a09:840::/32

MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO peering

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

We probed 35 arbitrary IPv6 address(es) inside AS209634's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a07:2e80:0:307::2 at hop 20 - that router answers ICMPv6 Echo. This is not in AS209634'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 2026-09-23T12:06:08Z

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)

tracepath -6

 1?: [LOCALHOST]                        0.016ms pmtu 1500
 1:  _gateway                                              7.508ms 
 1:  _gateway                                              0.553ms 
 2:  sox-pn.sox.rs                                        32.559ms 
 3:  2001:7f8:1e:8::3d                                     0.762ms asymm  2 
 4:  2001:67c:128c::699                                   18.167ms 
 5:  2a09:840::2                                          46.050ms reached
     Resume: pmtu 1500 hops 5 back 7 

From DE host (Berlin)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.016ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.520ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.457ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.794ms 
 3:  ae0-150.cr10.fra01.lwlcom.net                        10.120ms asymm  7 
 4:  ae0-100.cr10.fra02.lwlcom.net                        10.558ms asymm  8 
 5:  ae0-10.cr10.fra06.lwlcom.net                         10.107ms asymm  7 
 6:  ams-ix.1-ix.net                                      20.704ms asymm  8 
 7:  2001:7f8:1::a500:1267:1                              34.425ms 
 8:  2a02:b000:fff::1a8                                   36.977ms 
 9:  2a02:b000:fff::ee33                                  30.516ms 
10:  2a02:b000:fff::c7b                                   30.302ms 
11:  no reply
12:  2a02:b011:6ffc:1::5                                  28.902ms 
13:  2a07:2e80:0:2::1                                     34.081ms asymm 11 
14:  2a07:2e80:0:307::2                                   33.038ms asymm 12 
15:  2a09:840::2                                          32.946ms reached
     Resume: pmtu 1500 hops 15 back 13 

From DE host (Düsseldorf)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.018ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.322ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.334ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            1.235ms 
 3:  no reply
 4:  lag30.core3-dus1.bb.wiit.network                      0.365ms 
 5:  lag0-vl1011.core1-fra-ix.bb.wiit.network              4.550ms 
 6:  lag0-vl1001.core1-nbg-ncd.bb.wiit.network             7.222ms 
 7:  lag0-vl6.core2-nbg-ncd.bb.wiit.network                6.955ms 
 8:  lag0-vl1006.core2-muc2.bb.wiit.network                9.792ms 
 9:  lag0-vl1009.core1-muc-eq3.bb.wiit.network             9.984ms 
10:  lag0-vl1001.core1-pda-vsix.bb.wiit.network           20.339ms 
11:  lag0-vl1001.core1-mil-mix.bb.wiit.network            20.257ms asymm  9 
12:  supernap-v6.mix-it.net                               21.095ms asymm 10 
13:  2a07:2e80:0:307::2                                   20.622ms asymm 11 
14:  2a09:840::2                                          20.823ms reached
     Resume: pmtu 1500 hops 14 back 12 

From NL host (go6lab)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

Rate-limited ICMPv6: hop 8 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.034ms pmtu 1500
 1:  2a00:8642:42::2                                       3.829ms 
 1:  2a00:8642:42::2                                       1.510ms 
 2:  no reply
 3:  2a00:1ca8:1::194                                      5.155ms 
 4:  2a03:3f40::10:41                                     19.175ms 
 5:  2001:978:2:40::3:1                                   15.313ms 
 6:  be3458.ccr42.ams03.atlas.cogentco.com                19.385ms 
 7:  2001:978:3::26                                       13.649ms asymm  6 
 8:  adm-bb1-link.ip.twelve99.net                          9.955ms asymm  7 
 9:  no reply
10:  mno-b8-link.ip.twelve99.net                          34.998ms asymm  9 
11:  2a09:840::2                                          30.889ms reached
     Resume: pmtu 1500 hops 11 back 13 

From ITA host (Karsolink)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.030ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        1.112ms 
 1:  karsolink-01.net.karsolink.com                        0.865ms 
 2:  2a12:d8c0:109f:121::a1                                0.848ms 
 3:  2a12:d8c0:101f:103::1                                 9.071ms 
 4:  supernap-v6.mix-it.net                               10.246ms 
 5:  2a07:2e80:0:307::2                                    9.406ms 
 6:  2a09:840::2                                           9.625ms reached
     Resume: pmtu 1500 hops 6 back 6 

From SLO host (6connect)   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]                        0.025ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.642ms 
 1:  fw1-lju.6connect.com                                  0.462ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  0.890ms 
 4:  2a03:a100:0:201:1::1                                  0.860ms pmtu 1500
 4:  e0-1.core1.lju1.he.net                                1.981ms 
 5:  no reply
 6:  port-channel1.core1.zag2.he.net                       4.190ms 
 7:  no reply
 8:  supernap-v6.mix-it.net                               11.454ms asymm  7 
 9:  2a07:2e80:0:307::2                                   10.813ms asymm  7 
10:  2a09:840::2                                          10.747ms reached
     Resume: pmtu 1500 hops 10 back 8 

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]                        0.026ms pmtu 1500
 1:  2a01:261:313:b814::1                                  1.274ms 
 1:  2a01:261:313:b814::1                                  1.005ms 
 2:  2a01:260:1::225                                       3.787ms 
 3:  2a01-260-1-1--9c.core6.t-2.net                        2.808ms 
 4:  hurricane-electric.nikhef.nlsix.net                  33.887ms 
 5:  be1.core2.fra2.he.net                                39.979ms 
 6:  be1.core2.fra2.he.net                                39.169ms asymm  5 
 7:  be3.core4.fra1.he.net                                46.297ms 
 8:  be1.core1.mil2.he.net                                38.353ms asymm  7 
 9:  be1.core1.mil2.he.net                                38.946ms asymm  7 
10:  no reply
11:  2a07:2e80:0:307::2                                   34.862ms asymm  8 
12:  2a09:840::2                                          30.774ms reached
     Resume: pmtu 1500 hops 12 back 7