AS8224 - INTERCOM-AS Intercom s.r.lPARFC 4890 ✓RPKI ✓ 1/1ASPA -

AS overview

Test target: 2a01:2d8::ad1 · adns1.intercom.it · address space: PA · prefixes announced: 1

prefix(es): 2a01:2d8::/29

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

At least one router inside AS8224's announced prefix replied during the random-target probe. Hop(s): 2a01:2d8::1:100, 2a01:2d8::1:101, 2a01:2d8::1:103, 2a01:2d8::1:104, 2a01:2d8::1:8. 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 2026-09-23T12:01:29Z

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]                        0.021ms pmtu 1500
 1:  _gateway                                              0.804ms 
 1:  _gateway                                              0.842ms 
 2:  sox-pn.sox.rs                                         0.762ms 
 3:  2001:7f8:1e:8::3d                                     0.698ms asymm  2 
 4:  2001:67c:128c::699                                   19.708ms 
 5:  2a01:2d8::1:a1                                       37.180ms !A
     Resume: pmtu 1500 

From DE host (Berlin)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.038ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.923ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.752ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        1.404ms 
 3:  ae0-150.cr10.fra01.lwlcom.net                        10.691ms asymm  7 
 4:  ae0-100.cr10.fra02.lwlcom.net                        12.556ms asymm  8 
 5:  2001:978:2:42::154:c                                 11.436ms asymm  9 
 6:  be7948.ccr42.fra05.atlas.cogentco.com                10.887ms asymm 10 
 7:  be7944.ccr22.muc03.atlas.cogentco.com                16.883ms asymm 11 
 8:  port-channel5891.ccr91.mil02.atlas.cogentco.com      24.618ms asymm 12 
 9:  be4466.rcr51.b019138-1.mil02.atlas.cogentco.com      25.600ms asymm 13 
10:  2001:978:2:2a::1:2                                   22.252ms asymm 11 
11:  mix-cr1.intercom.it                                  21.795ms asymm 12 
12:  mlc-bkb-1.intercom.it                                22.011ms asymm 11 
13:  2a01:2d8::1:a1                                       21.761ms asymm 12 
14:  2a01:2d8::1:a1                                       21.898ms !A
     Resume: pmtu 1500 

From DE host (Düsseldorf)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.028ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.460ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.513ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network           14.512ms 
 3:  no reply
 4:  lag11.core3-dus1.bb.wiit.network                      0.387ms 
 5:  lag0-vl1011.core1-fra-ix.bb.wiit.network              4.427ms 
 6:  lag0-vl1001.core1-nbg-ncd.bb.wiit.network             6.771ms 
 7:  lag0-vl6.core2-nbg-ncd.bb.wiit.network                6.776ms 
 8:  lag0-vl1006.core2-muc2.bb.wiit.network                9.818ms 
 9:  lag0-vl1009.core1-muc-eq3.bb.wiit.network             9.929ms 
10:  lag0-vl1001.core1-pda-vsix.bb.wiit.network           20.313ms 
11:  lag0-vl1001.core1-mil-mix.bb.wiit.network            20.146ms asymm  9 
12:  lag0-vl5.core3-mil-irid.bb.wiit.network              20.261ms asymm  8 
13:  intercom.minap.it                                    20.372ms asymm  9 
14:  mlc-bkb-1.intercom.it                                20.264ms asymm 10 
15:  2a01:2d8::1:a1                                       20.183ms asymm 11 
16:  2a01:2d8::1:a1                                       20.152ms !A
     Resume: pmtu 1500 

From NL host (go6lab)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.047ms pmtu 1500
 1:  2a00:8642:42::2                                       3.875ms 
 1:  2a00:8642:42::2                                       2.967ms 
 2:  gw.friends.steffann.nl                                5.427ms 
 3:  2a00:1ca8:1::194                                      8.002ms 
 4:  2a03:3f40::10:41                                      5.166ms 
 5:  2001:978:2:40::3:1                                    7.346ms 
 6:  be3458.ccr42.ams03.atlas.cogentco.com                 7.031ms 
 7:  be2950.ccr42.fra05.atlas.cogentco.com                14.851ms 
 8:  be5516.ccr21.muc03.atlas.cogentco.com                19.371ms 
 9:  port-channel5892.ccr92.mil02.atlas.cogentco.com      26.402ms 
10:  be4466.rcr51.b019138-1.mil02.atlas.cogentco.com      30.414ms 
11:  2001:978:2:2a::1:2                                   29.751ms 
12:  2a01:2d8::1:8                                        27.417ms asymm 14 
13:  2a01:2d8::1:100                                      26.349ms 
14:  2a01:2d8::1:a1                                       27.833ms 
15:  2a01:2d8::1:a1                                       26.692ms !A
     Resume: pmtu 1500 

From ITA host (Karsolink)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.036ms pmtu 1500
 1:  no reply
 2:  no reply
 3:  no reply
 4:  intercom-v6.mix-it.net                                9.319ms asymm  5 
 5:  mix-cr1.intercom.it                                   9.473ms asymm  6 
 6:  mlc-bkb-1.intercom.it                                 9.490ms asymm  5 
 7:  2a01:2d8::1:a1                                        9.587ms asymm  6 
 8:  2a01:2d8::1:a1                                        9.599ms !A
     Resume: pmtu 1500 

From SLO host (6connect)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

Rate-limited ICMPv6: hop 4, hop 6 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.018ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.614ms 
 1:  fw1-lju.6connect.com                                  0.569ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  1.249ms 
 4:  2a03:a100:0:201:1::1                                  0.800ms pmtu 1500
 4:  e0-1.core1.lju1.he.net                                2.232ms 
 5:  no reply
 6:  port-channel1.core1.zag2.he.net                       4.215ms 
 7:  no reply
 8:  intercom-v6.mix-it.net                               12.478ms asymm  9 
 9:  mix-cr1.intercom.it                                  12.500ms asymm 10 
10:  mlc-bkb-1.intercom.it                                12.610ms asymm  9 
11:  2a01:2d8::1:a1                                       12.483ms !A
     Resume: pmtu 1500 

From SLO host (T-2)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

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

tracepath -6

 1?: [LOCALHOST]                        0.027ms pmtu 1500
 1:  2a01:261:313:b814::1                                  1.357ms 
 2:  2a01:260:1::225                                      20.349ms 
 3:  2a01-260-1-1--9c.core6.t-2.net                        2.376ms 
 4:  hurricane-electric.nikhef.nlsix.net                  34.830ms 
 5:  hurricane-electric.nikhef.nlsix.net                  34.888ms asymm  4 
 6:  be3.core4.fra1.he.net                                38.710ms asymm  7 
 7:  be10.core1.zrh2.he.net                               44.654ms asymm  8 
 8:  be1.core1.mil2.he.net                                35.640ms asymm  7 
 9:  no reply
10:  intercom.minap.it                                    34.436ms asymm  7 
11:  intercom.minap.it                                    32.034ms asymm  7 
12:  2a01:2d8::1:8                                        31.128ms asymm  9 
13:  2a01:2d8::1:a1                                       32.518ms asymm  9 
14:  2a01:2d8::1:a1                                       32.750ms asymm  9 
15:  2a01:2d8::1:a1                                       31.395ms !A
     Resume: pmtu 1500