AS56635 - XenyaPARFC 4890 ✓RPKI ✓ 1/1ASPA ✓

AS overview

Test target: 2a03:a100:0:200::25 · via IPv6 Hitlist (responsive) · address space: PA · prefixes announced: 1

prefix(es): 2a03:a100::/32

SIX peering

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

At least one router inside AS56635's announced prefix replied during the random-target probe. Hop(s): 2a03:a100:0:201:1::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 2026-09-23T10:35:37Z

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

tracepath -6

 1?: [LOCALHOST]                        0.016ms pmtu 1500
 1:  _gateway                                              0.684ms 
 1:  _gateway                                              0.664ms 
 2:  sox-pn.sox.rs                                         2.505ms 
 3:  2001:7f8:1e:8::3d                                     0.875ms asymm  2 
 4:  2001:67c:128c::699                                   18.151ms 
 5:  hu0-15-0-0.lontr4.London.opentransit.net             41.849ms asymm  6 
 6:  no reply
 7:  be4.core2.ams2.he.net                                41.307ms 
 8:  be1.core2.fra2.he.net                                40.724ms asymm  6 
 9:  be4.core1.vie1.he.net                                40.587ms asymm  5 
10:  e0-36.core1.lju1.he.net                              44.503ms asymm  6 
11:  xenya-d-o-o.e0-1.core1.lju1.he.net                   43.689ms asymm  7 
12:  2a03:a100:0:200::25                                  44.486ms reached
     Resume: pmtu 1500 hops 12 back 8 

From DE host (Berlin)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.020ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.833ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.827ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                       26.635ms 
 3:  ae0-40.cr10.muc02.lwlcom.net                         11.997ms 
 4:  ae0-10.cr10.muc01.lwlcom.net                         11.803ms 
 5:  2001:7f8:30:0:2:1:0:3212                             21.286ms asymm  7 
 6:  no reply
 7:  2a00:fc0:4314:b::b                                   26.149ms 
 8:  2a03:a100:0:200::25                                  25.726ms reached
     Resume: pmtu 1500 hops 8 back 8 

From DE host (Düsseldorf)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

Rate-limited ICMPv6: hop 2, hop 3, hop 4, hop 5 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.014ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.620ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.587ms 
 2:  ipv6.decix-dusseldorf.core1.dus1.he.net               7.022ms asymm  3 
 3:  no reply
 4:  be8.core1.prg1.he.net                                13.279ms asymm  5 
 5:  no reply
 6:  e0-36.core1.lju1.he.net                              21.284ms asymm  5 
 7:  six.xenya.si                                         19.887ms asymm  6 
 8:  2a03:a100:0:200::25                                  19.968ms 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)

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]                        0.031ms pmtu 1500
 1:  ???                                                 823.471ms 
 1:  ???                                                   5.955ms 
 2:  no reply
 3:  speed-ix.he.net                                       5.631ms 
 4:  be2.core4.fra1.he.net                                14.590ms 
 5:  be8.core1.prg1.he.net                                17.726ms 
 6:  be3.core1.vie1.he.net                                21.216ms 
 7:  e0-36.core1.lju1.he.net                              25.972ms 
 8:  xenya-d-o-o.e0-1.core1.lju1.he.net                   24.295ms 
 9:  2a03:a100:0:200::25                                  26.034ms reached
     Resume: pmtu 1500 hops 9 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]                        0.028ms pmtu 1500
 1:  no reply
 2:  no reply
 3:  2a12:d8c0:101f:6::1                                   9.850ms 
 4:  no reply
 5:  e0-35.core1.zag2.he.net                              19.327ms 
 6:  no reply
 7:  e0-35.core1.lju1.he.net                              21.715ms 
 8:  xenya-d-o-o.e0-1.core1.lju1.he.net                   20.080ms 
 9:  2a03:a100:0:200::25                                  20.068ms reached
     Resume: pmtu 1500 hops 9 back 9 

From SLO host (6connect)   openRFC 4890 ✓

filter likely at: (none) · min PMTU on path: 9000

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]                        0.027ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.769ms 
 1:  fw1-lju.6connect.com                                  0.626ms 
 2:  ccr-to-fw-ccr1-gw-lju.6connect.com                    5.179ms 
 3:  2a03:a100:0:201:1::1                                  1.266ms 
 4:  2a03:a100:0:200::25                                   1.230ms reached
     Resume: pmtu 9000 hops 4 back 4 

From SLO host (T-2)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.025ms pmtu 1500
 1:  no reply
 2:  2a01:260:1::225                                       5.606ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        3.254ms 
 4:  2a03:a100:0:200::25                                   2.661ms reached
     Resume: pmtu 1500 hops 4 back 4