AS21283 - A1 SlovenijaPARPKI ✓ 3/3ASPA -

AS overview

Test target: 2001:15c0:1000:1001::2 · via IPv6 Hitlist (responsive) · address space: PA · prefixes announced: 3

prefix(es): 2a00:1a20::/29, 2a00:1a20::/32, 2001:15c0::/29

SIX peering

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

We probed 51 arbitrary IPv6 address(es) inside AS21283's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2001:978:2:40::3:1 at hop 24 - that router answers ICMPv6 Echo. This is not in AS21283'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 active test inconclusive: no Echo Reply to 1300-byte probe.
method: ICMPv6 Echo + forged PTB, tested 2026-09-23T10:31:32Z

sudo tcpdump -i any -n -e 'icmp6 and ip6[40] = 2 and (src host 2607:fae0:a000::42 or src host 2a00:8642:42::75 or src host 2a01:261:313:b814:2a0:98ff:fe5b:13e4 or src host 2a06:d1c1:10b::cccc or src host 2a06:d1c1:10d::aaaa or src host 2a09:ab81::91 or src host 2a12:d8c0:105a:9001::a154)'

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)   all blocked

filter likely at: past AS13004 (SOX) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.020ms pmtu 1500
 1:  _gateway                                              0.362ms 
 1:  _gateway                                              0.300ms 
 2:  sox-pn.sox.rs                                         0.389ms 
 3:  no reply
 4:  no reply
 5:  no reply
 6:  no reply
 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
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From DE host (Berlin)   all blocked

filter likely at: past AS59645 (WYBT-NET) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.049ms pmtu 1500
 1:  no reply
 2:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.505ms !N
     Resume: pmtu 1500 

From DE host (Düsseldorf)   all blocked

filter likely at: past AS59645 (WYBT-NET) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.023ms pmtu 1500
 1:  no reply
 2:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.552ms !N
     Resume: pmtu 1500 

From NL host (go6lab)   all blocked

filter likely at: past AS174 (COGENT-174) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.030ms pmtu 1500
 1:  ???                                                   1.690ms 
 1:  ???                                                   6.779ms 
 2:  no reply
 3:  2a00:1ca8:1::194                                      3.484ms 
 4:  2a03:3f40::10:41                                      3.180ms 
 5:  2001:978:2:40::3:1                                    7.294ms !N
     Resume: pmtu 1500 

From ITA host (Karsolink)   all blocked

filter likely at: past AS204471 (KARSOLINK) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.078ms pmtu 1500
 1:  no reply
 2:  no reply
 3:  2a12:d8c0:109f:121::a1                                0.711ms !N
     Resume: pmtu 1500 

From SLO host (6connect)   all blocked

filter likely at: past AS8038 (6CONNECT) · min PMTU on path: 9000

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.027ms pmtu 9000
 1:  fw1-lju.6connect.com                                  2.783ms 
 1:  fw1-lju.6connect.com                                  0.690ms 
 2:  no reply
 3:  no reply
 4:  no reply
 5:  no reply
 6:  no reply
 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
     Too many hops: pmtu 9000
     Resume: pmtu 9000 

From SLO host (T-2)   all blocked

filter likely at: past AS34779 (T-2-AS) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.025ms pmtu 1500
 1:  2a01:261:313:b814::1                                  0.816ms 
 1:  2a01:261:313:b814::1                                  0.812ms 
 2:  2a01:260:1::225                                      14.448ms 
 3:  no reply
 4:  no reply
 5:  no reply
 6:  no reply
 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
     Too many hops: pmtu 1500
     Resume: pmtu 1500