AS28682 - Pošta SlovenijePI/PARFC 4890 ✓RPKI ✓ 1/1ASPA -

AS overview

Test target: 2a01:9ce0:0:1:7ec2:55ff:fe25:2c00 · via IPv6 Hitlist (responsive) · address space: mixed · prefixes announced: 1

prefix(es): 2a01:9ce0::/32

SIX peering

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

We probed 35 arbitrary IPv6 address(es) inside AS28682's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a00:fc0:4320:c::b at hop 24 - that router does not answer ICMPv6 Echo. This is not in AS28682'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

Vantage points disagree about Type 2 acceptance - transit ASes on one path may be filtering Type 2 even though the destination's stack accepts it on another path:

• SRB host (SOX, Belgrade): inconclusive: no Echo Reply to 1300-byte probe. (ICMPv6 Echo + forged PTB)
• DE host (Berlin): inconclusive: no Echo Reply to 1300-byte probe. (ICMPv6 Echo + forged PTB)
• DE host (Düsseldorf): inconclusive: no Echo Reply to 1300-byte probe. (ICMPv6 Echo + forged PTB)
• NL host (go6lab): inconclusive: no Echo Reply to 1300-byte probe. (ICMPv6 Echo + forged PTB)
• ITA host (Karsolink): Type 2 honored. Forged PTB accepted; next response shrunk. (ICMPv6 Echo + forged PTB)
• SLO host (6connect): Type 2 honored. Forged PTB accepted; next response shrunk. (ICMPv6 Echo + forged PTB)
• SLO host (T-2): Type 2 honored. Forged PTB accepted; next response shrunk. (ICMPv6 Echo + forged PTB)

Why they disagree - reachability mismatch: One vantage couldn't drive a flow at all to this destination (no Echo Reply or no responding TCP port), so the active test had no behavioural change to observe. The other vantage's verdict is the only meaningful one here.

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)   icmp blocked

filter likely at: past AS3212 (TELEMACH) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

Rate-limited ICMPv6: hop 4, hop 5, hop 7 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.040ms pmtu 1500
 1:  _gateway                                              0.575ms 
 1:  _gateway                                              0.795ms 
 2:  sox-pn.sox.rs                                         0.535ms 
 3:  2001:7f8:1e:8::3d                                     0.673ms asymm  2 
 4:  ae8-930.RT.IRX.VIE.AT.retn.net                       12.759ms asymm  3 
 5:  2001:7f8:30:0:2:1:0:3212                             14.261ms asymm  3 
 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
16:  no reply
17:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From DE host (Berlin)   icmp blocked

filter likely at: past AS50629 (LWLCOM) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

Rate-limited ICMPv6: hop 6, hop 7 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.022ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.387ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.365ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.746ms 
 3:  ae0-40.cr10.muc02.lwlcom.net                         11.372ms 
 4:  ae0-10.cr10.muc01.lwlcom.net                         11.506ms 
 5:  2001:7f8:30:0:2:1:0:3212                             21.068ms asymm  7 
 6:  2a00:fc0:4320:c::a                                   25.411ms asymm  8 
 7:  2a00:fc0:4320:c::b                                   24.065ms asymm  9 
 8:  no reply
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From DE host (Düsseldorf)   icmp blocked

filter likely at: past AS3212 (TELEMACH) · 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]                        0.016ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                 12.697ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.217ms 
 2:  ae0-101.cr10.dus02.lwlcom.net                         0.449ms 
 3:  ae0-40.cr10.dus05.lwlcom.net                          0.336ms 
 4:  ae0-10.cr10.ams02.lwlcom.net                          3.505ms 
 5:  2001:7f8:13::a500:3212:1                             22.507ms asymm  7 
 6:  2a00:fc0:4320:c::a                                   24.318ms asymm  7 
 7:  2a00:fc0:4320:c::b                                   22.897ms asymm  8 
 8:  no reply
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From NL host (go6lab)   icmp blocked

filter likely at: past AS3212 (TELEMACH) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

Rate-limited ICMPv6: hop 6, hop 7 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.053ms pmtu 1500
 1:  2a00:8642:42::2                                       3.805ms 
 1:  2a00:8642:42::2                                       4.498ms 
 2:  no reply
 3:  2a00:1ca8:1::194                                      4.621ms 
 4:  2a03:3f40::10:33                                      8.231ms 
 5:  2001:7f8:13::a500:3212:1                             24.080ms asymm  8 
 6:  2a00:fc0:4320:c::a                                   32.338ms asymm  8 
 7:  2a00:fc0:4320:c::b                                   30.881ms asymm  9 
 8:  no reply
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From ITA host (Karsolink)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

Rate-limited ICMPv6: hop 3, hop 7, hop 9, hop 10 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.029ms pmtu 1500
 1:  no reply
 2:  no reply
 3:  2a12:d8c0:101f:103::1                                 8.637ms 
 4:  no reply
 5:  be47.core1.mil2.he.net                               12.976ms 
 6:  be1.core1.zrh2.he.net                                13.852ms 
 7:  be10.core4.fra1.he.net                               21.547ms 
 8:  no reply
 9:  decix.softnet.si                                     18.346ms asymm  6 
10:  sn-lju-hu-0-1-0-0-81-slo.ntwk.softnet.si             26.573ms asymm  8 
11:  2a02:800:1:2001::3                                   27.253ms asymm  9 
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From SLO host (6connect)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.019ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.708ms 
 1:  fw1-lju.6connect.com                                  0.779ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  1.166ms 
 4:  2a03:a100:0:201:1::1                                  1.224ms pmtu 1500
 4:  2001:7f8:46:0:1:0:2:8682                              2.528ms asymm  5 
 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
16:  no reply
17:  no reply
     Too many hops: pmtu 1500

From SLO host (T-2)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.026ms pmtu 1500
 1:  2a01:261:313:b814::1                                  1.059ms 
 2:  2a01:260:1::225                                       8.601ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        2.510ms 
 4:  2001:7f8:46:0:1:0:2:8682                              3.064ms 
 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
16:  no reply
17:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500