AS198524 - iLOLPIRFC 4890 ✓RPKI ✓ 1/1ASPA ✓

AS overview

Test target: 2001:67c:2730:2::3 · ns2.ilol.si · address space: PI · prefixes announced: 1

prefix(es): 2001:67c:2730::/48

SIX peering

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

At least one router inside AS198524's announced prefix replied during the random-target probe. Hop(s): 2001:67c:2730:f9::1, 2001:67c:2730:f9::2. These are candidate targets for direct testing.

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): Type 2 partial. Some shrinkage but not down to 1280 bytes. (TLS handshake + forged PTB)
• DE host (Berlin): Type 2 partial. Some shrinkage but not down to 1280 bytes. (TLS handshake + forged PTB)
• DE host (Düsseldorf): Type 2 partial. Some shrinkage but not down to 1280 bytes. (TLS handshake + forged PTB)
• NL host (go6lab): inconclusive: no Echo Reply after PTB (probe 1500B). (ICMPv6 Echo + forged PTB)
• ITA host (Karsolink): Type 2 partial. Some shrinkage but not down to 1280 bytes. (TLS handshake + forged PTB)
• SLO host (6connect): Type 2 partial. Some shrinkage but not down to 1280 bytes. (TLS handshake + forged PTB)
• SLO host (T-2): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (TLS handshake + forged PTB)

Why they disagree - different probe methods: These vantages picked different probe methods, so their verdicts are not directly comparable. The active test tries methods in order (icmp6-echo → dns-tcp → tls → http) and stops at the first that produces a definitive verdict; if the chosen method differs, the underlying evidence differs too. Most often this is because the path PMTU on one vantage is below 1500 B, so the natural Echo Reply is already fragmented and the icmp6-echo method falls through to a TCP-based one. This is largely a measurement artifact, not a destination-behaviour difference.

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)'

sudo ip6tables -L INPUT -nv | grep -iE 'icmpv6|packet-too-big'
sudo nft list ruleset 2>/dev/null | grep -A1 'icmpv6'

sudo sysctl net.ipv6.conf.all.accept_redirects net.ipv4.ip_no_pmtu_disc net.ipv6.route.mtu_expires

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 2a12:d8c0:105a:9001::a154 or src host 2a09:ab81::91 or src host 2a01:261:313:b814:2a0:98ff:fe5b:13e4 or src host 2a06:d1c1:10a::bbbb or src host 2a06:d1c1:10d::aaaa or src host 2a06:d1c1:10b::cccc)'

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]                        0.010ms pmtu 1500
 1:  _gateway                                              0.609ms 
 1:  _gateway                                              1.095ms 
 2:  sox-pn.sox.rs                                         0.390ms 
 3:  2001:7f8:1e:8::3d                                     0.534ms asymm  2 
 4:  ae8-930.RT.IRX.VIE.AT.retn.net                       12.838ms asymm  3 
 5:  vix6.ilol.si                                         16.404ms asymm  7 
 6:  2001:67c:2730:fa::2                                  16.339ms asymm  8 
 7:  2001:67c:2730:ff::ff                                 16.450ms 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
     Too many hops: pmtu 1500
     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]                        0.020ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.354ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.409ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.909ms 
 3:  ae0-40.cr10.muc02.lwlcom.net                         11.713ms 
 4:  ae0-10.cr10.muc01.lwlcom.net                         11.549ms 
 5:  vix6.ilol.si                                         26.067ms asymm  7 
 6:  2001:67c:2730:fa::2                                  26.010ms asymm  8 
 7:  2001:67c:2730:ff::ff                                 26.266ms 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
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From DE host (Düsseldorf)   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]                        0.018ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                 29.315ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                 10.136ms 
 2:  ae0-101.cr10.dus02.lwlcom.net                         0.600ms 
 3:  ae0-40.cr10.dus05.lwlcom.net                          0.908ms 
 4:  ae0-20.cr10.vel01.lwlcom.net                          1.178ms 
 5:  ae0-30.cr10.dus06.lwlcom.net                         19.332ms 
 6:  ae0-40.cr10.fra06.lwlcom.net                          4.209ms 
 7:  ae0-20.cr10.muc01.lwlcom.net                         15.056ms asymm  5 
 8:  vix6.ilol.si                                         21.189ms asymm  6 
 9:  2001:67c:2730:fa::2                                  21.015ms asymm  7 
10:  2001:67c:2730:ff::ff                                 21.603ms asymm  8 
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

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

tracepath -6

 1?: [LOCALHOST]                        0.037ms pmtu 1500
 1:  2a00:8642:42::2                                       3.183ms 
 1:  2a00:8642:42::2                                       2.159ms 
 2:  gw.friends.steffann.nl                                5.363ms 
 3:  speed-ix.he.net                                       6.349ms 
 4:  be2.core4.fra1.he.net                                11.700ms 
 5:  be8.core1.prg1.he.net                                16.746ms 
 6:  no reply
 7:  e0-36.core1.lju1.he.net                              30.159ms 
 8:  2001:7f8:46::19:8524                                 27.914ms 
 9:  2001:67c:2730:fa::2                                  25.043ms 
10:  2001:67c:2730:ff::ff                                 25.927ms 
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  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 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.040ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        1.112ms 
 1:  karsolink-01.net.karsolink.com                        0.750ms 
 2:  2a12:d8c0:109f:121::a1                                0.661ms 
 3:  2a12:d8c0:101f:6::1                                  10.219ms 
 4:  no reply
 5:  e0-35.core1.zag2.he.net                              18.854ms 
 6:  no reply
 7:  e0-35.core1.lju1.he.net                              21.366ms 
 8:  2001:7f8:46::19:8524                                 19.965ms 
 9:  2001:67c:2730:fa::2                                  21.525ms 
10:  2001:67c:2730:ff::ff                                 20.951ms 
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  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]                        0.027ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.801ms 
 1:  fw1-lju.6connect.com                                  0.666ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  1.528ms 
 4:  2a03:a100:0:201:1::1                                  1.833ms pmtu 1500
 4:  2001:7f8:46::19:8524                                  1.732ms 
 5:  2001:67c:2730:fa::2                                   1.236ms 
 6:  2001:67c:2730:ff::ff                                  1.678ms asymm  7 
 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
     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                                  0.851ms 
 2:  2a01:260:1::225                                       8.344ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        2.373ms 
 4:  2001:7f8:46::19:8524                                  3.327ms 
 5:  2001:67c:2730:f9::2                                   2.670ms 
 6:  2001:67c:2730:ff::ff                                  3.263ms 
 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
     Too many hops: pmtu 1500
     Resume: pmtu 1500