AS209209 FABNET-AS Fabrizio Lanotte

AS overview

Test target: 2a11:fe80:fab3::ffff · static prefix probe · address space: PA · prefixes announced: 2

prefix(es): 2a11:fe80::/32, 2a11:fe80:fab3::/48

Targets & per-vantage-point probe results (1 target(s) across 7 vantage point(s))

Source codes (hover any badge for full description): CUR=curated · NS/SOA/MX=DNS records · SPF=SPF TXT · DRV=holder-derived (www, ns1, mail, gw, …) · ATL=RIPE Atlas · PDB=PeeringDB · WHOIS=RIPE whois · RDAP=RIPE RDAP · HIT=IPv6 Hitlist · RTR=in-prefix path hop (router) · PRB=static prefix probe · SYN=synthetic prefix::1 fallback

Target IP / hostname	Source	SRB host (SOX, Belgrade)					DE host (Berlin)					DE host (Düsseldorf)					NL host (go6lab)					ITA host (Karsolink)					SLO host (6connect)					SLO host (T-2)
Target IP / hostname	Source	ping	1500B	:80	:443	reached	ping	1500B	:80	:443	reached	ping	1500B	:80	:443	reached	ping	1500B	:80	:443	reached	ping	1500B	:80	:443	reached	ping	1500B	:80	:443	reached	ping	1500B	:80	:443	reached
`2a11:fe80:fab3::ffff`	prb	✗	✗	?	?	-	✗	✗	?	?	-	✗	✗	?	?	-	✗	✗	?	?	-	✗	✗	?	?	-	✗	✗	?	?	-	✗	✗	?	?	-

RPKI & ASPA

2 of 2 prefix(es) covered by a valid ROA.

Prefix	RPKI state	Reason	Covering VRP(s)
`2a11:fe80::/32`	✓ valid	matched VRP (correct origin, length within maxLength)	AS209209 /32 maxLen 48 (ripe)
`2a11:fe80:fab3::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS209209 /48 maxLen 48 (ripe); AS209209 /32 maxLen 48 (ripe)

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

At least one router inside AS209209's announced prefix replied during the random-target probe. Hop(s): 2a11:fe80:46::, 2a11:fe80:49::. These are candidate targets for direct testing.

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 2026-09-23T12:08:55Z

Failure detail - what to grep in your logs

vantage	our source	your target	method	result	tested (UTC)
belgrade	`2a09:ab81::91`	`2a11:fe80:fab3::ffff`	`icmp6-echo`	no_echo	2026-09-23T12:08:55Z
berlin	`2a06:d1c1:10b::cccc`	`2a11:fe80:fab3::ffff`	`icmp6-echo`	no_echo	2026-09-23T12:08:53Z
duseldorf	`2a06:d1c1:10d::aaaa`	`2a11:fe80:fab3::ffff`	`icmp6-echo`	no_echo	2026-09-23T12:08:53Z
go6lab	`2a00:8642:42::75`	`2a11:fe80:fab3::ffff`	`icmp6-echo`	no_echo	2026-09-23T12:10:43Z
karsolink	`2a12:d8c0:105a:9001::a154`	`2a11:fe80:fab3::ffff`	`icmp6-echo`	no_echo	2026-09-23T12:08:53Z
odin	`2607:fae0:a000::42`	`2a11:fe80:fab3::ffff`	`icmp6-echo`	no_echo	2026-09-23T12:08:52Z
t2	`2a01:261:313:b814:2a0:98ff:fe5b:13e4`	`2a11:fe80:fab3::ffff`	`icmp6-echo`	no_echo	2026-09-23T12:08:54Z

Attempt log (belgrade):

icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
dns-tcp → no_tcp: connect failed: timed out
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (berlin):

icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
dns-tcp → no_tcp: connect failed: timed out
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (duseldorf):

icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
dns-tcp → no_tcp: connect failed: timed out
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (go6lab):

icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
dns-tcp → no_tcp: connect failed: timed out
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (karsolink):

icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
dns-tcp → no_tcp: connect failed: timed out
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (odin):

icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
dns-tcp → no_tcp: connect failed: timed out
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (t2):

icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
dns-tcp → no_tcp: connect failed: timed out
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

To match the corresponding ICMPv6 packet on your side (host firewall, AS edge, or transit tap), look for our PTBs around the timestamps above:

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)'

If you see our PTBs arriving but the destination's TCP/Echo flow does not shrink, the drop is in the destination kernel (cause 3 below). If you don't see them at all, drop is upstream of you (cause 2). If you only see them from some of our source IPs but not others, the drop is path-asymmetric - at least one transit on the differing route is filtering.

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: before path completes · min PMTU on path: 1420

0/4

Echo small (56B) -

0/4

Echo 1500B (DF) -

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	2a09:ab81::1	0.4ms	0%*	AS60733	PERKE-NET - ZORAN PEROVIC trading as Agencija Perke.NET, RS
2	sox-pn.sox.rs 2001:7f8:1e:8::3a	0.5ms	0%	AS13004	SOX - Serbian Open Exchange DOO, RS
3	2001:7f8:1e:8::3d	0.4ms	0%	AS13004	SOX - Serbian Open Exchange DOO, RS
4	2001:67c:128c::699	19.5ms	0%	-	NA
5	*	-	-	-
6	*	-	-	-
7	*	-	-	-
8	*	-	-	-
9	*	-	-	-
10	*	-	-	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.011ms pmtu 1500
 1:  _gateway                                              0.465ms 
 1:  _gateway                                              0.406ms 
 2:  sox-pn.sox.rs                                         0.633ms 
 3:  2001:7f8:1e:8::3d                                     0.803ms asymm  2 
 4:  2001:67c:128c::699                                   17.067ms 
 5:  stockholm.as209209.net                               61.625ms pmtu 1420
 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
18:  no reply
     Too many hops: pmtu 1420

From DE host (Berlin) all blocked

filter likely at: before path completes · min PMTU on path: 1420

0/4

Echo small (56B) -

0/4

Echo 1500B (DF) -

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	xe-0-0-13-178.gw01.ber01.as59645.net 2a06:d1c1:100:b::1	0.2ms	0%*	AS59645	WYBT-NET - Tobias Fiebig, DE
2	ae0-2453.cr10.ber01.lwlcom.net 2a06:d1c0::dead:beef:1c02	0.6ms	0%*	AS59645	WYBT-NET - Tobias Fiebig, DE
3	ae0-10.cr10.ber03.lwlcom.net 2a00:c380:b200:230::220	0.6ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
4	ae0-15.cr11.dtm01.lwlcom.net 2a00:c380:b200:230::5	8.4ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
5	ae0-10.cr10.dtm02.lwlcom.net 2a00:c380:b200:230::255	8.4ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
6	ae0-20.cr10.dus04.lwlcom.net 2a00:c380:b200:230::139	8.6ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
7	ae0-20.cr10.dus01.lwlcom.net 2a00:c380:b200:230::108	8.4ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
8	ae0-90.cr11.dus01.lwlcom.net 2a00:c380:b200:230::222	8.5ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
9	as41692.dusseldorf.megaport.com 2001:7f8:8::a2dc:0:1	8.5ms	0%	-	NA
10	2001:7f8:3a:e106::2	8.7ms	0%	AS41692	OPENCARRIER-AS - OpenCarrier eG, DE
11	2a00:f70:abcd:143::4	8.7ms	0%	AS30962	COMTRANCE-AS - comtrance service GmbH, DE
12	2a11:fe80:49	8.9ms	0%	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.024ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.600ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.596ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        1.031ms 
 3:  ae0-10.cr10.ber03.lwlcom.net                          1.103ms 
 4:  ae0-15.cr11.dtm01.lwlcom.net                          8.838ms asymm  5 
 5:  ae0-20.cr10.dtm01.lwlcom.net                          8.845ms asymm  4 
 6:  ae0-20.cr10.dus04.lwlcom.net                          8.953ms asymm  5 
 7:  ae0-10.cr10.dus01.lwlcom.net                          8.925ms asymm  4 
 8:  ae0-90.cr11.dus01.lwlcom.net                          9.130ms asymm  5 
 9:  as41692.dusseldorf.megaport.com                      10.669ms asymm  3 
10:  2001:7f8:3a:e106::2                                   9.478ms asymm  4 
11:  2a00:f70:abcd:143::4                                  9.695ms asymm  5 
12:  dusseldorf.as209209.net                               9.446ms asymm  6 
13:  dusseldorf.as209209.net                               9.451ms pmtu 1420
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply
     Too many hops: pmtu 1420

From DE host (Düsseldorf) all blocked

filter likely at: before path completes · min PMTU on path: 1420

0/4

Echo small (56B) -

0/4

Echo 1500B (DF) -

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	xe-0-0-12-142.gw01.dus01.as59645.net 2a06:d1c1:100:d::1	0.2ms	0%*	AS59645	WYBT-NET - Tobias Fiebig, DE
2	eth1-0-12-h5594.edge5-dus1.bb.wiit.network 2001:4ba0:92f4:3::1	1.0ms	0%	AS24961	MYLOC-AS - WIIT AG, DE
3	*	-	-	-
4	lag30.core3-dus1.bb.wiit.network 2001:4ba0:ffe9:109::2	0.3ms	0%	AS24961	MYLOC-AS - WIIT AG, DE
5	ddf-b4-link.ip.twelve99.net 2001:2035:0:9fb::1	0.6ms	0%	AS1299	TWELVE99 - Arelion Sweden AB, SE
6	ddf-b5-link.ip.twelve99.net 2001:2034:a:336::1	2.8ms	0%	AS1299	TWELVE99 - Arelion Sweden AB, SE
7	2001:2034:a:1d9	20.6ms	60%	-
8	*	-	-	-
9	sto-b9-link.ip.twelve99.net 2001:2034:a:177::1	21.9ms	0%	AS1299	TWELVE99 - Arelion Sweden AB, SE
10	constantcompany-ic-370147.ip.twelve99-cust.net 2001:2035:0:128c::2	23.9ms	0%	AS1299	TWELVE99 - Arelion Sweden AB, SE
11	constantcompany-ic-370147.ip.twelve99-cust.net 2001:2035:0:128c::2	24.0ms	-	AS1299	TWELVE99 - Arelion Sweden AB, SE
12	*	-	-	-
13	2a05:f480:2000:425::33	23.0ms	0%	AS20473	AS-VULTR - The Constant Company, LLC, US
14	2a11:fe80:46	23.0ms	0%	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-

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

tracepath -6

 1?: [LOCALHOST]                        0.024ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.339ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.395ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            1.404ms 
 3:  no reply
 4:  lag30.core3-dus1.bb.wiit.network                      0.399ms 
 5:  ddf-b4-link.ip.twelve99.net                           0.823ms 
 6:  ddf-b5-link.ip.twelve99.net                           3.176ms 
 7:  hbg-bb2-link.ip.twelve99.net                         20.800ms asymm  6 
 8:  no reply
 9:  sto-b9-link.ip.twelve99.net                          22.400ms asymm  6 
10:  constantcompany-ic-370147.ip.twelve99-cust.net       59.441ms asymm  9 
11:  no reply
12:  no reply
13:  2a05:f480:2000:425::33                               23.361ms asymm 11 
14:  2a05:f480:2000:425::33                               23.272ms asymm 11 
15:  stockholm.as209209.net                               23.370ms asymm 13 
16:  stockholm.as209209.net                               23.153ms pmtu 1420
16:  no reply
17:  no reply
18:  no reply
     Too many hops: pmtu 1420

From NL host (go6lab) all blocked

filter likely at: before path completes · min PMTU on path: 1420

0/4

Echo small (56B) -

0/4

Echo 1500B (DF) -

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	2a00:8642:42::2	2.1ms	0%	AS203993	GNA-DC1-AS - S.J.M. Steffann, NL
2	gw.friends.steffann.nl 2a00:8642:1000:f000::1	2.8ms	0%*	AS203993	GNA-DC1-AS - S.J.M. Steffann, NL
3	2a00:1ca8:1::194	5.1ms	0%	AS50673	Serverius-as - Serverius Holding B.V., NL
4	2a03:3f40::10:33	8.0ms	0%	AS50673	Serverius-as - Serverius Holding B.V., NL
5	2001:7f8:1::a504:1692:1	19.6ms	0%	-	NA
6	oc-r1-ams2.r1.dus1.de.opencarrier.eu 2001:7f8:3a:e001::1	14.6ms	0%	AS41692	OPENCARRIER-AS - OpenCarrier eG, DE
7	2001:7f8:3a:e106::2	13.4ms	0%	AS41692	OPENCARRIER-AS - OpenCarrier eG, DE
8	2a00:f70:abcd:143::4	19.2ms	0%	AS30962	COMTRANCE-AS - comtrance service GmbH, DE
9	2a11:fe80:49	16.0ms	0%	-
10	*	-	-	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.034ms pmtu 1420
 1:  2a00:8642:42::2                                       2.133ms 
 1:  2a00:8642:42::2                                       3.509ms 
 2:  no reply
 3:  2a00:1ca8:1::194                                      8.045ms 
 4:  2a03:3f40::10:33                                      8.011ms 
 5:  2001:7f8:1::a504:1692:1                              19.946ms 
 6:  oc-r1-ams2.r1.dus1.de.opencarrier.eu                 14.089ms asymm  7 
 7:  2001:7f8:3a:e106::2                                  14.128ms asymm  8 
 8:  2a00:f70:abcd:143::4                                 14.817ms asymm  9 
 9:  dusseldorf.as209209.net                              14.593ms asymm 10 
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply
     Too many hops: pmtu 1420
     Resume: pmtu 1420

From ITA host (Karsolink) all blocked

filter likely at: before path completes · min PMTU on path: 1420

0/4

Echo small (56B) -

0/4

Echo 1500B (DF) -

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	karsolink-01.net.karsolink.com 2a12:d8c0:105a:9001::1	0.4ms	0%*	AS204471	KARSOLINK - 2S Computers SRL, IT
2	*	-	-	-
3	2a12:d8c0:109f:106::a2	3.1ms	-	AS204471	KARSOLINK - 2S Computers SRL, IT
4	2a02:2d8:1:b80d:232a	7.7ms	0%	-
5	ae1-360.cr7-mil2.ip6.gtt.net 2001:668:0:3:ffff:1:0:3555	9.2ms	0%	AS3257	GTT-BACKBONE - GTT Communications Inc., US
6	2001:668:0:2:ffff:0:8d88:6e62	40.9ms	0%	AS3257	GTT-BACKBONE - GTT Communications Inc., US
7	2001:668:0:2:ffff:0:8d88:6e62	40.8ms	0%	AS3257	GTT-BACKBONE - GTT Communications Inc., US
8	2001:668:0:3:ffff:1:0:18ca	40.5ms	-	AS3257	GTT-BACKBONE - GTT Communications Inc., US
9	*	-	-	-
10	2a05:f480:2000:425::33	40.8ms	0%	AS20473	AS-VULTR - The Constant Company, LLC, US
11	2a11:fe80:46	47.9ms	0%	-
12	2a11:fe80:46	47.1ms	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.039ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.849ms 
 1:  no reply
 2:  no reply
 3:  2a12:d8c0:109f:106::a2                                3.667ms 
 4:  ae0-303.rt.vsx.pda.it.retn.net                        3.794ms 
 5:  ae1-360.cr7-mil2.ip6.gtt.net                          9.879ms asymm  6 
 6:  ae20.cr3-vie2.ip6.gtt.net                            40.089ms asymm  9 
 7:  2001:668:0:3:ffff:1:0:18ca                           42.068ms 
 8:  2001:668:0:3:ffff:1:0:18ca                           43.481ms asymm  7 
 9:  no reply
10:  2a05:f480:2000:425::33                               41.516ms asymm 11 
11:  2a05:f480:2000:425::33                               42.607ms 
12:  stockholm.as209209.net                               47.257ms asymm  7 
13:  stockholm.as209209.net                               48.027ms pmtu 1420
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply
     Too many hops: pmtu 1420

From SLO host (6connect) all blocked

filter likely at: before path completes · min PMTU on path: 1420

0/4

Echo small (56B) -

0/4

Echo 1500B (DF) -

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	fw1-lju.6connect.com 2607:fae0:a000::2	0.4ms	0%*	AS8038	6CONNECT - 6connect, Inc., US
2	*	-	0%*	-
3	2a03:a100:0:201:1::1	0.7ms	0%	AS56635	XENYA - XENYA inzeniring, proizvodnja in trgovina, d.o.o. Ljubljana, SI
4	*	-	90%	-
5	100ge0-0-0-5.core1.vie1.he.net 2001:470:0:578::1	7.9ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
6	be3.core1.prg1.he.net 2001:470:e:a7::1	11.8ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
7	*	-	20%	-
8	be3.core1.sto1.he.net 2001:470:0:335::2	35.9ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
9	2001:7f8:3e:0:a500:2:473:1	48.7ms	0%	-	NA
10	ethernetae8-sr2.sto1.constant.com 2001:19f0:fc00::a54:11e	32.1ms	0%	-	NA
11	ethernetswp56-ds1-u2-r102-a.sto1.constant.com 2001:19f0:fc00::a55:62	31.7ms	0%	-	NA
12	2a05:f480:2000:425::33	31.5ms	0%	AS20473	AS-VULTR - The Constant Company, LLC, US
13	2a11:fe80:46	31.7ms	0%	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-

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

tracepath -6

 1?: [LOCALHOST]                        0.017ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.723ms 
 1:  fw1-lju.6connect.com                                  0.674ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  0.987ms 
 4:  2a03:a100:0:201:1::1                                  0.827ms pmtu 1500
 4:  e0-1.core1.lju1.he.net                                2.180ms 
 5:  100ge0-0-0-5.core1.vie1.he.net                        7.404ms 
 6:  be3.core1.prg1.he.net                                14.183ms 
 7:  be8.core4.fra1.he.net                                18.853ms 
 8:  be9.core1.sto1.he.net                                37.034ms 
 9:  2001:7f8:3e:0:a500:2:473:1                           32.522ms asymm 13 
10:  ethernetae8-sr1.sto1.constant.com                    32.548ms asymm 13 
11:  ethernetswp56-ds1-u2-r102-a.sto1.constant.com        31.891ms asymm 15 
12:  2a05:f480:2000:425::33                               31.840ms asymm 16 
13:  stockholm.as209209.net                               31.817ms asymm 17 
14:  stockholm.as209209.net                               31.758ms pmtu 1420
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply

From SLO host (T-2) all blocked

filter likely at: past AS20473 (AS-VULTR) · min PMTU on path: 1420

0/4

Echo small (56B) -

0/4

Echo 1500B (DF) -

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	*	-	0%*	-
2	2a01:260:1::225	9.9ms	0%*	AS34779	T-2-AS - T-2, d.o.o., SI
3	2a01-260-1-1--9a.core6.t-2.net 2a01:260:1:1::9a	2.5ms	0%*	AS34779	T-2-AS - T-2, d.o.o., SI
4	hurricane-electric.nikhef.nlsix.net 2001:7f8:13::a500:6939:1	39.0ms	0%*	-	NA
5	*	-	0%	-
6	be47.core3.ams1.he.net 2001:470:e:12::2	38.0ms	-	AS6939	HURRICANE - Hurricane Electric LLC, US
7	be7.core1.cph1.he.net 2001:470:e:74::2	46.3ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
8	100ge0-0-0-22.core1.sto1.he.net 2001:470:0:2b1::2	49.1ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
9	be2.core1.sto1.he.net 2001:470:e:5f::2	53.7ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
10	2001:7f8:3e:0:a500:2:473:1	46.8ms	10%	-	NA
11	ethernetswp56-ds1-u2-r102-b.sto1.constant.com 2001:19f0:fc00::a55:66	46.2ms	0%	-	NA
12	ethernetswp55-ds1-u2-r102-b.sto1.constant.com 2001:19f0:fc00::a55:4a	42.5ms	0%	-	NA
13	2a05:f480:2000:425::33	45.6ms	0%	AS20473	AS-VULTR - The Constant Company, LLC, US
14	*	-	0%	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-

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

tracepath -6

 1?: [LOCALHOST]                        0.016ms pmtu 1500
 1:  no reply
 2:  2a01:260:1::225                                       3.753ms 
 3:  2a01-260-1-1--9c.core6.t-2.net                        3.448ms 
 4:  hurricane-electric.nikhef.nlsix.net                  39.321ms 
 5:  hurricane-electric.nikhef.nlsix.net                  39.091ms asymm  4 
 6:  be47.core3.ams1.he.net                               37.896ms 
 7:  be47.core3.ams1.he.net                               32.247ms asymm  6 
 8:  be7.core1.cph1.he.net                                49.242ms asymm  6 
 9:  be2.core1.sto1.he.net                                50.142ms asymm  7 
10:  ethernetae8-sr2.sto1.constant.com                    58.132ms asymm 11 
11:  ethernetswp55-ds1-u2-r102-b.sto1.constant.com        42.670ms asymm 12 
12:  2a05:f480:2000:425::33                               45.490ms asymm 14 
13:  stockholm.as209209.net                               47.651ms asymm 15 
14:  stockholm.as209209.net                               48.437ms pmtu 1420
14:  stockholm.as209209.net                               47.179ms asymm 15 
15:  no reply
16:  no reply
17:  no reply
18:  no reply
     Too many hops: pmtu 1420
     Resume: pmtu 1420