AS202485 NUBISYSTEM Mathias Giovanni Spadaro trading as NubiSystem

AS overview

Test target: 2a12:de40:34::1 · static prefix probe · address space: PA · prefixes announced: 1

prefix(es): 2a12:de40:34::/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
`2a12:de40:34::1`	prb	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✗	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-

RPKI & ASPA

0 of 1 prefix(es) covered by a valid ROA, 1 not-found.

Prefix	RPKI state	Reason	Covering VRP(s)
`2a12:de40:34::/48`	- not-found	no covering VRP

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

We probed 35 arbitrary IPv6 address(es) inside AS202485's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a07:6d40:1:7::a at hop 10 - that router answers ICMPv6 Echo. This is not in AS202485's announced prefix; operationally it's the AS-edge / peering interface (often on an IXP 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 not honored. Forged ICMPv6 PTB (MTU=1280) had no effect: the next 1500-byte Echo Reply still arrived whole (1460 B, no Fragment Header). PMTUD does not work toward this address from us.
method: ICMPv6 Echo + forged PTB, tested 2026-09-23T12:09:17Z

Failure detail - what to grep in your logs

vantage	our source	your target	method	result	tested (UTC)
belgrade	`2a09:ab81::91`	`2a12:de40:34::1`	`icmp6-echo`	not_honored	2026-09-23T12:09:17Z
berlin	`2a06:d1c1:10b::cccc`	`2a12:de40:34::1`	`icmp6-echo`	not_honored	2026-09-23T12:09:15Z
duseldorf	`2a06:d1c1:10d::aaaa`	`2a12:de40:34::1`	`icmp6-echo`	not_honored	2026-09-23T12:09:14Z
go6lab	`2a00:8642:42::75`	`2a12:de40:34::1`	`icmp6-echo`	not_honored	2026-09-23T12:11:16Z
karsolink	`2a12:d8c0:105a:9001::a154`	`2a12:de40:34::1`	`icmp6-echo`	not_honored	2026-09-23T12:09:15Z
odin	`2607:fae0:a000::42`	`2a12:de40:34::1`	`icmp6-echo`	not_honored	2026-09-23T12:09:15Z
t2	`2a01:261:313:b814:2a0:98ff:fe5b:13e4`	`2a12:de40:34::1`	`icmp6-echo`	not_honored	2026-09-23T12:09:16Z

Attempt log (belgrade):

icmp6-echo → not_honored (reply shrank 1460→1460 B)
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 → not_honored (reply shrank 1460→1460 B)
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 → not_honored (reply shrank 1460→1460 B)
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 → not_honored (reply shrank 1260→1260 B)
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 → not_honored (reply shrank 1460→1460 B)
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 → not_honored (reply shrank 1460→1460 B)
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 → not_honored (reply shrank 1460→1460 B)
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.

What does "Type 2 not honored" actually mean? - click to expand

What this test does

Using the icmp6-echo method, we send a 1500-byte ICMPv6 Echo Request, then a forged ICMPv6 Type 2 (Packet Too Big) declaring path MTU=1280, and observe whether the next Echo Reply arrives split into IPv6 fragments. RFC 4890 requires hosts and intermediate networks not to filter ICMPv6 Type 2; the destination's TCP/UDP stack must act on a received PTB by lowering its Path MTU cache for that destination, which makes subsequent segments smaller.

What we measured

The TCP segment size your server emitted before our forged Type 2 was 1460 B; after, it was 1460 B. No change. RFC 4890 ("Type 2 messages MUST NOT be filtered") expects subsequent segments to shrink to fit a Path MTU of 1280 B.

Three plausible causes

Your host firewall is dropping ICMPv6 Type 2 inbound. Many default firewall rule sets only allow Echo Request/Reply and Neighbor Discovery, silently dropping all other ICMPv6 types - including Packet Too Big.
An upstream / transit network is dropping ICMPv6 Type 2 before it reaches you. Some transit ASes filter ICMPv6 messages other than Echo at the edge. The forged PTB never arrives, so your stack never has a chance to act on it.
Your kernel is ignoring the PTB. Linux / BSD stacks normally accept ICMPv6 PTB and update the route cache, but a few sysctls (or a hardened kernel) can be configured to ignore PMTU updates - typically as part of an over-aggressive anti-spoofing or uRPF policy.

How to check & fix (Linux examples)

1. Confirm Type 2 is not blocked at the host firewall:

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

If you see rules dropping ICMPv6 unconditionally, change them to permit at least icmpv6 type packet-too-big (and destination-unreachable, time-exceeded, parameter-problem per RFC 4890).

2. Confirm the kernel accepts incoming PTB:

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

The defaults (accept_redirects=1, ip_no_pmtu_disc=0) are the right values for honoring PTB.

3. Live trace: while we have an open TCP flow with a small MSS (we run our test from 2607:fae0:a000::42 on odin, 2a00:8642:42::75 on go6lab, 2a12:d8c0:105a:9001::a154 on karsolink, 2a09:ab81::91 on belgrade, 2a01:261:313:b814:2a0:98ff:fe5b:13e4 on t2, 2a06:d1c1:10a::bbbb on amsterdam, 2a06:d1c1:10d::aaaa on duseldorf and 2a06:d1c1:10b::cccc on berlin), watch for our forged Type 2 arriving on your interface:

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)'

If you see our PTBs arriving but TCP segments still stay big, the drop is in your kernel or NIC offload (cause 3). If you don't see them at all, the drop is upstream of you (cause 2) - ask your upstream(s) to permit ICMPv6 Type 2.

4. If your test target above (2026-09-23T12:09:17Z) is a host that you don't own (e.g. a third-party DNS / TLS server you happen to operate prefixes for), the verdict reflects that specific host's behaviour - try the test against a server you do own and we'll happily re-run.

RFC 4890 references: §4.3.1 (Packet Too Big - MUST NOT be dropped), and RFC 8201 for the broader PMTUD requirement.

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

3/4

Echo small (56B) 33.9ms

4/4

Echo 1500B (DF) 33.8ms

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	2a09:ab81::1	0.5ms	0%*	AS60733	PERKE-NET - ZORAN PEROVIC trading as Agencija Perke.NET, RS
2	sox-pn.sox.rs 2001:7f8:1e:8::3a	0.2ms	0%	AS13004	SOX - Serbian Open Exchange DOO, RS
3	e0-33.core2.beg1.he.net 2001:470:1:6e5::1	1.2ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
4	e0-34.core2.bts1.he.net 2001:470:0:33f::2	8.4ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
5	100ge0-0-0-2.core1.vie1.he.net 2001:470:0:412::1	11.4ms	70%	AS6939	HURRICANE - Hurricane Electric LLC, US
6	be3.core1.prg1.he.net 2001:470:e:a7::1	16.7ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
7	*	-	50%	-
8	be2.core3.ams1.he.net 2001:470:e:38::1	26.6ms	10%	AS6939	HURRICANE - Hurricane Electric LLC, US
9	2001:7f8:8f::a504:9581:1	31.1ms	0%	-	NA
10	*	-	50%	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-

Rate-limited ICMPv6: hop 5, hop 7, hop 8, hop 10 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.011ms pmtu 1500
 1:  _gateway                                              0.657ms 
 1:  _gateway                                              0.662ms 
 2:  sox-pn.sox.rs                                         0.543ms 
 3:  e0-33.core2.beg1.he.net                               0.994ms 
 4:  e0-34.core2.bts1.he.net                               9.361ms 
 5:  100ge0-0-0-2.core1.vie1.he.net                       11.095ms 
 6:  be3.core1.prg1.he.net                                15.981ms 
 7:  be8.core4.fra1.he.net                                22.407ms 
 8:  be2.core3.ams1.he.net                                26.487ms 
 9:  2001:7f8:8f::a504:9581:1                             36.055ms asymm  7 
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

3/4

Echo small (56B) 16.1ms

3/4

Echo 1500B (DF) 19.0ms

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	0.3ms	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	0.8ms	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	8.5ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
6	ae0-20.cr10.dus04.lwlcom.net 2a00:c380:b200:230::139	8.4ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
7	ae0-10.cr10.dus01.lwlcom.net 2a00:c380:b200:230::187	8.5ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
8	ae6-60.cr10.ams01.lwlcom.net 2a00:c380:b200:230::213	11.3ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
9	2a00:c380:f000::1f	12.0ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
10	ae0.3009.core01.eyg.as44592.net 2a07:6d40:1:7::a	57.6ms	0%	AS44592	SkyLink - SkyLink Data Center BV, NL
11	*	-	10%	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-

Rate-limited ICMPv6: hop 11 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.023ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.760ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.433ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.932ms 
 3:  ae0-10.cr10.ber03.lwlcom.net                          1.319ms 
 4:  ae0-15.cr11.dtm01.lwlcom.net                          9.179ms asymm  5 
 5:  ae0-20.cr10.dtm01.lwlcom.net                          8.765ms asymm  4 
 6:  ae0-50.cr10.dus02.lwlcom.net                          8.573ms asymm  3 
 7:  ae0-10.cr10.dus01.lwlcom.net                          8.804ms asymm  4 
 8:  ae6-60.cr10.ams01.lwlcom.net                         11.634ms asymm  5 
 9:  2a00:c380:f000::1f                                   12.510ms asymm  6 
10:  ae0.3009.core01.eyg.as44592.net                      15.767ms asymm  7 
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

2/4

Echo small (56B) 9.9ms

3/4

Echo 1500B (DF) 10.6ms

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	5.0ms	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	lag0-vl1010.core1-ams-ni.bb.wiit.network 2001:4ba0:ffe9:153::3	3.9ms	0%	AS24961	MYLOC-AS - WIIT AG, DE
6	2001:7f8:12a::81	7.5ms	0%	-	NA
7	*	-	20%	-
8	*	-	-	-
9	*	-	-	-
10	*	-	-	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-

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

tracepath -6

 1?: [LOCALHOST]                        0.021ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.280ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.778ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            6.843ms 
 3:  no reply
 4:  lag11.core3-dus1.bb.wiit.network                      0.433ms 
 5:  lag0-vl1010.core1-ams-ni.bb.wiit.network              3.950ms 
 6:  2001:7f8:12a::81                                      7.815ms 
 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

From NL host (go6lab) openRFC 4890 ✗

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

4/4

Echo small (56B) 89.3ms

4/4

Echo 1500B (DF) 84.6ms

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	2a00:8642:42::2	2.6ms	0%	AS203993	GNA-DC1-AS - S.J.M. Steffann, NL
2	gw.friends.steffann.nl 2a00:8642:1000:f000::1	3.5ms	-	AS203993	GNA-DC1-AS - S.J.M. Steffann, NL
3	speed-ix.tube-hosting.com 2001:7f8:b7::a504:9581:1	7.0ms	10%	-	NA
4	*	-	0%	-
5	*	-	-	-
6	*	-	-	-
7	*	-	-	-
8	*	-	-	-
9	*	-	-	-
10	*	-	-	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-

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

tracepath -6

 1?: [LOCALHOST]                        0.069ms pmtu 1500
 1:  2a00:8642:42::2                                       3.284ms 
 1:  2a00:8642:42::2                                       3.213ms 
 2:  gw.friends.steffann.nl                               11.624ms 
 3:  speed-ix.tube-hosting.com                            67.993ms 
 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
16:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500

From ITA host (Karsolink) echo onlyRFC 4890 ✗

filter likely at: unknown · min PMTU on path: 1500

3/4

Echo small (56B) 33.8ms

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	2a12:d8c0:109f:121::a1	0.4ms	0%*	AS204471	KARSOLINK - 2S Computers SRL, IT
3	2a12:d8c0:101f:6::1	10.0ms	-	AS204471	KARSOLINK - 2S Computers SRL, IT
4	*	-	-	-
5	be47.core1.mil2.he.net 2001:470:e:69::2	11.8ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
6	be1.core1.zrh2.he.net 2001:470:e:dd::2	163.6ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
7	be10.core4.fra1.he.net 2001:470:e:153::1	18.3ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
8	be2.core3.ams1.he.net 2001:470:e:38::1	25.1ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
9	2001:7f8:8f::a504:9581:1	28.0ms	0%	-	NA
10	*	-	0%	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.030ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.936ms 
 2:  no reply
 3:  2a12:d8c0:101f:103::1                                 9.620ms 
 4:  no reply
 5:  be47.core1.mil2.he.net                               12.053ms 
 6:  be1.core1.zrh2.he.net                                15.764ms 
 7:  be10.core4.fra1.he.net                               19.418ms 
 8:  be2.core3.ams1.he.net                                26.013ms 
 9:  2001:7f8:8f::a504:9581:1                             28.752ms asymm  6 
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 SLO host (6connect) openRFC 4890 ✗

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

4/4

Echo small (56B) 30.4ms

4/4

Echo 1500B (DF) 33.3ms

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	*	-	-	-
3	2a03:a100:0:201:1::1	0.6ms	0%	AS56635	XENYA - XENYA inzeniring, proizvodnja in trgovina, d.o.o. Ljubljana, SI
4	e0-1.core1.lju1.he.net 2001:470:1:5be::1	3.8ms	10%	AS6939	HURRICANE - Hurricane Electric LLC, US
5	100ge0-0-0-5.core1.vie1.he.net 2001:470:0:578::1	8.6ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
6	be3.core1.prg1.he.net 2001:470:e:a7::1	14.0ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
7	be8.core4.fra1.he.net 2001:470:e:1e::1	18.3ms	40%	AS6939	HURRICANE - Hurricane Electric LLC, US
8	be2.core3.ams1.he.net 2001:470:e:38::1	24.5ms	10%	AS6939	HURRICANE - Hurricane Electric LLC, US
9	2001:7f8:8f::a504:9581:1	28.1ms	0%	-	NA
10	*	-	0%	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-

Rate-limited ICMPv6: hop 4, hop 7, hop 8 (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                                  0.708ms 
 1:  fw1-lju.6connect.com                                  0.665ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  0.969ms 
 4:  2a03:a100:0:201:1::1                                  1.028ms pmtu 1500
 4:  e0-1.core1.lju1.he.net                                2.100ms 
 5:  100ge0-0-0-5.core1.vie1.he.net                        8.412ms 
 6:  be3.core1.prg1.he.net                                12.399ms 
 7:  be8.core4.fra1.he.net                                18.363ms 
 8:  be2.core3.ams1.he.net                                24.745ms 
 9:  2001:7f8:8f::a504:9581:1                             28.247ms asymm 12 
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

3/4

Echo small (56B) 38.1ms

3/4

Echo 1500B (DF) 40.0ms

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	6.4ms	0%*	AS34779	T-2-AS - T-2, d.o.o., SI
3	2a01-260-1-1--9c.core6.t-2.net 2a01:260:1:1::9c	2.3ms	0%*	AS34779	T-2-AS - T-2, d.o.o., SI
4	2a01-260-1-1--38.core6.t-2.net 2a01:260:1:1::38	1.8ms	0%*	AS34779	T-2-AS - T-2, d.o.o., SI
5	100ge0-0-0-31.core1.vie1.he.net 2001:470:0:4a8::1	11.0ms	-	AS6939	HURRICANE - Hurricane Electric LLC, US
6	be3.core1.prg1.he.net 2001:470:e:a7::1	14.9ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
7	be3.core1.prg1.he.net 2001:470:e:a7::1	16.5ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
8	be2.core3.ams1.he.net 2001:470:e:38::1	30.6ms	30%	AS6939	HURRICANE - Hurricane Electric LLC, US
9	2001:7f8:8f::a504:9581:1	36.7ms	10%	-	NA
10	*	-	0%	-
11	*	-	30%	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-

Rate-limited ICMPv6: hop 8, hop 9, hop 11 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.025ms pmtu 1500
 1:  no reply
 2:  2a01:260:1::225                                       9.997ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        2.604ms 
 4:  2a01-260-1-1--38.core6.t-2.net                        2.152ms asymm  3 
 5:  100ge0-0-0-31.core1.vie1.he.net                      11.587ms 
 6:  be3.core1.prg1.he.net                                16.886ms 
 7:  be8.core4.fra1.he.net                                36.941ms 
 8:  be2.core3.ams1.he.net                                34.031ms asymm  6 
 9:  2001:7f8:8f::a504:9581:1                             37.719ms asymm  7 
10:  2001:7f8:8f::a504:9581:1                             38.142ms asymm  7 
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