AS12577 MMC-AT-AS MMC GmbH

AS overview

Test target: 2a00:1618:1::1 · ns1.mmc.at · address space: PA · prefixes announced: 1

prefix(es): 2a00:1618::/29

Targets & per-vantage-point probe results (3 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
`2a00:1618:1::1` ns1.mmc.at	NS	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-
`2a00:1618:2::1` ns2.mmc.at	NS	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-	✓	✓	?	?	-
`2a00:1618:ffff:803::5` mmc.at	drv	✓	✓	open	open	-	✓	✓	open	open	-	✓	✓	open	open	-	✓	✓	open	open	-	✓	✓	open	open	-	✓	✓	open	open	-	✓	✓	open	open	-

VIX / AAIX / SAIX / TIROL-IX / ERA-IX peering

VIX / AAIX / SAIX / TIROL-IX / ERA-IX member - Open peering, peering member, since 2010-07-29. IPv6 LAN: 2001:7f8:30:0:1:1:1:2577. Locations: -.

RPKI & ASPA

1 of 1 prefix(es) covered by a valid ROA.

Prefix	RPKI state	Reason	Covering VRP(s)
`2a00:1618::/29`	✓ valid	matched VRP (correct origin, length within maxLength)	AS12577 /29 maxLen 29 (ripe)

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

At least one router inside AS12577's announced prefix replied during the random-target probe. Hop(s): 2a00:1618:ffff:850::4, 2a00:1618:ffff:852::2, 2a00:1618:ffff:853::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 honored. Forged PTB accepted; next response shrunk. (ICMPv6 Echo + forged PTB)
DE host (Berlin): Type 2 honored. Forged PTB accepted; next response shrunk. (ICMPv6 Echo + forged PTB)
DE host (Düsseldorf): Type 2 honored. Forged PTB accepted; next response shrunk. (ICMPv6 Echo + forged PTB)
NL host (go6lab): inconclusive: no Echo Reply after PTB (probe 1500B). (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 - measurement artifact: One vantage's probe didn't generate enough data to detect segment shrinkage (natural reply too small, or no second response). The other vantage's verdict is the meaningful one.

Failure detail - what to grep in your logs

vantage	our source	your target	method	result	tested (UTC)
belgrade	`2a09:ab81::91`	`2a00:1618:1::1`	`icmp6-echo`	honored	2026-09-24T13:29:42Z
berlin	`2a06:d1c1:10b::cccc`	`2a00:1618:1::1`	`icmp6-echo`	honored	2026-09-24T13:29:42Z
duseldorf	`2a06:d1c1:10d::aaaa`	`2a00:1618:1::1`	`icmp6-echo`	honored	2026-09-24T13:29:44Z
go6lab	`2a00:8642:42::75`	`2a00:1618:1::1`	`icmp6-echo`	inconclusive	2026-09-24T13:30:00Z
karsolink	`2a12:d8c0:105a:9001::a154`	`2a00:1618:1::1`	`icmp6-echo`	honored	2026-09-24T13:29:39Z
odin	`2607:fae0:a000::42`	`2a00:1618:1::1`	`icmp6-echo`	honored	2026-09-24T13:29:45Z
t2	`2a01:261:313:b814:2a0:98ff:fe5b:13e4`	`2a00:1618:1::1`	`icmp6-echo`	honored	2026-09-24T13:29:45Z

Attempt log (belgrade):

icmp6-echo → honored (honored by fragmenting its reply into 2 via the IPv6 Fragment Header, rather than resizing)
dns-tcp → inconclusive (reply 31 B before PTB): max DNS-over-TCP segment 31B; not big enough to test PMTU shrink
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (berlin):

icmp6-echo → honored (honored by fragmenting its reply into 2 via the IPv6 Fragment Header, rather than resizing)
dns-tcp → inconclusive (reply 31 B before PTB): max DNS-over-TCP segment 31B; not big enough to test PMTU shrink
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (duseldorf):

icmp6-echo → honored (honored by fragmenting its reply into 2 via the IPv6 Fragment Header, rather than resizing)
dns-tcp → inconclusive (reply 31 B before PTB): max DNS-over-TCP segment 31B; not big enough to test PMTU shrink
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (go6lab):

icmp6-echo → inconclusive (reply 1460 B before PTB): no Echo Reply after PTB (probe 1500B)
dns-tcp → inconclusive (reply 31 B before PTB): max DNS-over-TCP segment 31B; not big enough to test PMTU shrink
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (karsolink):

icmp6-echo → honored (honored by fragmenting its reply into 2 via the IPv6 Fragment Header, rather than resizing)
dns-tcp → inconclusive (reply 31 B before PTB): max DNS-over-TCP segment 31B; not big enough to test PMTU shrink
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (odin):

icmp6-echo → honored (honored by fragmenting its reply into 2 via the IPv6 Fragment Header, rather than resizing)
dns-tcp → inconclusive (reply 31 B before PTB): max DNS-over-TCP segment 31B; not big enough to test PMTU shrink
tls → no_tcp: TLS connect failed
http → no_tcp: tcp/80 not open

Attempt log (t2):

icmp6-echo → honored (honored by fragmenting its reply into 2 via the IPv6 Fragment Header, rather than resizing)
dns-tcp → inconclusive (reply 31 B before PTB): max DNS-over-TCP segment 31B; not big enough to test PMTU shrink
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.

Where the path divergence is

Per-vantage probe + verdict (headline):

belgrade: probe icmp6-echo → verdict honored
berlin: probe icmp6-echo → verdict honored
duseldorf: probe icmp6-echo → verdict honored
go6lab: probe icmp6-echo → verdict inconclusive
karsolink: probe icmp6-echo → verdict honored
odin: probe icmp6-echo → verdict honored
t2: probe icmp6-echo → verdict honored

Full per-method matrix (all four methods run at each vantage):

vantage	icmp6-echo	dns-tcp	tls	http
belgrade	honored	inconclusive	no_tcp	no_tcp
berlin	honored	inconclusive	no_tcp	no_tcp
duseldorf	honored	inconclusive	no_tcp	no_tcp
go6lab	inconclusive	inconclusive	no_tcp	no_tcp
karsolink	honored	inconclusive	no_tcp	no_tcp
odin	honored	inconclusive	no_tcp	no_tcp
t2	honored	inconclusive	no_tcp	no_tcp

✓ All vantages agree on method(s): icmp6-echo - the headline-method spread above is dispatcher noise, not a real Type 2 disagreement.

These vantage-level disagreements are rooted somewhere in the forward paths. Joining each per-vantage traceroute against the IP→AS lookup from our global yarrp mesh, the first hop where the paths land in different ASes is the most likely site of the offending filter / unreachable AS / Type 2 drop.

Suspect transit ASes (ranked by how often they appear at the divergence point on the path of the worse-classifying vantage): AS12577, AS174, AS201011.

From belgrade (open/Type-2=honored) the path enters an opaque hop at hop 14; from berlin (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (open/Type-2=honored) the path enters an opaque hop at hop 13; from duseldorf (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (open/Type-2=honored) the path enters AS12577 at hop 4; from go6lab (open/Type-2=inconclusive) the same hop is in AS50673. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (open/Type-2=honored) the path enters AS12577 at hop 5; from karsolink (open/Type-2=honored) the same hop is in AS9002. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (open/Type-2=honored) the path enters an opaque hop at hop 7; from odin (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (open/Type-2=honored) the path enters an opaque hop at hop 7; from t2 (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From berlin (open/Type-2=honored) the path enters AS201011 at hop 9; from duseldorf (open/Type-2=honored) the same hop is in AS174. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From berlin (open/Type-2=honored) the path enters AS201011 at hop 8; from go6lab (open/Type-2=inconclusive) the same hop is in AS174. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From berlin (open/Type-2=honored) the path enters AS201011 at hop 8; from karsolink (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From berlin (open/Type-2=honored) the path enters AS201011 at hop 8; from odin (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From berlin (open/Type-2=honored) the path enters AS201011 at hop 8; from t2 (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From duseldorf (open/Type-2=honored) the path enters AS174 at hop 12; from go6lab (open/Type-2=inconclusive) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From duseldorf (open/Type-2=honored) the path enters AS174 at hop 9; from karsolink (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From duseldorf (open/Type-2=honored) the path enters AS174 at hop 9; from odin (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From duseldorf (open/Type-2=honored) the path enters AS174 at hop 9; from t2 (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From go6lab (open/Type-2=inconclusive) the path enters AS174 at hop 5; from karsolink (open/Type-2=honored) the same hop is in AS9002. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From go6lab (open/Type-2=inconclusive) the path enters AS50673 at hop 3; from odin (open/Type-2=honored) the same hop is in AS56635. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.
From go6lab (open/Type-2=inconclusive) the path enters AS174 at hop 7; from t2 (open/Type-2=honored) the same hop is in AS12577. Last common AS: AS12577. The disagreement is most likely rooted in one of those two transit ASes.

Diagnosis is path-level, not packet-level: it tells you which transit AS is the prime suspect, not exactly which firewall rule is to blame. Use the tracepath6 output below (when available) for per-hop PMTU evidence on the same path.

✨ Diagnostic interpretation

An operator-targeted diagnostic interpretation can be generated for this AS on demand. The pipeline holds the raw verdicts and the per-hop walk; an AI pass synthesises where to start looking. Click the button below to run it.

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

4/4

Echo small (56B) 13.9ms

4/4

Echo 1500B (DF) 14.0ms

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	2a09:ab81::1	0.3ms	0%*	AS60733	PERKE-NET - ZORAN PEROVIC trading as Agencija Perke.NET, RS
2	2001:7f8:1e::4	0.4ms	0%	AS13004	SOX - Serbian Open Exchange DOO, RS
3	2001:7f8:30:0:1:1:1:2577 @VIX / AAIX / SAIX / TIROL-IX / ERA-IX	12.7ms	0%	-	NA
4	rr1v850.vix3.mmc.at 2a00:1618:ffff:850::4	11.2ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
5	x2v861.vix2.mmc.at 2a00:1618:ffff:861::7	13.1ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
6	x1v816.hs1.mmc.at 2a00:1618:ffff:816::5	11.2ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
7	*	-	0%	-
8	*	-	-	-
9	*	-	-	-
10	*	-	-	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.011ms pmtu 1500
 1:  _gateway                                              0.339ms 
 1:  _gateway                                              0.496ms 
 2:  2001:7f8:1e::4                                        1.196ms 
 3:  2001:7f8:30:0:1:1:1:2577                             13.007ms 
 4:  rr1v850.vix3.mmc.at                                  13.042ms 
 5:  x2v861.vix2.mmc.at                                   13.366ms 
 6:  x1v816.hs1.mmc.at                                    11.944ms 
 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
19:  no reply
20:  no reply
21:  no reply
22:  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

4/4

Echo small (56B) 21.8ms

4/4

Echo 1500B (DF) 21.9ms

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	0.5ms	0%*	AS59645	WYBT-NET - Tobias Fiebig, DE
3	ae3-90.cr10.ham01.lwlcom.net 2a00:c380:b200:230::192	5.0ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
4	ae0-50.cr11.ham01.lwlcom.net 2a00:c380:b200:230::45	4.9ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
5	2a00:c380:f000::4b	5.1ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
6	ae4-2087.dus10.core-backbone.com 2a01:4a0:0:2087::33	11.3ms	0%	AS201011	CORE-BACKBONE - Core-Backbone GmbH, DE
7	ae21-2071.fra10.core-backbone.com 2a01:4a0:0:2071::4	10.7ms	0%	AS201011	CORE-BACKBONE - Core-Backbone GmbH, DE
8	ae2-2021.fra20.core-backbone.com 2a01:4a0:0:2021::4	10.5ms	0%	AS201011	CORE-BACKBONE - Core-Backbone GmbH, DE
9	ae6-2003.nbg20.core-backbone.com 2a01:4a0:0:2003::2	12.0ms	0%	AS201011	CORE-BACKBONE - Core-Backbone GmbH, DE
10	ae2-2032.muc20.core-backbone.com 2a01:4a0:0:2032::7	14.6ms	0%	AS201011	CORE-BACKBONE - Core-Backbone GmbH, DE
11	ae4-2057.slz10.core-backbone.com 2a01:4a0:0:2057::8	16.1ms	0%	AS201011	CORE-BACKBONE - Core-Backbone GmbH, DE
12	ae2-2058.vie20.core-backbone.com 2a01:4a0:0:2058::16	20.0ms	0%	AS201011	CORE-BACKBONE - Core-Backbone GmbH, DE
13	2a01:4a0:1338:1db::2	20.0ms	0%	AS201011	CORE-BACKBONE - Core-Backbone GmbH, DE
14	rr2v853.vix2.mmc.at 2a00:1618:ffff:853::2	20.9ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
15	x2v861.vix2.mmc.at 2a00:1618:ffff:861::7	20.9ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
16	x1v816.hs1.mmc.at 2a00:1618:ffff:816::5	21.3ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
17	*	-	0%	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.020ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.631ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.391ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.831ms 
 3:  ae3-90.cr10.ham01.lwlcom.net                          5.363ms 
 4:  ae0-50.cr11.ham01.lwlcom.net                          5.327ms 
 5:  2a00:c380:f000::4b                                    5.696ms asymm  4 
 6:  ae4-2087.dus10.core-backbone.com                     11.728ms asymm  5 
 7:  ae21-2071.fra10.core-backbone.com                    11.202ms asymm  5 
 8:  ae2-2021.fra20.core-backbone.com                     10.788ms asymm  4 
 9:  ae6-2003.nbg20.core-backbone.com                     12.245ms asymm  6 
10:  ae2-2032.muc20.core-backbone.com                     14.964ms asymm  7 
11:  ae4-2057.slz10.core-backbone.com                     16.779ms asymm  8 
12:  ae2-2058.vie20.core-backbone.com                     20.274ms asymm  9 
13:  2a01:4a0:1338:1db::2                                 20.631ms asymm 10 
14:  rr2v853.vix2.mmc.at                                  21.306ms asymm  6 
15:  x2v861.vix2.mmc.at                                   21.529ms asymm  7 
16:  x1v816.hs1.mmc.at                                    21.722ms asymm  8 
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  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

4/4

Echo small (56B) 21.4ms

4/4

Echo 1500B (DF) 21.4ms

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	0.1ms	0%*	AS59645	WYBT-NET - Tobias Fiebig, DE
2	eth1-0-12-h5594.edge5-dus1.bb.wiit.network 2001:4ba0:92f4:3::1	2.8ms	0%	AS24961	MYLOC-AS - WIIT AG, DE
3	*	-	-	-
4	lag11.core3-dus1.bb.wiit.network 2001:4ba0:ffe9:115::3	0.2ms	0%	AS24961	MYLOC-AS - WIIT AG, DE
5	lag0-vl1001.core4-dus1.bb.wiit.network 2001:4ba0:ffe9:123::3	0.5ms	0%	AS24961	MYLOC-AS - WIIT AG, DE
6	2001:978:2:6::20	0.8ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
7	be3690.rcr21.dus01.atlas.cogentco.com 2001:550:0:1000::9a19:1021	1.6ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
8	be2361.ccr42.fra05.atlas.cogentco.com 2001:550:0:1000::9a36:3b5d	6.7ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
9	be5516.ccr21.muc03.atlas.cogentco.com 2001:550:0:1000::9a36:3e7a	44.6ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
10	be5456.ccr81.vie01.atlas.cogentco.com 2001:550:0:1000::9a36:48a6	17.0ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
11	be3935.agr61.vie01.atlas.cogentco.com 2001:550:0:1000::9a36:274e	16.1ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
12	br-v6-cogent.mmc.at 2001:978:2::3e:2	15.3ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
13	rr2v852.vix2.mmc.at 2a00:1618:ffff:852::2	20.4ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
14	x1v861.vix3.mmc.at 2a00:1618:ffff:861::6	20.4ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
15	x1v816.hs1.mmc.at 2a00:1618:ffff:816::5	20.7ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
16	*	-	0%	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.033ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.662ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.197ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            8.186ms 
 3:  no reply
 4:  lag30.core3-dus1.bb.wiit.network                      0.356ms 
 5:  lag0-vl1001.core4-dus1.bb.wiit.network                0.485ms 
 6:  2001:978:2:6::20                                      1.052ms 
 7:  be3690.rcr21.dus01.atlas.cogentco.com                 1.862ms 
 8:  be2361.ccr42.fra05.atlas.cogentco.com                 5.020ms asymm  9 
 9:  be5516.ccr21.muc03.atlas.cogentco.com                10.349ms asymm 10 
10:  be5456.ccr81.vie01.atlas.cogentco.com                17.656ms asymm 11 
11:  be4079.agr61.vie01.atlas.cogentco.com                15.883ms asymm 12 
12:  br-v6-cogent.mmc.at                                  15.453ms asymm 13 
13:  rr2v852.vix2.mmc.at                                  20.754ms asymm  7 
14:  x1v861.vix3.mmc.at                                   20.815ms asymm  8 
15:  x1v816.hs1.mmc.at                                    21.012ms asymm  9 
16:  no reply
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500

From NL host (go6lab) open

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

4/4

Echo small (56B) 182.0ms

4/4

Echo 1500B (DF) 115.1ms

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	2a00:8642:42::2	1.0ms	0%	AS203993	GNA-DC1-AS - S.J.M. Steffann, NL
2	*	-	0%*	-
3	2a00:1ca8:1::194	8.0ms	0%	AS50673	Serverius-as - Serverius Holding B.V., NL
4	2a03:3f40::10:41	7.0ms	0%	AS50673	Serverius-as - Serverius Holding B.V., NL
5	2001:978:2:40::3:1	4.6ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
6	be3458.ccr42.ams03.atlas.cogentco.com 2001:550:0:1000::9a36:27b9	7.7ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
7	be2950.ccr42.fra05.atlas.cogentco.com 2001:550:0:1000::9a36:482a	13.9ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
8	be5516.ccr21.muc03.atlas.cogentco.com 2001:550:0:1000::9a36:3e7a	21.7ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
9	be9456.ccr82.vie01.atlas.cogentco.com 2001:550:0:1000::9a36:3f8d	23.7ms	50%	AS174	COGENT-174 - Cogent Communications, LLC, US
10	be3935.agr61.vie01.atlas.cogentco.com 2001:550:0:1000::9a36:274e	22.3ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
11	br-v6-cogent.mmc.at 2001:978:2::3e:2	22.8ms	0%	AS174	COGENT-174 - Cogent Communications, LLC, US
12	rr2v852.vix2.mmc.at 2a00:1618:ffff:852::2	26.6ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
13	x2v861.vix2.mmc.at 2a00:1618:ffff:861::7	24.2ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
14	x1v816.hs1.mmc.at 2a00:1618:ffff:816::5	24.1ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
15	*	-	0%	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-

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

tracepath -6

 1?: [LOCALHOST]                        0.046ms pmtu 1500
 1:  2a00:8642:42::2                                       4.922ms 
 1:  2a00:8642:42::2                                       3.417ms 
 2:  gw.friends.steffann.nl                                9.135ms 
 3:  2a00:1ca8:1::194                                      7.475ms 
 4:  2a03:3f40::10:41                                     10.155ms 
 5:  2001:978:2:40::3:1                                    8.054ms 
 6:  be3457.ccr41.ams03.atlas.cogentco.com                16.085ms 
 7:  be2950.ccr42.fra05.atlas.cogentco.com                13.304ms 
 8:  be7944.ccr22.muc03.atlas.cogentco.com                18.646ms 
 9:  be9456.ccr82.vie01.atlas.cogentco.com                23.973ms 
10:  be3935.agr61.vie01.atlas.cogentco.com                24.484ms 
11:  br-v6-cogent.mmc.at                                  26.441ms 
12:  rr2v852.vix2.mmc.at                                  23.616ms asymm  8 
13:  x2v861.vix2.mmc.at                                   24.570ms asymm  9 
14:  x1v816.hs1.mmc.at                                    23.926ms asymm 10 
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  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

4/4

Echo small (56B) 19.7ms

3/4

Echo 1500B (DF) 20.0ms

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	*	-	-	-
2	*	-	-	-
3	2a12:d8c0:109f:106::a2	3.1ms	90%	AS204471	KARSOLINK - 2S Computers SRL, IT
4	2a02:2d8:1:b80d:232a	7.7ms	0%	-
5	RT.IRX.VIE.AT.retn.net 2a02:2d8::57f5:e0af	11.2ms	0%	AS9002	RETN-AS - RETN Limited, GB
6	2001:7f8:30:0:1:1:1:2577 @VIX / AAIX / SAIX / TIROL-IX / ERA-IX	15.9ms	0%	-	NA
7	rr1v850.vix3.mmc.at 2a00:1618:ffff:850::4	19.0ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
8	x2v861.vix2.mmc.at 2a00:1618:ffff:861::7	23.4ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
9	x1v816.hs1.mmc.at 2a00:1618:ffff:816::5	23.7ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
10	*	-	0%	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-

Rate-limited ICMPv6: hop 3 (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                                 8.712ms 
 4:  ae8-202.RT.CLR.MIL.IT.retn.net                        8.131ms asymm  5 
 5:  RT.IRX.VIE.AT.retn.net                               15.865ms 
 6:  2001:7f8:30:0:1:1:1:2577                             11.879ms 
 7:  rr1v850.vix3.mmc.at                                  23.539ms 
 8:  x1v861.vix3.mmc.at                                   23.928ms 
 9:  x1v816.hs1.mmc.at                                    23.962ms 
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
19:  no reply
20:  no reply
21:  no reply
22:  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) 8.6ms

4/4

Echo 1500B (DF) 8.6ms

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	0.5ms	0%*	AS8038	6CONNECT - 6connect, Inc., US
2	ccr-to-fw-ccr1-gw-lju.6connect.com 2607:fae0:a000:2::2	0.6ms	-	AS8038	6CONNECT - 6connect, Inc., US
3	2a03:a100:0:201:1::1	0.6ms	0%	AS56635	XENYA - XENYA inzeniring, proizvodnja in trgovina, d.o.o. Ljubljana, SI
4	*	-	50%	-
5	*	-	70%	-
6	2001:7f8:30:0:1:1:1:2577 @VIX / AAIX / SAIX / TIROL-IX / ERA-IX	8.5ms	0%	-	NA
7	rr1v850.vix3.mmc.at 2a00:1618:ffff:850::4	7.4ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
8	x2v861.vix2.mmc.at 2a00:1618:ffff:861::7	8.1ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
9	x1v816.hs1.mmc.at 2a00:1618:ffff:816::5	8.3ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
10	*	-	0%	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-

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

tracepath -6

 1?: [LOCALHOST]                        0.020ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.671ms 
 1:  fw1-lju.6connect.com                                  0.531ms 
 2:  no reply
 3:  2a03:a100:0:201:1::1                                  0.987ms 
 4:  2a03:a100:0:201:1::1                                  0.843ms pmtu 1500
 4:  e0-1.core1.lju1.he.net                                2.318ms 
 5:  100ge0-0-0-5.core1.vie1.he.net                        8.306ms 
 6:  2001:7f8:30:0:1:1:1:2577                              8.069ms asymm  5 
 7:  rr1v850.vix3.mmc.at                                   7.363ms asymm  5 
 8:  x2v861.vix2.mmc.at                                    8.522ms asymm  6 
 9:  x1v816.hs1.mmc.at                                     8.270ms asymm  7 
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
19:  no reply
20:  no reply
21:  no reply
22:  no reply
     Too many hops: pmtu 1500

From SLO host (T-2) openRFC 4890 ✓

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

4/4

Echo small (56B) 9.9ms

4/4

Echo 1500B (DF) 9.9ms

Type 1 dest-unreach

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	*	-	-	-
2	2a01:260:1::225	6.1ms	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	1.7ms	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	1.5ms	0%*	AS34779	T-2-AS - T-2, d.o.o., SI
5	2a01-260-1-1--2a.core6.t-2.net 2a01:260:1:1::2a	3.3ms	0%	AS34779	T-2-AS - T-2, d.o.o., SI
6	2001:7f8:30:0:1:1:1:2577 @VIX / AAIX / SAIX / TIROL-IX / ERA-IX	7.2ms	0%	-	NA
7	x1v861.vix3.mmc.at 2a00:1618:ffff:861::6	8.8ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
8	x1v816.hs1.mmc.at 2a00:1618:ffff:816::5	8.2ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
9	x1v816.hs1.mmc.at 2a00:1618:ffff:816::5	8.2ms	0%	AS12577	MMC-AT-AS - MMC GmbH, AT
10	*	-	-	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.027ms pmtu 1500
 1:  no reply
 2:  2a01:260:1::225                                       2.727ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        2.499ms 
 4:  2a01-260-1-1--c.core6.t-2.net                         4.442ms 
 5:  2001:7f8:30:0:1:1:1:2577                              7.514ms 
 6:  2001:7f8:30:0:1:1:1:2577                              9.214ms asymm  5 
 7:  x1v861.vix3.mmc.at                                    9.567ms 
 8:  x1v816.hs1.mmc.at                                     9.497ms 
 9:  x1v816.hs1.mmc.at                                     9.236ms asymm  8 
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
19:  no reply
20:  no reply
21:  no reply
22:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500