AS208753 NETSIX Marco d'Angelo

AS overview

Test target: 2a09:b280:ff60::1 · static prefix probe · address space: unknown · prefixes announced: 17

prefix(es): 2a0f:1cc5:61::/48, 2a0c:b642:a07::/48, 2a05:b0c6:200f::/48, 2a0c:b642:a04::/48, 2a0c:b642:a09::/48, 2a0e:b107:384::/48, 2a0f:1cc5:62::/48, 2a0c:b642:a08::/48 (+9 more)

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
`2a09:b280:ff60::1`	prb	✓	✗	open	open	✓	✓	✗	open	open	✓	✓	✗	open	open	✓	✓	✗	open	open	✓	✓	✗	open	open	✓	✓	✗	open	open	✓	✓	✗	open	open	✓

RPKI & ASPA

17 of 17 prefix(es) covered by a valid ROA.

Prefix	RPKI state	Reason	Covering VRP(s)
`2a0f:1cc5:61::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS208753 /44 maxLen 48 (ripe)
`2a0c:b642:a07::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a05:b0c6:200f::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS208753 /48 maxLen 48 (ripe)
`2a0c:b642:a04::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a0c:b642:a09::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a0e:b107:384::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS208753 /48 maxLen 48 (ripe)
`2a0f:1cc5:62::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS208753 /44 maxLen 48 (ripe)
`2a0c:b642:a08::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a09:b280:ff60::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS208753 /48 maxLen 48 (ripe)
`2406:840:eeb1::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS208753 /44 maxLen 48 (apnic)
`2a0c:b642:a02::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a05:b0c6:200a::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS208753 /48 maxLen 48 (ripe)
`2a0c:b642:a01::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a0c:b642:a05::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a0c:b642:a03::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a0c:b642:a06::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS206499 /44 maxLen 48 (ripe); AS208753 /44 maxLen 48 (ripe); AS205591 /36 maxLen 48 (ripe); AS206499 /36 maxLen 48 (ripe)
`2a10:ba87:feef::/48`	✓ valid	matched VRP (correct origin, length within maxLength)	AS208753 /48 maxLen 48 (ripe)

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

At least one router inside AS208753's announced prefix replied during the random-target probe. Hop(s): 2a0c:b642:a07:faf0::1. 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 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
DE host (Berlin): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
DE host (Düsseldorf): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
NL host (go6lab): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
ITA host (Karsolink): inconclusive: no Echo Reply to 1300-byte probe. (ICMPv6 Echo + forged PTB)
SLO host (6connect): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
SLO host (T-2): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (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.

Failure detail - what to grep in your logs

vantage	our source	your target	method	result	tested (UTC)
belgrade	`2a09:ab81::91`	`2a09:b280:ff60::1`	`icmp6-echo`	not_honored	2026-09-23T12:06:14Z
berlin	`2a06:d1c1:10b::cccc`	`2a09:b280:ff60::1`	`icmp6-echo`	not_honored	2026-09-23T12:06:13Z
duseldorf	`2a06:d1c1:10d::aaaa`	`2a09:b280:ff60::1`	`icmp6-echo`	not_honored	2026-09-23T12:06:11Z
go6lab	`2a00:8642:42::75`	`2a09:b280:ff60::1`	`icmp6-echo`	not_honored	2026-09-23T12:07:35Z
karsolink	`2a12:d8c0:105a:9001::a154`	`2a09:b280:ff60::1`	`icmp6-echo`	no_echo	2026-09-23T12:06:08Z
odin	`2607:fae0:a000::42`	`2a09:b280:ff60::1`	`icmp6-echo`	not_honored	2026-09-23T12:06:11Z
t2	`2a01:261:313:b814:2a0:98ff:fe5b:13e4`	`2a09:b280:ff60::1`	`icmp6-echo`	not_honored	2026-09-23T12:06:14Z

Attempt log (belgrade):

icmp6-echo → not_honored (reply shrank 1260→1260 B)
dns-tcp → inconclusive (reply 733 B before PTB): max DNS-over-TCP segment 733B; not big enough to test PMTU shrink
tls → inconclusive (reply 7 B before PTB): largest TLS segment 7B too small to detect shrink
http → inconclusive (reply 163 B before PTB): natural max segment 163B already <= 1220B; nothing to shrink

Attempt log (berlin):

icmp6-echo → not_honored (reply shrank 1260→1260 B)
dns-tcp → inconclusive (reply 430 B before PTB): max DNS-over-TCP segment 430B; not big enough to test PMTU shrink
tls → inconclusive: TLS exchange produced no observable segment data
http → inconclusive (reply 163 B before PTB): natural max segment 163B already <= 1220B; nothing to shrink

Attempt log (duseldorf):

icmp6-echo → not_honored (reply shrank 1260→1260 B)
dns-tcp → inconclusive (reply 430 B before PTB): max DNS-over-TCP segment 430B; not big enough to test PMTU shrink
tls → inconclusive: TLS exchange produced no observable segment data
http → inconclusive (reply 163 B before PTB): natural max segment 163B already <= 1220B; nothing to shrink

Attempt log (go6lab):

icmp6-echo → not_honored (reply shrank 1260→1260 B)
dns-tcp → inconclusive (reply 514 B before PTB): max DNS-over-TCP segment 514B; not big enough to test PMTU shrink
tls → inconclusive: TLS exchange produced no observable segment data
http → inconclusive (reply 163 B before PTB): natural max segment 163B already <= 1220B; nothing to shrink

Attempt log (karsolink):

icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
dns-tcp → inconclusive (reply 705 B before PTB): max DNS-over-TCP segment 705B; not big enough to test PMTU shrink
tls → inconclusive (reply 7 B before PTB): largest TLS segment 7B too small to detect shrink
http → inconclusive (reply 163 B before PTB): natural max segment 163B already <= 1220B; nothing to shrink

Attempt log (odin):

icmp6-echo → not_honored (reply shrank 1260→1260 B)
dns-tcp → inconclusive (reply 430 B before PTB): max DNS-over-TCP segment 430B; not big enough to test PMTU shrink
tls → inconclusive (reply 7 B before PTB): largest TLS segment 7B too small to detect shrink
http → inconclusive (reply 163 B before PTB): natural max segment 163B already <= 1220B; nothing to shrink

Attempt log (t2):

icmp6-echo → not_honored (reply shrank 1260→1260 B)
dns-tcp → inconclusive (reply 733 B before PTB): max DNS-over-TCP segment 733B; not big enough to test PMTU shrink
tls → inconclusive (reply 7 B before PTB): largest TLS segment 7B too small to detect shrink
http → inconclusive (reply 163 B before PTB): natural max segment 163B already <= 1220B; nothing to shrink

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 1260 B; after, it was 1260 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 (2026-09-23T12:06:14Z) 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.

Where the path divergence is

Per-vantage probe + verdict (headline):

belgrade: probe icmp6-echo → verdict not_honored
berlin: probe icmp6-echo → verdict not_honored
duseldorf: probe icmp6-echo → verdict not_honored
go6lab: probe icmp6-echo → verdict not_honored
karsolink: probe icmp6-echo → verdict no_echo
odin: probe icmp6-echo → verdict not_honored
t2: probe icmp6-echo → verdict not_honored

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

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

✓ 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): AS208753, AS6517, AS6939.

From belgrade (echo_only/Type-2=not_honored) the path enters an opaque hop at hop 10; from berlin (echo_only/Type-2=not_honored) the same hop is in AS208753. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (echo_only/Type-2=not_honored) the path enters an opaque hop at hop 10; from duseldorf (echo_only/Type-2=not_honored) the same hop is in AS208753. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (echo_only/Type-2=not_honored) the path enters AS208753 at hop 5; from go6lab (echo_only/Type-2=not_honored) the same hop is in AS31500. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (echo_only/Type-2=not_honored) the path enters AS208753 at hop 5; from karsolink (echo_only/Type-2=no_echo) the same hop is in AS6517. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (echo_only/Type-2=not_honored) the path enters an opaque hop at hop 11; from odin (echo_only/Type-2=not_honored) the same hop is in AS208753. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From belgrade (echo_only/Type-2=not_honored) the path enters an opaque hop at hop 10; from t2 (echo_only/Type-2=not_honored) the same hop is in AS208753. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From berlin (echo_only/Type-2=not_honored) the path enters AS1299 at hop 7; from go6lab (echo_only/Type-2=not_honored) the same hop is in AS6939. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From berlin (echo_only/Type-2=not_honored) the path enters AS1299 at hop 7; from karsolink (echo_only/Type-2=no_echo) the same hop is in AS208753. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From berlin (echo_only/Type-2=not_honored) the path enters an opaque hop at hop 11; from odin (echo_only/Type-2=not_honored) the same hop is in AS208753. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From duseldorf (echo_only/Type-2=not_honored) the path enters AS208753 at hop 10; from go6lab (echo_only/Type-2=not_honored) the same hop is in AS6517. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From duseldorf (echo_only/Type-2=not_honored) the path enters AS208753 at hop 10; from karsolink (echo_only/Type-2=no_echo) the same hop is in an opaque hop. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From duseldorf (echo_only/Type-2=not_honored) the path enters an opaque hop at hop 11; from odin (echo_only/Type-2=not_honored) the same hop is in AS208753. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From go6lab (echo_only/Type-2=not_honored) the path enters AS50673 at hop 4; from karsolink (echo_only/Type-2=no_echo) the same hop is in AS6517. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From go6lab (echo_only/Type-2=not_honored) the path enters AS50673 at hop 3; from odin (echo_only/Type-2=not_honored) the same hop is in AS56635. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From go6lab (echo_only/Type-2=not_honored) the path enters AS6939 at hop 7; from t2 (echo_only/Type-2=not_honored) the same hop is in an opaque hop. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From karsolink (echo_only/Type-2=no_echo) the path enters AS6517 at hop 4; from odin (echo_only/Type-2=not_honored) the same hop is in AS6939. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From karsolink (echo_only/Type-2=no_echo) the path enters an opaque hop at hop 10; from t2 (echo_only/Type-2=not_honored) the same hop is in AS208753. Last common AS: AS208753. The disagreement is most likely rooted in one of those two transit ASes.
From odin (echo_only/Type-2=not_honored) the path enters an opaque hop at hop 6; from t2 (echo_only/Type-2=not_honored) the same hop is in AS6939. Last common AS: AS208753. 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) echo onlyRFC 4890 ✗

filter likely at: destination AS208753 (NETSIX) · min PMTU on path: 1476

4/4

Echo small (56B) 97.0ms

0/4

Echo 1500B (DF) -

yes

Type 1 dest-unreach

443,80

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	sox-pn.sox.rs 2001:7f8:1e:8::3a	0.4ms	0%	AS13004	SOX - Serbian Open Exchange DOO, RS
3	2001:7f8:1e:8::3d	0.6ms	0%	AS13004	SOX - Serbian Open Exchange DOO, RS
4	2001:67c:128c::699	16.9ms	0%	-	NA
5	habanero.local 2a09:b280:ff60::1	109.6ms	0%	AS208753	NETSIX - Marco d_Angelo, IT

tracepath -6

 1?: [LOCALHOST]                        0.014ms pmtu 1500
 1:  _gateway                                              0.440ms 
 1:  _gateway                                              0.749ms 
 2:  sox-pn.sox.rs                                         0.668ms 
 3:  2001:7f8:1e:8::3d                                     0.710ms asymm  2 
 4:  2001:67c:128c::699                                   18.219ms 
 5:  revolution-ic-386537.ip.twelve99-cust.net            46.777ms pmtu 1476
 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 1476

From DE host (Berlin) echo onlyRFC 4890 ✗

filter likely at: destination AS208753 (NETSIX) · min PMTU on path: 1476

4/4

Echo small (56B) 53.7ms

0/4

Echo 1500B (DF) -

yes

Type 1 dest-unreach

443,80

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	0.8ms	0%*	AS59645	WYBT-NET - Tobias Fiebig, DE
3	ae0-150.cr10.fra01.lwlcom.net 2a00:c380:b200:230::174	10.2ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
4	ae0-100.cr10.fra02.lwlcom.net 2a00:c380:b200:230::215	10.3ms	0%	AS50629	LWLCOM - LWLcom GmbH, DE
5	ffm-b29-link.ip.twelve99.net 2001:2035:0:2741::1	12.7ms	0%	AS1299	TWELVE99 - Arelion Sweden AB, SE
6	2001:2034:a:3bb	27.6ms	0%	-
7	revolution-ic-386537.ip.twelve99-cust.net 2001:2035:0:257c::2	19.1ms	0%	AS1299	TWELVE99 - Arelion Sweden AB, SE
8	*	-	-	-
9	*	-	-	-
10	habanero.local 2a09:b280:ff60::1	52.8ms	0%	AS208753	NETSIX - Marco d_Angelo, IT

tracepath -6

 1?: [LOCALHOST]                        0.026ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.579ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.567ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.941ms 
 3:  ae0-150.cr10.fra01.lwlcom.net                        10.388ms asymm  7 
 4:  ae0-100.cr10.fra02.lwlcom.net                        10.568ms asymm  8 
 5:  ffm-b29-link.ip.twelve99.net                         12.413ms asymm  9 
 6:  ffm-bb1-link.ip.twelve99.net                         27.859ms asymm  7 
 7:  revolution-ic-386537.ip.twelve99-cust.net            19.460ms asymm  8 
 8:  revolution-ic-386537.ip.twelve99-cust.net            19.533ms pmtu 1476
 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 1476

From DE host (Düsseldorf) echo onlyRFC 4890 ✗

filter likely at: destination AS208753 (NETSIX) · min PMTU on path: 1476

4/4

Echo small (56B) 71.0ms

0/4

Echo 1500B (DF) -

yes

Type 1 dest-unreach

443,80

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	lag11.core3-dus1.bb.wiit.network 2001:4ba0:ffe9:115::3	0.2ms	0%	AS24961	MYLOC-AS - WIIT AG, DE
5	ddf-b4-link.ip.twelve99.net 2001:2035:0:9fb::1	0.8ms	0%	AS1299	TWELVE99 - Arelion Sweden AB, SE
6	ddf-b5-link.ip.twelve99.net 2001:2034:a:336::1	2.4ms	0%	AS1299	TWELVE99 - Arelion Sweden AB, SE
7	2001:2034:a:15a	21.5ms	0%	-
8	*	-	-	-
9	*	-	-	-
10	habanero.local 2a09:b280:ff60::1	47.6ms	0%	AS208753	NETSIX - Marco d_Angelo, IT

tracepath -6

 1?: [LOCALHOST]                        0.013ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.270ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.237ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            1.093ms 
 3:  no reply
 4:  lag30.core3-dus1.bb.wiit.network                      0.429ms 
 5:  ddf-b4-link.ip.twelve99.net                           1.066ms 
 6:  ddf-b5-link.ip.twelve99.net                           3.029ms 
 7:  ffm-bb1-link.ip.twelve99.net                         21.825ms asymm  6 
 8:  revolution-ic-386537.ip.twelve99-cust.net            13.297ms pmtu 1476
 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 1476

From NL host (go6lab) echo onlyRFC 4890 ✗

filter likely at: destination AS208753 (NETSIX) · min PMTU on path: 1420

4/4

Echo small (56B) 73.1ms

0/4

Echo 1500B (DF) -

yes

Type 1 dest-unreach

443,80

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	2a00:8642:42::2	2.9ms	0%	AS203993	GNA-DC1-AS - S.J.M. Steffann, NL
2	*	-	0%*	-
3	2a00:1ca8:1::194	3.4ms	0%	AS50673	Serverius-as - Serverius Holding B.V., NL
4	2a03:3f40::10:41	4.5ms	0%	AS50673	Serverius-as - Serverius Holding B.V., NL
5	2001:b28:3ff::1b1b:0:1	35.2ms	0%	AS31500	GNM-AS - Global Network Management Inc, AG
6	be9.core4.fra1.he.net 2001:470:e:e9::1	37.0ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
7	be10.core1.zrh2.he.net 2001:470:e:153::2	36.8ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
8	be1.core1.mil2.he.net 2001:470:e:dd::1	43.4ms	0%	AS6939	HURRICANE - Hurricane Electric LLC, US
9	*	-	-	-
10	lakenetworks.minap.it 2001:7f8:c5::a500:6517:1	36.8ms	0%	AS6517	Lakenetworks
11	rs5.v6-IT-Milano.6project.org 2a14:7584:448d::2	39.4ms	0%	AS6517	LAKENETWORKS-AS - LAKENETWORKS, US
12	fd00:206:25::2	71.3ms	0%	-	NA
13	habanero.local 2a09:b280:ff60::1	72.2ms	10%	AS208753	NETSIX - Marco d_Angelo, IT

Rate-limited ICMPv6: hop 13 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.034ms pmtu 1420
 1:  2a00:8642:42::2                                       2.075ms 
 1:  2a00:8642:42::2                                       1.618ms 
 2:  gw.friends.steffann.nl                                4.447ms 
 3:  2a00:1ca8:1::194                                      5.386ms 
 4:  2a03:3f40::10:41                                     17.520ms 
 5:  2001:b28:3ff::1b1b:0:1                               35.240ms 
 6:  be6.core4.fra1.he.net                                34.430ms asymm  4 
 7:  be10.core1.zrh2.he.net                               39.081ms asymm  5 
 8:  be1.core1.mil2.he.net                                44.545ms asymm  6 
 9:  no reply
10:  lakenetworks.minap.it                                39.143ms asymm  8 
11:  rs5.v6-IT-Milano.6project.org                        41.092ms asymm  9 
12:  fd00:206:25::2                                       71.720ms asymm 10 
13:  habanero.local                                       73.506ms reached
     Resume: pmtu 1420 hops 13 back 11

From ITA host (Karsolink) echo only

filter likely at: destination AS208753 (NETSIX) · min PMTU on path: 1420

4/4

Echo small (56B) 87.3ms

0/4

Echo 1500B (DF) -

yes

Type 1 dest-unreach

443,80

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	0.5ms	0%*	AS204471	KARSOLINK - 2S Computers SRL, IT
2	*	-	0%*	-
3	*	-	20%	-
4	lakenetworks.minap.it 2001:7f8:c5::a500:6517:1	9.8ms	0%	AS6517	Lakenetworks
5	rs5.v6-IT-Milano.6project.org 2a14:7584:448d::2	10.0ms	0%	AS6517	LAKENETWORKS-AS - LAKENETWORKS, US
6	*	-	-	-
7	habanero.local 2a09:b280:ff60::1	43.3ms	0%	AS208753	NETSIX - Marco d_Angelo, IT

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

tracepath -6

 1?: [LOCALHOST]                        0.031ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.628ms 
 1:  karsolink-01.net.karsolink.com                        0.600ms 
 2:  2a12:d8c0:109f:121::a1                                0.633ms 
 3:  2a12:d8c0:101f:6::1                                  10.159ms 
 4:  lakenetworks.minap.it                                10.343ms 
 5:  rs5.v6-IT-Milano.6project.org                        10.851ms 
 6:  rs5.v6-IT-Milano.6project.org                        10.528ms pmtu 1420
 6:  no reply
 7:  habanero.local                                       44.335ms reached
     Resume: pmtu 1420 hops 7 back 7

From SLO host (6connect) echo onlyRFC 4890 ✗

filter likely at: destination AS208753 (NETSIX) · min PMTU on path: 1420

4/4

Echo small (56B) 63.6ms

0/4

Echo 1500B (DF) -

yes

Type 1 dest-unreach

443,80

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	*	-	-	-
3	2a03:a100:0:201:1::1	0.9ms	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	1.9ms	80%	AS6939	HURRICANE - Hurricane Electric LLC, US
5	*	-	-	-
6	*	-	50%	-
7	*	-	-	-
8	lakenetworks.minap.it 2001:7f8:c5::a500:6517:1	12.2ms	0%	AS6517	Lakenetworks
9	rs5.v6-IT-Milano.6project.org 2a14:7584:448d::2	12.2ms	0%	AS6517	LAKENETWORKS-AS - LAKENETWORKS, US
10	fd00:206:25::2	45.0ms	0%	-	NA
11	habanero.local 2a09:b280:ff60::1	45.7ms	0%	AS208753	NETSIX - Marco d_Angelo, IT

Rate-limited ICMPv6: hop 4, hop 6 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.024ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.655ms 
 1:  fw1-lju.6connect.com                                  0.479ms 
 2:  ccr-to-fw-ccr1-gw-lju.6connect.com                    1.242ms 
 3:  2a03:a100:0:201:1::1                                  1.127ms 
 4:  2a03:a100:0:201:1::1                                  1.308ms pmtu 1500
 4:  e0-1.core1.lju1.he.net                                2.300ms 
 5:  no reply
 6:  port-channel1.core1.zag2.he.net                       4.461ms 
 7:  no reply
 8:  lakenetworks.minap.it                                12.127ms 
 9:  rs5.v6-IT-Milano.6project.org                        12.374ms 
10:  rs5.v6-IT-Milano.6project.org                        12.416ms pmtu 1420
10:  fd00:206:25::2                                       45.178ms 
11:  habanero.local                                       45.675ms reached
     Resume: pmtu 1420 hops 11 back 11

From SLO host (T-2) echo onlyRFC 4890 ✗

filter likely at: destination AS208753 (NETSIX) · min PMTU on path: 1420

4/4

Echo small (56B) 73.6ms

0/4

Echo 1500B (DF) -

yes

Type 1 dest-unreach

443,80

TCP responds on

Path (traceroute + mtr + PTR)

#	IP / PTR	RTT	mtr loss	AS	AS holder
1	*	-	0%*	-
2	2a01:260:1::225	4.3ms	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	1.8ms	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	2.5ms	-	AS34779	T-2-AS - T-2, d.o.o., SI
5	*	-	0%	-
6	port-channel1.core1.zag2.he.net 2001:470:0:2ea::2	10.6ms	-	AS6939	HURRICANE - Hurricane Electric LLC, US
7	*	-	0%	-
8	rs5.v6-IT-Milano.6project.org 2a14:7584:448d::2	17.2ms	0%	AS6517	LAKENETWORKS-AS - LAKENETWORKS, US
9	rs5.v6-IT-Milano.6project.org 2a14:7584:448d::2	16.6ms	-	AS6517	LAKENETWORKS-AS - LAKENETWORKS, US
10	habanero.local 2a09:b280:ff60::1	50.3ms	0%	AS208753	NETSIX - Marco d_Angelo, IT

tracepath -6

 1?: [LOCALHOST]                        0.028ms pmtu 1500
 1:  no reply
 2:  2a01:260:1::225                                       5.263ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        2.945ms 
 4:  2a01-260-1-1--38.core6.t-2.net                        3.134ms asymm  3 
 5:  port-channel1.core1.zag2.he.net                      10.624ms asymm  7 
 6:  port-channel1.core1.zag2.he.net                      10.275ms asymm  7 
 7:  lakenetworks.minap.it                                16.375ms 
 8:  lakenetworks.minap.it                                16.371ms asymm  7 
 9:  rs5.v6-IT-Milano.6project.org                        17.524ms pmtu 1420
 9:  rs5.v6-IT-Milano.6project.org                        17.466ms asymm  8 
10:  ???                                                  50.928ms reached
     Resume: pmtu 1420 hops 10 back 10