AS33964 SOGEI-ASN Sogei Societa' Generale d' Informatica S.p.A.

IPv6 prefix announced, but nothing inside is responding yet. AS33964 announces 1 IPv6 prefix(es) to the global routing table - that’s the part that BGP and our route-server scrape confirm. But our active discovery (curated hostnames, holder-derived domains, authoritative DNS NS/SOA/MX, certificate-transparency hostnames, RIPE Atlas, RDAP, IPv6 Hitlist) found no ICMPv6-responsive host inside the prefix on either vantage, and a yarrp pass against random addresses inside the prefix produced zero in-prefix hops (no router on the path through the AS replied with Time-Exceeded for any random target). That combination usually means the announcement is configured but the addresses inside aren’t in active use yet. The BGP route is there; the operational deployment is still ahead.

AS overview

Test target: 2a00:e540::1 · (no live host found) · address space: PA · prefixes announced: 1

prefix(es): 2a00:e540::/32

RPKI & ASPA

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

Prefix	RPKI state	Reason	Covering VRP(s)
`2a00:e540::/32`	- not-found	no covering VRP

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

We probed 15 arbitrary IPv6 address(es) inside AS33964's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2001:b00:1:1:2::d9 at hop 13 - that router does not answer ICMPv6 Echo. This is not in AS33964'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 active test inconclusive: no Echo Reply to 1300-byte probe.
method: ICMPv6 Echo + forged PTB, tested 2026-05-25T12:29:58Z

Failure detail — what to grep in your logs

vantage	our source	your target	method	result	tested (UTC)
go6lab	`2a00:8642:42::75`	`2a00:e540::1`	`icmp6-echo`	no_echo	2026-05-25T12:29:58Z
karsolink	`2a12:d8c0:105a:9001::a154`	`2a00:e540::1`	`icmp6-echo`	no_echo	2026-05-25T12:34:30Z
odin	`2607:fae0:a000::42`	`2a00:e540::1`	`icmp6-echo`	no_echo	2026-05-25T12:29:46Z

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

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 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 one of our two source IPs, the drop is path-asymmetric — one transit on the asymmetric route is filtering, the other is not.

From NL host (go6lab) transit only unreachable

filter likely at: past AS12874 (FASTWEB) · min PMTU on path: 1500

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::3	2.4ms	0%	AS203993	STEFFANN-DC-AS - S.J.M. Steffann, NL
2	gw.friends.steffann.nl 2a00:8642:1000:f000::1	3.2ms	0%*	AS203993	STEFFANN-DC-AS - S.J.M. Steffann, NL
3	2a00:1ca8:1::194	3.1ms	0%	AS50673	Serverius-as - Serverius Holding B.V., NL
4	2a03:3f40::10:33	5.2ms	0%	AS50673	Serverius-as - Serverius Holding B.V., NL
5	2001:7f8:1::a501:2874:1	22.9ms	0%	-	NA
6	2001:b00:1:1:3::133	21.7ms	0%	AS12874	FASTWEB - Fastweb SpA, IT
7	2001:b00:1:1:2::ab	35.0ms	0%	AS12874	FASTWEB - Fastweb SpA, IT
8	2001:b00:1:1:2::db	33.5ms	0%	AS12874	FASTWEB - Fastweb SpA, IT
9	*	-	-	-
10	*	-	-	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-
23	*	-	-	-
24	*	-	-	-

tracepath -6

 1?: [LOCALHOST]                        0.051ms pmtu 1500
 1:  2a00:8642:42::3                                       1.527ms 
 1:  2a00:8642:42::3                                       1.406ms 
 2:  gw.friends.steffann.nl                                1.986ms 
 3:  2a00:1ca8:1::194                                      4.714ms 
 4:  2a03:3f40::10:33                                      5.829ms 
 5:  2001:7f8:1::a501:2874:1                              21.866ms 
 6:  2001:b00:1:1:3::133                                  20.940ms 
 7:  2001:b00:1:1:3::d7                                   32.483ms 
 8:  2001:b00:1:1:2::d9                                   30.209ms 
 9:  no reply
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     Too many hops: pmtu 1500
     Resume: pmtu 1500

From ITA host (Karsolink) transit only unreachable

filter likely at: past AS12874 (FASTWEB) · min PMTU on path: 1500

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	*	-	0%*	-
3	2a12:d8c0:101f:6::1	10.0ms	0%	AS204471	KARSOLINK - 2S Computers SRL, IT
4	*	-	50%	-
5	2001:b00:1:1:1::1af	9.7ms	0%	AS12874	FASTWEB - Fastweb SpA, IT
6	2001:b00:1:1:3::d7	21.3ms	0%	AS12874	FASTWEB - Fastweb SpA, IT
7	2001:b00:1:1:2::db	21.7ms	0%	AS12874	FASTWEB - Fastweb SpA, IT
8	*	-	-	-
9	*	-	-	-
10	*	-	-	-
11	*	-	-	-
12	*	-	-	-
13	*	-	-	-
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-
23	*	-	-	-
24	*	-	-	-

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

tracepath -6

 1?: [LOCALHOST]                        0.032ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.572ms 
 1:  karsolink-01.net.karsolink.com                        0.865ms 
 2:  2a12:d8c0:109f:121::a1                                0.807ms 
 3:  2a12:d8c0:101f:6::1                                  10.434ms 
 4:  fastweb.minap.it                                     11.405ms 
 5:  2001:b00:1:1:1::1af                                  10.143ms 
 6:  2001:b00:1:1:3::d7                                   18.259ms 
 7:  2001:b00:1:1:2::d9                                   22.252ms 
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     Too many hops: pmtu 1500
     Resume: pmtu 1500

From SLO host (6connect) transit only unreachable

filter likely at: past AS12874 (FASTWEB) · min PMTU on path: 1500

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	0.5ms	0%*	AS8038	6CONNECT - 6connect, Inc., US
2	*	-	-	-
3	*	-	70%	-
4	2a00:ee0:1:10::2	0.9ms	0%	AS5603	SIOL-NET - Telekom Slovenije, d.d., SI
5	2001:1900:5:2:2:0:11c:d49	6.2ms	0%	AS3356	LEVEL3 - Level 3 Parent, LLC, US
6	*	-	0%	-
7	i79zhh-005-ae33.bb.ip-plus.net 2001:4d98:a000::ca	14.1ms	0%	-	NA
8	i71lzw-015-loo179.bb.ip-plus.net 2001:918:100:24::1	16.1ms	0%	AS3303	SWISSCOM - Swisscom (Schweiz) AG, CH
9	i63lgv-015-loo179.bb.ip-plus.net 2001:918:100:11::1	14.5ms	0%	AS3303	SWISSCOM - Swisscom (Schweiz) AG, CH
10	as3303-as12874-lug-001-ser0.ce.ip-plus.net 2001:4d98:a000::143	17.9ms	80%	-	NA
11	2001:b00:1:1:3::12f	16.4ms	0%	AS12874	FASTWEB - Fastweb SpA, IT
12	2001:b00:1:1:2::ab	29.2ms	0%	AS12874	FASTWEB - Fastweb SpA, IT
13	2001:b00:1:1:2::db	33.4ms	10%	AS12874	FASTWEB - Fastweb SpA, IT
14	*	-	-	-
15	*	-	-	-
16	*	-	-	-
17	*	-	-	-
18	*	-	-	-
19	*	-	-	-
20	*	-	-	-
21	*	-	-	-
22	*	-	-	-
23	*	-	-	-
24	*	-	-	-

Rate-limited ICMPv6: hop 3, hop 10, hop 13 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.037ms pmtu 1500
 1:  fw1-lju.6connect.com                                  0.621ms 
 1:  fw1-lju.6connect.com                                  0.506ms 
 2:  no reply
 3:  no reply
 4:  2a00:ee0:1:10::2                                      1.169ms asymm  3 
 5:  2001:1900:5:2:2:0:11c:d49                             6.997ms asymm  7 
 6:  no reply
 7:  i79zhh-005-ae33.bb.ip-plus.net                       28.126ms 
 8:  i71lzw-015-loo179.bb.ip-plus.net                     14.491ms asymm  7 
 9:  i63lgv-015-loo179.bb.ip-plus.net                     14.754ms asymm  6 
10:  as3303-as12874-lug-001-ser0.ce.ip-plus.net           24.958ms asymm  7 
11:  2001:b00:1:1:3::12f                                  16.374ms asymm  9 
12:  2001:b00:1:1:2::ab                                   24.611ms asymm 10 
13:  2001:b00:1:1:2::db                                   32.012ms asymm 11 
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     Too many hops: pmtu 1500
     Resume: pmtu 1500