AS33986 - ASN-REDDER Redder Telco s.r.lPARPKI ✓ 1/1ASPA -

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IPv6 prefix announced, but nothing inside is responding yet. AS33986 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: 2a00:5b00::1 · (no live host found) · address space: PA · prefixes announced: 1

prefix(es): 2a00:5b00::/29

MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO peering

MIX-IT / NAMEX / MINAP / TOP-IX / VSIX / EQUINIX-MILAN / BGPX-ROME / NAMEX-BARI / PCIX / DECIX-PALERMO member - Open peering, peering member, since 2014-06-22. IPv6 LAN: 2001:7f8:b:100:1d1:a5d3:3986:165. Locations: -.

RPKI & ASPA

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

PrefixRPKI stateReasonCovering VRP(s)
2a00:5b00::/29✓ validmatched VRP (correct origin, length within maxLength)AS33986 /29 maxLen 29 (ripe)

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

We probed 15 arbitrary IPv6 address(es) inside AS33986's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a00:ee0:1:10::2 at hop 4 - that router answers ICMPv6 Echo. This is not in AS33986'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 2026-05-25T12:29:23Z

Failure detail — what to grep in your logs
vantageour sourceyour targetmethodresulttested (UTC)
go6lab2a00:8642:42::752a00:5b00::1icmp6-echono_echo2026-05-25T12:29:23Z
karsolink2a12:d8c0:105a:9001::a1542a00:5b00::1icmp6-echono_echo2026-05-25T12:32:50Z
odin2607:fae0:a000::422a00:5b00::1icmp6-echono_echo2026-05-25T12:29:14Z

Attempt log (go6lab):

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

Attempt log (karsolink):

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

Attempt log (odin):

  1. icmp6-echo → no_echo: no Echo Reply to 1300-byte probe
  2. dns-tcp → no_tcp: connect failed: timed out
  3. tls → no_tcp: TLS connect failed
  4. 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 AS203993 (STEFFANN-DC-AS) · min PMTU on path: 1500

0/4
Echo small (56B) -
0/4
Echo 1500B (DF) -
no
Type 1 dest-unreach
-
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
12a00:8642:42::31.7ms0%AS203993STEFFANN-DC-AS - S.J.M. Steffann, NL
2gw.friends.steffann.nl
2a00:8642:1000:f000::1		2.8ms0%*AS203993STEFFANN-DC-AS - S.J.M. Steffann, NL
3ccr2-ccr1.dc1.nogalliance.org
2a00:8642:dc1:2::b		1.8ms0%AS203993STEFFANN-DC-AS - S.J.M. Steffann, NL
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tracepath -6

 1?: [LOCALHOST]                        0.033ms pmtu 1500
 1:  2a00:8642:42::3                                       1.514ms 
 1:  2a00:8642:42::3                                       1.664ms 
 2:  gw.friends.steffann.nl                                2.989ms 
 3:  ccr2-ccr1.dc1.nogalliance.org                         3.072ms asymm  2 
 4:  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 AS204471 (KARSOLINK) · min PMTU on path: 1500

0/4
Echo small (56B) -
0/4
Echo 1500B (DF) -
no
Type 1 dest-unreach
-
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1*-0%*-
22a12:d8c0:109f:121::a10.4ms0%*AS204471KARSOLINK - 2S Computers SRL, IT
3*-30%-
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Rate-limited ICMPv6: hop 3 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.030ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.489ms 
 1:  karsolink-01.net.karsolink.com                        0.787ms 
 2:  2a12:d8c0:109f:121::a1                                0.860ms 
 3:  2a12:d8c0:101f:103::1                                 8.979ms 
 4:  no reply
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     Too many hops: pmtu 1500
     Resume: pmtu 1500

From SLO host (6connect)   transit only unreachable

filter likely at: past AS5603 (SIOL-NET) · min PMTU on path: 1500

0/4
Echo small (56B) -
0/4
Echo 1500B (DF) -
no
Type 1 dest-unreach
-
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1fw1-lju.6connect.com
2607:fae0:a000::2		0.2ms0%*AS80386CONNECT - 6connect, Inc., US
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32a00:ee1:800:9::12.1ms10%AS5603SIOL-NET - Telekom Slovenije, d.d., SI
42a00:ee0:1:15::20.8ms0%AS5603SIOL-NET - Telekom Slovenije, d.d., SI
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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:  fw1-lju.6connect.com                                  0.445ms 
 1:  fw1-lju.6connect.com                                  0.558ms 
 2:  no reply
 3:  2a00:ee1:800:9::1                                     2.237ms 
 4:  2a00:ee0:1:10::2                                      1.037ms asymm  3 
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     Too many hops: pmtu 1500
     Resume: pmtu 1500