AS20836 - CDLAN-AS CDLAN SpARFC 4890 ✓RPKI ⚠ 3/5ASPA -

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AS overview

Test target: 2a07:2840::3 · ns1.x4w.net · address space: unknown · prefixes announced: 5

prefix(es): 2001:b60::/32, 2a0a:ec00::/32, 2a07:2847::/32, 2001:b61::/32, 2a07:2840::/32

Targets & per-vantage-point probe results (1 target(s) across 3 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 / hostnameSourceNL host (go6lab)ITA host (Karsolink)SLO host (6connect)
ping1500B:80:443reachedping1500B:80:443reachedping1500B:80:443reached
2a07:2840::3
ns1.x4w.net
NS?open-?open-?open-

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 2013-05-14. IPv6 LAN: 2001:7f8:b:100:1d1:a5d2:836:16. Locations: -.

RPKI & ASPA

3 of 5 prefix(es) covered by a valid ROA, 2 not-found.

PrefixRPKI stateReasonCovering VRP(s)
2001:b60::/32✓ validmatched VRP (correct origin, length within maxLength)AS20836 /32 maxLen 48 (ripe)
2a0a:ec00::/32- not-foundno covering VRP
2a07:2847::/32- not-foundno covering VRP
2001:b61::/32✓ validmatched VRP (correct origin, length within maxLength)AS20836 /32 maxLen 32 (ripe)
2a07:2840::/32✓ validmatched VRP (correct origin, length within maxLength)AS20836 /32 maxLen 32 (ripe)

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

We probed 29 arbitrary IPv6 address(es) inside AS20836's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2001:4c08::1b at hop 10 - that router answers ICMPv6 Echo. This is not in AS20836'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 honored. Forged ICMPv6 PTB (MTU=1280) was accepted by the destination's stack: the next 1500-byte Echo Reply arrived split into 2 fragments via the IPv6 Fragment Header.
method: ICMPv6 Echo + forged PTB, tested 2026-05-30T12:46:07Z

From NL host (go6lab)   openRFC 4890 ✓

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

4/4
Echo small (56B) 20.9ms
4/4
Echo 1500B (DF) 20.8ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
12a00:8642:42::31.0ms0%AS203993STEFFANN-DC-AS - S.J.M. Steffann, NL
2*-0%*-
32a00:1ca8:1::1942.7ms0%AS50673Serverius-as - Serverius Holding B.V., NL
42a03:3f40::10:412.0ms0%AS50673Serverius-as - Serverius Holding B.V., NL
5ix-ge-100-0-0-66.qhar2.ad1-amsterdam.ipv6.as6453.net
2a01:3e0:30:1::1
4.4ms0%AS6453AS6453 - TATA COMMUNICATIONS (AMERICA) INC, US
6if-bundle-2-2.qcore1.ad1-amsterdam.ipv6.as6453.net
2a01:3e0:701::7
3.0ms0%AS6453AS6453 - TATA COMMUNICATIONS (AMERICA) INC, US
7if-bundle-52-2.qcore2.av2-amsterdam.ipv6.as6453.net
2a01:3e0:701::11
4.0ms40%AS6453AS6453 - TATA COMMUNICATIONS (AMERICA) INC, US
8if-be-41-2.ecore1.av2-amsterdam.ipv6.as6453.net
2a01:3e0:ff40:100::5
3.5ms50%AS6453AS6453 - TATA COMMUNICATIONS (AMERICA) INC, US
9ae28.edge7.ams1.sp.lumen.tech
2001:1900:5:3::201
5.1ms0%AS3356LEVEL3 - Level 3 Parent, LLC, US
10lo0.0.edge1.Milan2.level3.net
2001:4c08::1b
32.1ms0%AS3356LEVEL3 - Level 3 Parent, LLC, US
112001:1900:5:2:2::510221.9ms0%AS3356LEVEL3 - Level 3 Parent, LLC, US
122001:b60:0:a01e::125.8ms0%AS20836CDLAN-AS - CDLAN SpA, IT
132001:b60:1200::129.9ms0%AS20836CDLAN-AS - CDLAN SpA, IT
142001:b60:1:4::126.1ms0%AS20836CDLAN-AS - CDLAN SpA, IT
15*-0%-
16*---
17*---
18*---
19*---
20*---
21*---
22*---
23*---
24*---

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

tracepath -6

 1?: [LOCALHOST]                        0.048ms pmtu 1500
 1:  2a00:8642:42::3                                       1.924ms 
 1:  2a00:8642:42::3                                       2.039ms 
 2:  no reply
 3:  2a00:1ca8:1::194                                      4.516ms 
 4:  2a03:3f40::10:41                                      3.691ms 
 5:  ix-et-9-1-2.tcore1.ad1-amsterdam.ipv6.as6453.net      7.648ms 
 6:  if-bundle-2-2.qcore1.ad1-amsterdam.ipv6.as6453.net    4.970ms 
 7:  if-bundle-52-2.qcore2.av2-amsterdam.ipv6.as6453.net   4.115ms 
 8:  no reply
 9:  ae28.edge7.ams1.sp.lumen.tech                         4.181ms asymm  7 
10:  lo0.0.edge1.Milan2.level3.net                        46.650ms asymm 12 
11:  2001:1900:5:2:2::5102                                23.165ms asymm 10 
12:  2001:b60:0:a01e::1                                   27.585ms asymm 11 
13:  2001:b60:1200::1                                     31.322ms asymm 12 
14:  2001:b60:1:4::1                                      27.116ms asymm 12 
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  no reply
23:  no reply
24:  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) 9.6ms
4/4
Echo 1500B (DF) 9.6ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1*---
2*---
3*---
4cdlan.minap.it
2001:7f8:c5::a502:836:1
9.3ms0%AS20836CDLAN s.r.l.
52001:b60:0:a01d::19.2ms0%AS20836CDLAN-AS - CDLAN SpA, IT
62001:b60:1200::19.2ms0%AS20836CDLAN-AS - CDLAN SpA, IT
72001:b60:1:4::19.3ms0%AS20836CDLAN-AS - CDLAN SpA, IT
8*-0%-
9*---
10*---
11*---
12*---
13*---
14*---
15*---
16*---
17*---
18*---
19*---
20*---
21*---
22*---
23*---
24*---

tracepath -6

 1?: [LOCALHOST]                        0.031ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        2.050ms 
 2:  2a12:d8c0:109f:121::a1                                3.029ms 
 3:  2a12:d8c0:101f:6::1                                  10.407ms 
 4:  cdlan.minap.it                                        9.990ms asymm  5 
 5:  2001:b60:0:a01d::1                                    9.886ms asymm  6 
 6:  2001:b60:1200::1                                      9.816ms asymm  7 
 7:  2001:b60:1:4::1                                       9.948ms asymm  8 
 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
23:  no reply
24:  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) 10.2ms
4/4
Echo 1500B (DF) 10.2ms
no
Type 1 dest-unreach
443
TCP responds on

Path (traceroute + mtr + PTR)

#IP / PTRRTTmtr lossASAS holder
1fw1-lju.6connect.com
2607:fae0:a000::2
0.3ms0%*AS80386CONNECT - 6connect, Inc., US
2*-0%*-
32a03:a100:0:201:1::10.9ms80%AS56635XENYA - XENYA inzeniring, proizvodnja in trgovina, d.o.o. Ljubljana, SI
4e0-1.core1.lju1.he.net
2001:470:1:5be::1
1.9ms0%AS6939HURRICANE - Hurricane Electric LLC, US
5*---
6port-channel1.core1.zag2.he.net
2001:470:0:2ea::2
4.3ms40%AS6939HURRICANE - Hurricane Electric LLC, US
7*---
8cdlan.topix.it
2001:7f8:23:ffff::86
10.5ms0%-NA
92001:b60:0:a01d::110.2ms0%AS20836CDLAN-AS - CDLAN SpA, IT
102001:b60:1200::110.3ms0%AS20836CDLAN-AS - CDLAN SpA, IT
112001:b60:1:4::110.1ms0%AS20836CDLAN-AS - CDLAN SpA, IT
12*-0%-
13*---
14*---
15*---
16*---
17*---
18*---
19*---
20*---
21*---
22*---
23*---
24*---

Rate-limited ICMPv6: hop 3, hop 6 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.031ms pmtu 1500
 1:  fw1-lju.6connect.com                                  4.314ms 
 1:  fw1-lju.6connect.com                                  0.960ms 
 2:  no reply
 3:  no reply
 4:  e0-1.core1.lju1.he.net                                2.262ms 
 5:  no reply
 6:  port-channel1.core1.zag2.he.net                       3.964ms 
 7:  no reply
 8:  cdlan-v6.mix-it.net                                  10.485ms asymm  6 
 9:  2001:b60:0:a01d::1                                   10.257ms asymm  8 
10:  2001:b60:1200::1                                     15.331ms 
11:  2001:b60:1:4::1                                      10.957ms asymm 10 
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
23:  no reply
24:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500