AS200409 - Tecnodata Tecnodata Trentina SrlPARFC 4890 ✓RPKI ✓ 1/1ASPA ✓

AS overview

Test target: 2a0c:ea40:1003::11 · ns1.tecnotn.net · address space: PA · prefixes announced: 1

prefix(es): 2a0c:ea40::/29

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

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

At least one router inside AS200409's announced prefix replied during the random-target probe. Hop(s): 2a0c:ea40::1, 2a0c:ea40::2, 2a0c:ea40::77:83:112:2. 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): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (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 - path-asymmetric Type 2 filtering: Both vantages used the ICMPv6 Echo + forged-PTB method on the same destination IP, but reached different verdicts. The destination's stack is the same in both cases - so the difference is in the path: a transit AS on one route filters our forged Type 2 (or its return ICMPv6 carrying the embedded packet) while the other route delivers it intact. The vantage that says honored shows what the destination's stack actually does; the one that says not honored shows that the path between us and them drops Type 2.

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)'

sudo ip6tables -L INPUT -nv | grep -iE 'icmpv6|packet-too-big'
sudo nft list ruleset 2>/dev/null | grep -A1 'icmpv6'

sudo sysctl net.ipv6.conf.all.accept_redirects net.ipv4.ip_no_pmtu_disc net.ipv6.route.mtu_expires

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)'

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.013ms pmtu 1500
 1:  _gateway                                              0.541ms 
 1:  _gateway                                              0.468ms 
 2:  2001:7f8:1e::4                                        0.652ms 
 3:  2001:7f8:30:0:2:1:0:9002                             12.948ms 
 4:  RT.MIX.MIL.IT.retn.net                               55.789ms 
 5:  GW-AS200409.retn.net                                 28.893ms 
 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 1500
     Resume: pmtu 1500 

From DE host (Berlin)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.022ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.436ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.429ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.923ms 
 3:  retn.bcix.de                                         10.564ms asymm  5 
 4:  RT.MIX.MIL.IT.retn.net                               19.512ms asymm  5 
 5:  GW-AS200409.retn.net                                 19.199ms asymm 11 
 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 1500
     Resume: pmtu 1500 

From DE host (Düsseldorf)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.015ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.447ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.370ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            2.552ms 
 3:  no reply
 4:  lag11.core3-dus1.bb.wiit.network                      0.398ms 
 5:  lag0-vl1011.core1-fra-ix.bb.wiit.network              4.349ms 
 6:  lag0-vl1001.core1-nbg-ncd.bb.wiit.network             7.032ms 
 7:  lag0-vl6.core2-nbg-ncd.bb.wiit.network                7.213ms 
 8:  lag0-vl1006.core2-muc2.bb.wiit.network                9.611ms 
 9:  lag0-vl1009.core1-muc-eq3.bb.wiit.network             9.982ms 
10:  lag0-vl1001.core1-pda-vsix.bb.wiit.network           20.436ms 
11:  lag0-vl1001.core1-mil-mix.bb.wiit.network            20.194ms asymm  9 
12:  tecnodatatrentina-v6.mix-it.net                      20.452ms asymm 10 
13:  no reply
14:  no reply
15:  no reply
16:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From NL host (go6lab)   openRFC 4890 ✗

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.033ms pmtu 1500
 1:  2a00:8642:42::2                                       3.666ms 
 1:  2a00:8642:42::2                                       2.577ms 
 2:  gw.friends.steffann.nl                                5.112ms 
 3:  ccr2-ccr1.dc1.nogalliance.org                         2.668ms asymm  2 
 4:  ams-ix.retn.net                                       6.207ms asymm  7 
 5:  RT.MIX.MIL.IT.retn.net                               21.013ms asymm  6 
 6:  GW-AS200409.retn.net                                 28.048ms asymm  7 
 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 1500
     Resume: pmtu 1500 

From ITA host (Karsolink)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

Rate-limited ICMPv6: hop 3, hop 4, hop 6 (loss between 5% and 95% across mtr cycles - the router replies but only sometimes).

tracepath -6

 1?: [LOCALHOST]                        0.036ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.703ms 
 1:  karsolink-01.net.karsolink.com                        0.631ms 
 2:  2a12:d8c0:109f:121::a1                                0.770ms 
 3:  2a12:d8c0:109f:106::a2                                3.499ms 
 4:  fastweb.minap.it                                     11.135ms 
 5:  2001:b00:1:1:3::135                                   9.489ms 
 6:  2001:b00:1:1:1::1c3                                   9.106ms 
 7:  2a0c.ea40.ip6.tecnotn.net                            10.175ms asymm  5 
 8:  2a0c.ea40.ip6.tecnotn.net                            10.257ms asymm  4 
 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 1500
     Resume: pmtu 1500 

From SLO host (6connect)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.031ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.476ms 
 1:  fw1-lju.6connect.com                                  0.515ms 
 2:  no reply
 3:  2a00:ee1:800:9::1                                     1.993ms 
 4:  2a00:ee0:1:10::2                                      1.557ms asymm  3 
 5:  2a00:ee0:1:15::2                                      1.706ms pmtu 1500
 5:  de-cix1.rt.act.fkt.de.retn.net                       14.138ms asymm  9 
 6:  RT.MIX.MIL.IT.retn.net                               15.953ms asymm  8 
 7:  GW-AS200409.retn.net                                 14.495ms asymm  6 
 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 1500

From SLO host (T-2)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.027ms pmtu 1500
 1:  2a01:261:313:b814::1                                  0.973ms 
 1:  2a01:261:313:b814::1                                  0.912ms 
 2:  2a01:260:1::225                                       2.566ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        2.820ms 
 4:  2001:7f8:46:0:1::3303                                10.537ms 
 5:  i00mil-005-loo179.bb.ip-plus.net                     10.395ms 
 6:  2001:4d98:a000::119                                 127.246ms asymm 11 
 7:  2001:b00:1:1:3::13b                                  15.689ms asymm  8 
 8:  2001:b00:1:1:1::1c3                                  15.503ms asymm  9 
 9:  2a0c.ea40.ip6.tecnotn.net                            14.873ms asymm  8 
10:  2a0c.ea40.ip6.tecnotn.net                            15.372ms asymm  7 
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500