AS47217 - PLANETEL-SPA Planetel SPAPARFC 4890 ✓RPKI ⚠ 2/3ASPA -

AS overview

Test target: 2a02:670:d000:400::7 · ipv6.planetel.it · address space: PA · prefixes announced: 3

prefix(es): 2a02:670::/32, 2a02:5c80::/32, 2a0a:27c0::/32

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 AS47217's announced prefix replied during the random-target probe. Hop(s): 2a02:670::, 2a02:670:f000:a::19, 2a02:670:f000:a::b. 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:

• NL host (go6lab): Type 2 honored. Forged PTB accepted; next response shrunk. (ICMPv6 Echo + forged PTB)
• ITA host (Karsolink): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (TLS handshake + forged PTB)
• SLO host (6connect): Type 2 honored. Forged PTB accepted; next response shrunk. (ICMPv6 Echo + forged PTB)

Why they disagree - different probe methods: These vantages picked different probe methods, so their verdicts are not directly comparable. The active test tries methods in order (icmp6-echo → dns-tcp → tls → http) and stops at the first that produces a definitive verdict; if the chosen method differs, the underlying evidence differs too. Most often this is because the path PMTU on one vantage is below 1500 B, so the natural Echo Reply is already fragmented and the icmp6-echo method falls through to a TCP-based one. This is largely a measurement artifact, not a destination-behaviour difference.

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)'

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)'

From NL host (go6lab)   openRFC 4890 ✓

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

Path (traceroute + mtr + PTR)

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

tracepath -6

 1?: [LOCALHOST]                        0.036ms pmtu 1500
 1:  2a00:8642:42::3                                       2.285ms 
 1:  2a00:8642:42::3                                       1.793ms 
 2:  gw.friends.steffann.nl                                2.470ms 
 3:  2a00:1ca8:1::194                                      3.560ms 
 4:  2a03:3f40::10:33                                      6.017ms 
 5:  ae1-499.RT.SRV.DRO.NL.retn.net                        4.896ms 
 6:  RT.MIX.MIL.IT.retn.net                               19.625ms 
 7:  GW-AS47217.retn.net                                  20.941ms 
 8:  2a02:670:f000:a::12                                  21.217ms asymm  7 
 9:  2a02:670:f001::3                                     20.888ms asymm  8 
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     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 (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                        0.733ms 
 1:  karsolink-01.net.karsolink.com                        0.803ms 
 2:  2a12:d8c0:109f:121::a1                                0.833ms 
 3:  2a12:d8c0:101f:103::1                                 8.927ms 
 4:  planetel-v6.mix-it.net                               10.211ms 
 5:  2a02:670:f000:a::12                                  11.147ms 
 6:  2a02:670:f001::3                                      9.983ms 
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     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]                        0.028ms pmtu 1500
 1:  fw1-lju.6connect.com                                  0.636ms 
 1:  fw1-lju.6connect.com                                  0.639ms 
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 3:  2a03:a100:0:201:1::1                                  1.099ms 
 4:  e0-1.core1.lju1.he.net                                2.512ms 
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 6:  port-channel1.core1.zag2.he.net                       3.924ms 
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 8:  2001:7f8:c0::4:7217:1                                11.212ms asymm  6 
 9:  2a02:670:f000:a::12                                  12.397ms asymm  7 
10:  2a02:670:f001::3                                     11.471ms asymm  9 
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     Too many hops: pmtu 1500
     Resume: pmtu 1500