AS34691 - TLCWEB-AS Intendo S.r.lPARPKI -ASPA -

AS overview

Test target: 2a12:c8c0:20::1 · (no live host found) · address space: PA · prefixes announced: 1

prefix(es): 2a12:c8c0:20::/48

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

We probed 15 arbitrary IPv6 address(es) inside AS34691's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2001:1bd0:0:2::13 at hop 7 - that router answers ICMPv6 Echo. This is not in AS34691'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

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): inconclusive: no Echo Reply to 1300-byte probe. (ICMPv6 Echo + forged PTB)
• ITA host (Karsolink): inconclusive: no Echo Reply after PTB (probe 1500B). (ICMPv6 Echo + forged PTB)
• SLO host (6connect): inconclusive: no Echo Reply to 1300-byte probe. (ICMPv6 Echo + forged PTB)

Why they disagree - reachability mismatch: One vantage couldn't drive a flow at all to this destination (no Echo Reply or no responding TCP port), so the active test had no behavioural change to observe. The other vantage's verdict is the only meaningful one here.

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)   transit only unreachable

filter likely at: past AS174 (COGENT-174) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

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

tracepath -6

 1?: [LOCALHOST]                        0.055ms pmtu 1500
 1:  2a00:8642:42::3                                       1.408ms 
 1:  2a00:8642:42::3                                       1.139ms 
 2:  gw.friends.steffann.nl                                1.860ms 
 3:  2a00:1ca8:1::194                                      2.893ms 
 4:  2a03:3f40::10:41                                      2.704ms 
 5:  no reply
 6:  no reply
 7:  no reply
 8:  no reply
 9:  2001:978:2:40::3:1                                    7.032ms !N
     Resume: pmtu 1500 

From ITA host (Karsolink)   transit only unreachable

filter likely at: no path · 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]                        0.029ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.545ms 
 1:  karsolink-01.net.karsolink.com                        0.573ms 
 2:  2a12:d8c0:109f:121::a1                                1.020ms 
 3:  2a12:d8c0:101f:6::1                                  10.123ms 
 4:  2a03:b020:1:51::a                                    10.425ms 
 5:  2a03:b020::254                                       18.644ms asymm  7 
 6:  retelit.rom.namex.it                                 20.013ms asymm  8 
 7:  2001:1bd0:0:2::13                                    19.914ms 
 8:  2a12:c8c0:20::1                                      27.196ms reached
     Resume: pmtu 1500 hops 8 back 8 

From SLO host (6connect)   transit only unreachable

filter likely at: past AS8038 (6CONNECT) · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.033ms pmtu 1500
 1:  fw1-lju.6connect.com                                  0.491ms 
 1:  fw1-lju.6connect.com                                  0.477ms 
 2:  ccr-to-fw-ccr1-gw-lju.6connect.com                    0.594ms !N
     Resume: pmtu 1500