AS51185 - MAINSTREAMING-AS MainStreaming SpARFC 4890 ✓RPKI ✓ 21/21ASPA -

AS overview

Test target: 2a02:2890:efff::1 · static prefix probe · address space: unknown · prefixes announced: 21

prefix(es): 2a02:2891:157::/48, 2a02:2891:9::/48, 2a02:2891:160::/48, 2a02:2890:efff::/48, 2a02:2891:10::/48, 2a02:2891:4::/48, 2a02:2891:16::/48, 2a02:2891:18::/48 (+13 more)

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 70 arbitrary IPv6 address(es) inside AS51185's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2001:2034:a:2a1::1 at hop 11 - that router answers ICMPv6 Echo. This is not in AS51185'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:

• SRB host (SOX, Belgrade): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
• DE host (Berlin): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
• DE host (Düsseldorf): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
• NL host (go6lab): inconclusive: no Echo Reply to 1300-byte probe. (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 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (ICMPv6 Echo + forged PTB)
• SLO host (T-2): Type 2 NOT honored. Forged PTB had no effect (filtered en route or stack ignored it). (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]                        0.011ms pmtu 1500
 1:  _gateway                                              0.798ms 
 1:  _gateway                                              0.581ms 
 2:  sox-pn.sox.rs                                         0.441ms 
 3:  2001:7f8:1e:8::3d                                     0.727ms asymm  2 
 4:  ae8-930.RT.IRX.VIE.AT.retn.net                       12.874ms asymm  3 
 5:  RT.THV.PAR.FR.retn.net                               35.208ms asymm  4 
 6:  mainstreaming.par.franceix.net                       36.027ms asymm  5 
 7:  2001:7f8:1::a505:1185:1                              33.111ms asymm 10 
 8:  2a02:2890:0:100::5:99                                35.082ms asymm  6 
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  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]                        0.027ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.507ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.499ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.945ms 
 3:  ae0-150.cr10.fra01.lwlcom.net                        10.307ms asymm  7 
 4:  ae0-20.cr10.fra07.lwlcom.net                         10.613ms asymm  6 
 5:  2a02:2890::100:3:0:2a                                10.533ms asymm  7 
 6:  2a02:2890:0:100::5:197                               10.833ms asymm  8 
 7:  2a02:2890:0:100::5:71                                10.679ms asymm  9 
 8:  2a02:2890:0:100::5:99                                10.805ms asymm 10 
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  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]                        0.018ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.226ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.224ms 
 2:  ipv6.de-cix.dus.de.as51185.onecom.global              1.202ms asymm  5 
 3:  2a02:2890:0:100::5:102                                1.156ms asymm  6 
 4:  no reply
 5:  no reply
 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
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From NL host (go6lab)   all blocked

filter likely at: before path completes · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.041ms pmtu 1500
 1:  2a00:8642:42::2                                       2.764ms 
 1:  2a00:8642:42::2                                       5.628ms 
 2:  no reply
 3:  ccr2-ccr1.dc1.nogalliance.org                         3.232ms asymm  2 
 4:  2001:7f8:1::a505:1185:1                               5.456ms asymm  5 
 5:  2a02:2890:0:100::5:1b9                                6.628ms asymm  6 
 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
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From ITA host (Karsolink)   echo onlyRFC 4890 ✓

filter likely at: unknown · min PMTU on path: 1500

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.032ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.620ms 
 1:  karsolink-01.net.karsolink.com                        0.785ms 
 2:  2a12:d8c0:109f:121::a1                                0.661ms 
 3:  no reply
 4:  onecomglobal.minap.it                                11.033ms 
 5:  mainstreaming-AS51185.mix-it.net                      9.654ms asymm  4 
 6:  2a02:2890:0:100:0:7:0:36                             10.237ms asymm  5 
 7:  2a02:2890:0:100:0:7:0:142                            10.611ms asymm  5 
 8:  no reply
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500 

From SLO host (6connect)   echo onlyRFC 4890 ✗

filter likely at: unknown · 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]                        0.023ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.654ms 
 1:  fw1-lju.6connect.com                                  0.445ms 
 2:  ccr-to-fw-ccr1-gw-lju.6connect.com                    1.043ms 
 3:  no reply
 4:  2a00:ee0:1:15::2                                      1.505ms asymm  3 
 5:  2a00:ee0:1:15::2                                      1.610ms pmtu 1500
 5:  mainstreaming.interxionfra11.nlsix.net               23.296ms asymm  6 
 6:  as51185.locix.online                                 14.298ms asymm  8 
 7:  2a02:2890:0:100::5:99                               268.877ms 
 8:  no reply
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  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]                        0.026ms pmtu 1500
 1:  2a01:261:313:b814::1                                  0.766ms 
 1:  no reply
 2:  2a01:260:1::225                                       3.509ms 
 3:  2a01-260-1-1--9c.core6.t-2.net                        3.141ms 
 4:  2a01-260-1-1--39.core6.t-2.net                        2.973ms asymm  3 
 5:  onecom.interxionfra11.nlsix.net                      27.333ms asymm  4 
 6:  2a02:2890:0:100::5:99                                27.346ms asymm  5 
 7:  2a02:2890:0:100::5:99                                27.773ms asymm  5 
 8:  no reply
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500