AS219198 - OMC-AT open mind consultingPI/PARFC 4890 ✓RPKI ✓ 1/1ASPA -

AS overview

Test target: 2001:67c:1b44::1 · static prefix probe · address space: mixed · prefixes announced: 1

prefix(es): 2001:67c:1b44::/48

VIX / AAIX / SAIX / TIROL-IX / ERA-IX peering

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

We probed 35 arbitrary IPv6 address(es) inside AS219198's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a0d:6c07:ffff:914::2 at hop 18 - that router answers ICMPv6 Echo. This is not in AS219198'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): 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]                        0.016ms pmtu 1500
 1:  _gateway                                              0.361ms 
 1:  _gateway                                              0.414ms 
 2:  2001:7f8:1e::4                                        0.531ms 
 3:  vix-v6-v912.xenox-it.at                              12.980ms 
 4:  rr2v912.vix2.xenox-it.at                             11.661ms 
 5:  dr2v914.vix2.xenox-it.at                             13.436ms 
 6:  no reply
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24:  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]                        0.016ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.434ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.540ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.813ms 
 3:  ae3-90.cr10.ham01.lwlcom.net                          5.133ms 
 4:  ae0-50.cr11.ham01.lwlcom.net                          5.123ms 
 5:  2a00:c380:f000::4b                                    5.527ms asymm  4 
 6:  ae4-2087.dus10.core-backbone.com                     11.666ms asymm  5 
 7:  ae43-2026.fra30.core-backbone.com                    11.606ms asymm  5 
 8:  ae16-2123.fra40.core-backbone.com                    11.434ms asymm  6 
 9:  ae8-2027.muc10.core-backbone.com                     15.550ms asymm  8 
10:  ae1-2030.muc20.core-backbone.com                     15.637ms asymm  7 
11:  ae4-2057.slz10.core-backbone.com                     17.285ms asymm  8 
12:  ae2-2058.vie20.core-backbone.com                     21.089ms asymm  9 
13:  2a01:4a0:1338:1db::2                                 20.937ms asymm 10 
14:  rr1v853.vix3.mmc.at                                  21.567ms asymm  6 
15:  dr1v870.vix3.mmc.at                                  22.009ms asymm  7 
16:  br1v704.vix3.xenox-it.at                             22.319ms asymm  8 
17:  rr2v910.vix2.xenox-it.at                             22.421ms asymm  6 
18:  dr2v914.vix2.xenox-it.at                             21.994ms asymm  7 
19:  no reply
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22:  no reply
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24:  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]                        0.020ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.308ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.427ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            1.105ms 
 3:  no reply
 4:  lag30.core3-dus1.bb.wiit.network                      0.357ms 
 5:  lag8.core1-dus-ix.bb.wiit.network                     0.509ms 
 6:  core-backbone-dus-gw.bb.wiit.network                 10.377ms 
 7:  ae43-2026.fra30.core-backbone.com                    10.123ms asymm  6 
 8:  ae16-2123.fra40.core-backbone.com                    10.020ms asymm  7 
 9:  ae8-2027.muc10.core-backbone.com                     14.559ms 
10:  ae1-2030.muc20.core-backbone.com                     14.538ms asymm  8 
11:  ae4-2057.slz10.core-backbone.com                     16.076ms asymm  9 
12:  ae2-2058.vie20.core-backbone.com                     19.879ms asymm 10 
13:  2a01:4a0:1338:1db::2                                 19.803ms asymm 11 
14:  rr1v853.vix3.mmc.at                                  20.441ms asymm  7 
15:  dr1v870.vix3.mmc.at                                  20.386ms asymm  8 
16:  br1v704.vix3.xenox-it.at                             20.827ms asymm  9 
17:  rr2v910.vix2.xenox-it.at                             20.618ms asymm  7 
18:  dr2v914.vix2.xenox-it.at                             21.073ms asymm  8 
19:  no reply
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24:  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]                        0.072ms pmtu 1500
 1:  2a00:8642:42::2                                       2.210ms 
 1:  2a00:8642:42::2                                       2.101ms 
 2:  gw.friends.steffann.nl                                5.207ms 
 3:  2a00:1ca8:1::194                                      5.914ms 
 4:  2a03:3f40::10:33                                      9.915ms 
 5:  ae1-499.RT.SRV.DRO.NL.retn.net                        5.573ms 
 6:  RT.IRX.VIE.AT.retn.net                               21.916ms 
 7:  vix-v6-v912.xenox-it.at                              22.082ms 
 8:  rr1v912.vix3.xenox-it.at                             22.130ms 
 9:  dr2v914.vix2.xenox-it.at                             22.875ms 
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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

Path (traceroute + mtr + PTR)

tracepath -6

 1?: [LOCALHOST]                        0.030ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.672ms 
 1:  no reply
 2:  2a12:d8c0:109f:121::a1                                0.685ms 
 3:  2a12:d8c0:101f:103::1                                 8.827ms 
 4:  ae8-202.RT.CLR.MIL.IT.retn.net                        8.336ms asymm  5 
 5:  RT.IRX.VIE.AT.retn.net                               11.809ms 
 6:  vix-v6-v912.xenox-it.at                              16.223ms 
 7:  rr1v912.vix3.xenox-it.at                             16.421ms 
 8:  dr2v914.vix2.xenox-it.at                             12.408ms 
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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]                        0.082ms pmtu 9000
 1:  fw1-lju.6connect.com                                  3.120ms 
 1:  fw1-lju.6connect.com                                  0.544ms 
 2:  ccr-to-fw-ccr1-gw-lju.6connect.com                    0.924ms 
 3:  no reply
 4:  2a00:ee0:1:15::2                                      1.523ms asymm  3 
 5:  2a00:ee0:1:15::2                                      1.828ms pmtu 1500
 5:  2a11:4142:2002::                                      1.173ms asymm  6 
 6:  r2-vie1-at.as5405.net                                 7.370ms asymm  8 
 7:  et9-4096.r2-vie2-at.as5405.net                        7.296ms asymm  8 
 8:  vix-v6-v912.xenox-it.at                             106.340ms asymm  5 
 9:  rr1v912.vix3.xenox-it.at                              8.447ms asymm  6 
10:  dr2v914.vix2.xenox-it.at                              9.035ms asymm  7 
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     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                                  0.880ms 
 1:  2a01:261:313:b814::1                                  0.848ms 
 2:  2a01:260:1::225                                       2.477ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        2.746ms 
 4:  2a01-260-1-1--c.core6.t-2.net                         5.430ms 
 5:  vix-v6-v912.xenox-it.at                               8.106ms 
 6:  vix-v6-v912.xenox-it.at                               8.965ms asymm  5 
 7:  rr1v912.vix3.xenox-it.at                              9.349ms asymm  6 
 8:  no reply
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     Too many hops: pmtu 1500
     Resume: pmtu 1500