AS49432 - SCHALLERT-AS Dominic Schallert trading as schallert.com e.UPIRFC 4890 ✓RPKI ✓ 1/1ASPA ✓

AS overview

Test target: 2001:678:118c:200::66 · mail.schallert.com · address space: PI · prefixes announced: 1

prefix(es): 2001:678:118c::/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 AS49432's announced prefix(es). No router inside the prefix responded. The deepest visible hop was 2a02:1688:0:1025::1 at hop 14 - that router answers ICMPv6 Echo. This is not in AS49432'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 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)

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

tracepath -6

 1?: [LOCALHOST]                        0.012ms pmtu 1500
 1:  _gateway                                              0.409ms 
 1:  _gateway                                              0.456ms 
 2:  sox-pn.sox.rs                                         0.326ms 
 3:  2001:7f8:1e:8::3d                                     0.695ms asymm  2 
 4:  ae8-930.RT.IRX.VIE.AT.retn.net                       11.136ms asymm  3 
 5:  RT.IRX.FKT.DE.retn.net                               22.168ms asymm  4 
 6:  2a02:1688:0:1003::                                   28.726ms asymm 12 
 7:  2a02:1688:0:1003::1                                  27.784ms asymm 13 
 8:  dmz-fw.schallert.com                                 30.342ms asymm 14 
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  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]                        0.013ms pmtu 1500
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.518ms 
 1:  xe-0-0-13-178.gw01.ber01.as59645.net                  0.626ms 
 2:  ae0-2453.cr10.ber01.lwlcom.net                        0.950ms 
 3:  ae0-40.cr10.muc02.lwlcom.net                         11.799ms 
 4:  ae0-10.cr10.muc01.lwlcom.net                         11.733ms 
 5:  2a00:c380:f001::eb                                   11.973ms 
 6:  ipv6.core.as31543.net                                12.703ms 
 7:  ipv6.core.as31543.net                                16.058ms asymm 12 
 8:  ipv6.core.as31543.net                                16.840ms asymm 12 
 9:  ipv6.core.as31543.net                                21.230ms asymm  7 
10:  ipv6.core.as31543.net                                23.518ms asymm  6 
11:  ipv6.core.as31543.net                                22.130ms asymm  7 
12:  ipv6.core.as31543.net                                23.556ms asymm  8 
13:  2a00:15c0:1:7::2                                     18.547ms asymm 10 
14:  2a02:1688:0:1025::1                                  18.667ms asymm 11 
15:  core2.as49432.net                                    19.292ms asymm 10 
16:  dmz-fw.schallert.com                                 19.709ms asymm 10 
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  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]                        0.013ms pmtu 1500
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.382ms 
 1:  xe-0-0-12-142.gw01.dus01.as59645.net                  0.267ms 
 2:  eth1-0-12-h5594.edge5-dus1.bb.wiit.network            1.139ms 
 3:  no reply
 4:  lag11.core3-dus1.bb.wiit.network                      0.444ms 
 5:  lag2.core1-dus-ix.bb.wiit.network                     0.632ms 
 6:  2a02:1688:0:1003::                                   13.381ms asymm  7 
 7:  2a02:1688:0:1003::1                                  13.661ms asymm  8 
 8:  dmz-fw.schallert.com                                 14.067ms asymm  9 
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  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]                        1.281ms pmtu 1500
 1:  2a00:8642:42::2                                       2.362ms 
 1:  2a00:8642:42::2                                       1.832ms 
 2:  gw.friends.steffann.nl                                4.028ms 
 3:  ccr2-ccr1.dc1.nogalliance.org                         4.518ms asymm  2 
 4:  2a02:1688:0:1003::                                   22.478ms asymm  7 
 5:  2a02:1688:0:1003::1                                  20.258ms asymm  8 
 6:  dmz-fw.schallert.com                                 23.086ms asymm  9 
 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
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  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]                        0.031ms pmtu 1500
 1:  karsolink-01.net.karsolink.com                        0.749ms 
 1:  karsolink-01.net.karsolink.com                        0.629ms 
 2:  2a12:d8c0:109f:121::a1                                0.542ms 
 3:  no reply
 4:  mynet-gmbh-v6.mix-it.net                             14.483ms 
 5:  ipv6.core.as31543.net                                15.525ms 
 6:  ipv6.core.as31543.net                                24.977ms 
 7:  ipv6.core.as31543.net                                16.435ms 
 8:  ipv6.core.as31543.net                                18.740ms asymm  6 
 9:  ipv6.core.as31543.net                                17.433ms asymm  7 
10:  ipv6.core.as31543.net                                18.501ms asymm  8 
11:  2a00:15c0:1:7::2                                     15.433ms asymm  7 
12:  r2.ufdroht.net                                       15.682ms asymm  8 
13:  core2.as49432.net                                    22.263ms asymm  8 
14:  dmz-fw.schallert.com                                 22.638ms asymm  8 
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  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]                        0.034ms pmtu 9000
 1:  fw1-lju.6connect.com                                  0.699ms 
 1:  fw1-lju.6connect.com                                  0.602ms 
 2:  no reply
 3:  no reply
 4:  2a00:ee0:1:10::2                                    134.481ms asymm  3 
 5:  2a00:ee0:1:10::2                                      1.356ms pmtu 1500
 5:  2a02:1688:0:1003::                                   19.774ms asymm 13 
 6:  2a02:1688:0:1003::1                                  19.962ms asymm 14 
 7:  dmz-fw.schallert.com                                 20.258ms asymm 15 
 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
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  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)

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

tracepath -6

 1?: [LOCALHOST]                        0.012ms pmtu 1500
 1:  no reply
 2:  2a01:260:1::225                                       5.902ms 
 3:  2a01-260-1-1--9a.core6.t-2.net                        2.889ms 
 4:  2a01-260-1-1--38.core6.t-2.net                        2.212ms asymm  3 
 5:  100ge0-0-0-31.core1.vie1.he.net                       9.533ms 
 6:  2001:7f8:30:0:2:1:3:1543                             20.626ms asymm  5 
 7:  2001:7f8:30:0:2:1:3:1543                             20.417ms asymm  5 
 8:  ipv6.core.as31543.net                                20.503ms asymm  6 
 9:  ipv6.core.as31543.net                                22.954ms asymm  8 
10:  2a00:15c0:1:7::2                                     39.495ms asymm 12 
11:  2a00:15c0:1:7::6                                     34.013ms asymm 13 
12:  2a00:15c0:1:7::6                                     33.292ms asymm 13 
13:  core2.as49432.net                                    20.689ms asymm  7 
14:  dmz-fw.schallert.com                                 21.519ms asymm  7 
15:  no reply
16:  no reply
17:  no reply
18:  no reply
19:  no reply
20:  no reply
21:  no reply
22:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500