ÚLTIMA BREAKTHROUGH - > veja os resultados tshark abaixo para alguma pista
Olá, em casa, tenho a seguinte configuração:
Internet - NAS (Ubuntu 16.04.4 LTS) - LAN (Asus N56U WiFi) - usuários da família. NAS conecta usando pppoe (ppp0, cabo) para a Internet, tendo eth0 (192.168.0.1, cabo) para a LAN. O Asus N56U conecta-se ao NAS usando o ip estático 192.168.0.2/255.255.255.0 com o DNS 192.168.0.1.
Tudo funciona bem:
NAS & usuários da família acessam a Internet enquanto acessam a Internet NAS.
Eu também tenho outro roteador extremamente similar (Asus RT-AC66U) que simplesmente trocando com o Asus N56U enquanto mantém as mesmas configurações simples não funciona :(. Quero dizer qualquer coisa que toca a Internet morre embora meus sites pessoais ainda sejam acessíveis pela LAN.
Eu tentei este comando no NAS (108.177.119.94 é www.google.ro):
sudo tcpdump -AX -vnni eth0 -c 2 dst 108.177.119.94
ao executar isso em roteadores (eu tenho acesso telnet a eles):
ping -c 2 108.177.119.94
e eu entendo isso para o N56U:
09:00:47.036839 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.0.2 > 108.177.119.94: ICMP echo request, id 63814, seq 0, length 64
0x0000: 4500 0054 0000 4000 4001 95ef c0a8 0002 E..T..@.@.......
0x0010: 6cb1 775e 0800 d64a f946 0000 7cd9 ab94 l.w^...J.F..|...
0x0020: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0030: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0040: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0050: 0000 0000 ....
09:00:48.044176 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.0.2 > 108.177.119.94: ICMP echo request, id 63814, seq 1, length 64
0x0000: 4500 0054 0000 4000 4001 95ef c0a8 0002 E..T..@.@.......
0x0010: 6cb1 775e 0800 95eb f946 0001 ad37 bb94 l.w^.....F...7..
0x0020: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0030: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0040: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0050: 0000 0000 ....
e isto para AC66U (o problemático):
09:07:16.655875 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.0.2 > 108.177.119.94: ICMP echo request, id 27906, seq 0, length 64
0x0000: 4500 0054 0000 4000 4001 95ef c0a8 0002 E..T..@.@.......
0x0010: 6cb1 775e 0800 638c 6d02 0000 de6b 4905 l.w^..c.m....kI.
0x0020: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0030: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0040: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0050: 0000 0000 ....
09:07:17.668123 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.0.2 > 108.177.119.94: ICMP echo request, id 27906, seq 1, length 64
0x0000: 4500 0054 0000 4000 4001 95ef c0a8 0002 E..T..@.@.......
0x0010: 6cb1 775e 0800 7e18 6d02 0001 b4de 5805 l.w^..~.m.....X.
0x0020: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0030: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0040: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0050: 0000 0000 ....
Com o N56U eu vejo (usando tcpdump ) a requisição viajando de eth0 a ppp0 para Internet e back; com AC66U o resultado acima é tudo que vejo (o pedido é recebido por eth0 e depois nada).
O que poderia ser o problema?
EDIT4 (abaixo apontei um possível problema)
Outra maneira de visualizar os resultados acima (já salvos como arquivos * .pcap) é com tshark (somente o 1o frame).
Para o N56U, obtenho:
$tshark -r n56u-eth0-dst.pcap -V
Frame 1: 98 bytes on wire (784 bits), 98 bytes captured (784 bits)
Encapsulation type: Ethernet (1)
Arrival Time: May 5, 2018 09:00:47.036839000 EEST
[Time shift for this packet: 0.000000000 seconds]
Epoch Time: 1525500047.036839000 seconds
[Time delta from previous captured frame: 0.000000000 seconds]
[Time delta from previous displayed frame: 0.000000000 seconds]
[Time since reference or first frame: 0.000000000 seconds]
Frame Number: 1
Frame Length: 98 bytes (784 bits)
Capture Length: 98 bytes (784 bits)
[Frame is marked: False]
[Frame is ignored: False]
[Protocols in frame: eth:ethertype:ip:icmp:data]
Ethernet II, Src: Motorola_1b:ed:f2 (98:0c:a5:1b:ed:f2), Dst: AsrockIn_7c:28:bf (d0:50:99:7c:28:bf)
Destination: AsrockIn_7c:28:bf (d0:50:99:7c:28:bf)
Address: AsrockIn_7c:28:bf (d0:50:99:7c:28:bf)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Source: Motorola_1b:ed:f2 (98:0c:a5:1b:ed:f2)
Address: Motorola_1b:ed:f2 (98:0c:a5:1b:ed:f2)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
Internet Protocol Version 4, Src: 192.168.0.2, Dst: 108.177.119.94
0100 .... = Version: 4
.... 0101 = Header Length: 20 bytes (5)
Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
0000 00.. = Differentiated Services Codepoint: Default (0)
.... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
Total Length: 84
Identification: 0x0000 (0)
Flags: 0x02 (Don't Fragment)
0... .... = Reserved bit: Not set
.1.. .... = Don't fragment: Set
..0. .... = More fragments: Not set
Fragment offset: 0
Time to live: 64
Protocol: ICMP (1)
Header checksum: 0x95ef [validation disabled]
[Header checksum status: Unverified]
Source: 192.168.0.2
Destination: 108.177.119.94
[Source GeoIP: Unknown]
[Destination GeoIP: United States, AS15169 Google Inc., Mountain View, CA, 37.419201, -122.057404]
[Destination GeoIP Country: United States]
[Destination GeoIP AS Number: AS15169 Google Inc.]
[Destination GeoIP City: Mountain View, CA]
[Destination GeoIP Latitude: 37.419201]
[Destination GeoIP Longitude: -122.057404]
Internet Control Message Protocol
Type: 8 (Echo (ping) request)
Code: 0
Checksum: 0xd64a [correct]
[Checksum Status: Good]
Identifier (BE): 63814 (0xf946)
Identifier (LE): 18169 (0x46f9)
Sequence number (BE): 0 (0x0000)
Sequence number (LE): 0 (0x0000)
Data (56 bytes)
0000 7c d9 ab 94 00 00 00 00 00 00 00 00 00 00 00 00 |...............
0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0030 00 00 00 00 00 00 00 00 ........
Data: 7cd9ab940000000000000000000000000000000000000000...
[Length: 56]
Para AC66U eu recebo:
$tshark -r ac66u-eth0-dst.pcap -V
Frame 1: 98 bytes on wire (784 bits), 98 bytes captured (784 bits)
Encapsulation type: Ethernet (1)
Arrival Time: May 5, 2018 09:07:16.655875000 EEST
[Time shift for this packet: 0.000000000 seconds]
Epoch Time: 1525500436.655875000 seconds
[Time delta from previous captured frame: 0.000000000 seconds]
[Time delta from previous displayed frame: 0.000000000 seconds]
[Time since reference or first frame: 0.000000000 seconds]
Frame Number: 1
Frame Length: 98 bytes (784 bits)
Capture Length: 98 bytes (784 bits)
[Frame is marked: False]
[Frame is ignored: False]
[Protocols in frame: eth:ethertype:ip:icmp:data]
Ethernet II, Src: AsustekC_cb:20:d0 (2c:56:dc:cb:20:d0), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Address: Broadcast (ff:ff:ff:ff:ff:ff)
.... ..1. .... .... .... .... = LG bit: Locally administered address (this is NOT the factory default)
.... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
Source: AsustekC_cb:20:d0 (2c:56:dc:cb:20:d0)
Address: AsustekC_cb:20:d0 (2c:56:dc:cb:20:d0)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
Internet Protocol Version 4, Src: 192.168.0.2, Dst: 108.177.119.94
0100 .... = Version: 4
.... 0101 = Header Length: 20 bytes (5)
Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
0000 00.. = Differentiated Services Codepoint: Default (0)
.... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
Total Length: 84
Identification: 0x0000 (0)
Flags: 0x02 (Don't Fragment)
0... .... = Reserved bit: Not set
.1.. .... = Don't fragment: Set
..0. .... = More fragments: Not set
Fragment offset: 0
Time to live: 64
Protocol: ICMP (1)
Header checksum: 0x95ef [validation disabled]
[Header checksum status: Unverified]
Source: 192.168.0.2
Destination: 108.177.119.94
[Source GeoIP: Unknown]
[Destination GeoIP: United States, AS15169 Google Inc., Mountain View, CA, 37.419201, -122.057404]
[Destination GeoIP Country: United States]
[Destination GeoIP AS Number: AS15169 Google Inc.]
[Destination GeoIP City: Mountain View, CA]
[Destination GeoIP Latitude: 37.419201]
[Destination GeoIP Longitude: -122.057404]
Internet Control Message Protocol
Type: 8 (Echo (ping) request)
Code: 0
Checksum: 0x638c [correct]
[Checksum Status: Good]
Identifier (BE): 27906 (0x6d02)
Identifier (LE): 621 (0x026d)
Sequence number (BE): 0 (0x0000)
Sequence number (LE): 0 (0x0000)
Data (56 bytes)
0000 de 6b 49 05 00 00 00 00 00 00 00 00 00 00 00 00 .kI.............
0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0030 00 00 00 00 00 00 00 00 ........
Data: de6b49050000000000000000000000000000000000000000...
[Length: 56]
Eu acho que a seção (para AC66U):
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
pode sinalizar um problema? Alguma pista sobre isso?