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AdrienF's questions

Martin Hope
AdrienF
Asked: 2020-06-10 00:03:12 +0800 CST
  • 15

Por algum motivo, não consigo acessar github.com, a conexão simplesmente expira; Eu tenho tido esse problema consistentemente nos últimos dias. Não tenho esse problema com nenhum outro site.

Estou executando o macOS 10.15.5. Em execução traceroute, vejo que o DNS é resolvido, mas depois se perde ( edit : as respostas apontaram que isso é esperado para o github):

$ traceroute github.com
traceroute to github.com (192.30.253.113), 64 hops max, 72 byte packets
 1  10.0.0.1 (10.0.0.1)  5.508 ms  1.134 ms  1.275 ms
 2  192.168.1.1 (192.168.1.1)  3.066 ms  2.711 ms  2.658 ms
 3  80.10.124.196 (80.10.124.196)  69.645 ms  53.357 ms  55.386 ms
 4  10.125.222.74 (10.125.222.74)  54.702 ms  61.938 ms  38.273 ms
 5  ae44-0.niidf202.paris15earrondissement.francetelecom.net (193.252.98.246)  108.873 ms  32.476 ms  102.200 ms
 6  193.252.137.74 (193.252.137.74)  55.651 ms  82.649 ms  70.433 ms
 7  zayo-9.gw.opentransit.net (193.251.250.188)  38.020 ms  85.435 ms  91.153 ms
 8  ae27.cs1.cdg11.fr.eth.zayo.com (64.125.29.4)  168.142 ms  220.846 ms  195.284 ms
 9  ae0.cs1.cdg12.fr.eth.zayo.com (64.125.29.84)  180.439 ms  119.870 ms  108.460 ms
10  ae2.cs3.lhr11.uk.eth.zayo.com (64.125.29.25)  114.051 ms * *
11  * * *
12  * * *
13  * * *
14  209.66.120.181.ipyx-243981-004-zyo.zip.zayo.com (209.66.120.181)  112.761 ms  120.212 ms  113.661 ms
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
...

Usar hostconfirma que o DNS resolve

$ host github.com
github.com has address 140.82.113.4
github.com mail is handled by 5 ALT1.ASPMX.L.GOOGLE.com.
github.com mail is handled by 5 ALT2.ASPMX.L.GOOGLE.com.
github.com mail is handled by 10 ALT3.ASPMX.L.GOOGLE.com.
github.com mail is handled by 10 ALT4.ASPMX.L.GOOGLE.com.
github.com mail is handled by 1 ASPMX.L.GOOGLE.com.

Executando curl no IP de host, posso ver o tempo limite da conexão tentando alcançar 192.30.253.113:

$ curl -v --insecure -L 140.82.113.4

*   Trying 140.82.113.4...
* TCP_NODELAY set
* Connected to 140.82.113.4 (140.82.113.4) port 80 (#0)
> GET / HTTP/1.1
> Host: 140.82.113.4
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 301 Moved Permanently
< Content-length: 0
< Location: https://140.82.113.4/
<
* Connection #0 to host 140.82.113.4 left intact
* Issue another request to this URL: 'https://140.82.113.4/'
*   Trying 140.82.113.4...
* TCP_NODELAY set
* Connected to 140.82.113.4 (140.82.113.4) port 443 (#1)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/cert.pem
  CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256
* ALPN, server accepted to use http/1.1
* Server certificate:
*  subject: C=US; ST=California; L=San Francisco; O=GitHub, Inc.; CN=github.com
*  start date: May  5 00:00:00 2020 GMT
*  expire date: May 10 12:00:00 2022 GMT
*  issuer: C=US; O=DigiCert Inc; OU=www.digicert.com; CN=DigiCert SHA2 High Assurance Server CA
*  SSL certificate verify ok.
> GET / HTTP/1.1
> Host: 140.82.113.4
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 301 Moved Permanently
< Content-length: 0
< Location: https://github.com/
<
* Connection #1 to host 140.82.113.4 left intact
* Issue another request to this URL: 'https://github.com/'
*   Trying 192.30.253.113...
* TCP_NODELAY set
* Connection failed
* connect to 192.30.253.113 port 443 failed: Operation timed out
* Failed to connect to github.com port 443: Operation timed out
* Closing connection 2
curl: (7) Failed to connect to github.com port 443: Operation timed out
* Closing connection 0
* Closing connection 1

Neste ponto, acho que o problema está do lado do github, mas sou o único com esse problema entre todos os meus colegas.

Editar 2 Fiz login com a conta de convidado do macOS e consegui acessar o github. O problema ainda aparece em outra conta de usuário comum. Portanto, o problema vem de alguma configuração específica do usuário.

Eu também corri sudo killall -HUP mDNSRespondere sudo dscacheutil -flushcache; não resolveu o problema.

Editar 3 Se eu chamar curlsem -L(ou seja, sem redirecionamentos) a solicitação for bem-sucedida, recebo o HTML para o GitHub de volta:

$ curl -H "Host: github.com" --insecure -v https://140.82.118.3/
*   Trying 140.82.118.3...
* TCP_NODELAY set
* Connected to 140.82.118.3 (140.82.118.3) port 443 (#0)
[...]
* TLSv1.2 (IN), TLS handshake, Finished (20):
[...]
<!DOCTYPE html>
<html lang="en">
  <head>
[...]
routing