我刚搬到一间新公寓，并通过路由器与Internet连接，但发现无法连接到许多使用SSL的站点。
例如，尝试连接到贝宝：
curl -v https://paypal.com
* About to connect() to paypal.com port 443 (#0)
* Trying 66.211.169.3... connected
* successfully set certificate verify locations:
* CAfile: none
CApath: /etc/ssl/certs
* SSLv3, TLS handshake, Client hello (1):
* Unknown SSL protocol error in connection to paypal.com:443
* Closing connection #0
curl: (35) Unknown SSL protocol error in connection to paypal.com:443
curl -v -ssl https://paypal.com 给出相同的输出。
对于某些网站，它可以工作：
curl -v https://www.google.com
* About to connect() to www.google.com port 443 (#0)
* Trying 74.125.235.112... connected
* successfully set certificate verify locations:
* CAfile: none
CApath: /etc/ssl/certs
* SSLv3, TLS handshake, Client hello (1):
* SSLv3, TLS handshake, Server hello (2):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS handshake, Server key exchange (12):
* SSLv3, TLS handshake, Server finished (14):
* SSLv3, TLS handshake, Client key exchange (16):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSL connection using ECDHE-RSA-RC4-SHA
* Server certificate:
* subject: C=US; ST=California; L=Mountain View; O=Google Inc; CN=www.google.com
* start date: 2011-10-26 00:00:00 GMT
* expire date: 2013-09-30 23:59:59 GMT
* common name: www.google.com (matched)
* issuer: C=ZA; O=Thawte Consulting (Pty) Ltd.; CN=Thawte SGC CA
* SSL certificate verify ok.
> GET / HTTP/1.1
> User-Agent: curl/7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/1.2.3.4 libidn/1.23 librtmp/2.3
> Host: www.google.com
> Accept: */*
>
< HTTP/1.1 302 Found
< Location: https://www.google.co.jp/
.
.
.
我使用的是Ubuntu 12.04，同时也安装了Windows 7。这些站点可在Windows上运行：(
不知道这些信息是否有帮助，但是我跑ifconfig了下来并得到以下信息：
eth0 Link encap:Ethernet HWaddr 1c:c1:de:bc:e2:4f
inet6 addr: 2408:c3:7fff:991:686b:8d18:81b3:8dd1/64 Scope:Global
inet6 addr: 2408:c3:7fff:991:1ec1:deff:febc:e24f/64 Scope:Global
inet6 addr: fe80::1ec1:deff:febc:e24f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:87075 errors:0 dropped:0 overruns:0 frame:0
TX packets:54522 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:78167937 (78.1 MB) TX bytes:10016891 (10.0 MB)
Interrupt:46 Base address:0x4000
eth1 Link encap:Ethernet HWaddr ac:81:12:0d:93:80
inet6 addr: fe80::ae81:12ff:fe0d:9380/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:498
TX packets:0 errors:26 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:17
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:630 errors:0 dropped:0 overruns:0 frame:0
TX packets:630 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:39592 (39.5 KB) TX bytes:39592 (39.5 KB)
ppp0 Link encap:Point-to-Point Protocol
inet addr:180.57.228.200 P-t-P:118.23.8.175 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1
RX packets:39631 errors:0 dropped:0 overruns:0 frame:0
TX packets:22391 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:43462054 (43.4 MB) TX bytes:2834628 (2.8 MB)
我已经运行了PING：
ping www.paypal.com
PING e6166.b.akamaiedge.net (184.31.66.234) 56(84) bytes of data.
64 bytes from a184-31-66-234.deploy.akamaitechnologies.com (184.31.66.234): icmp_req=1 ttl=54 time=15.3 ms
64 bytes from a184-31-66-234.deploy.akamaitechnologies.com (184.31.66.234): icmp_req=2 ttl=54 time=15.0 ms
64 bytes from a184-31-66-234.deploy.akamaitechnologies.com (184.31.66.234): icmp_req=3 ttl=54 time=15.2 ms
64 bytes from a184-31-66-234.deploy.akamaitechnologies.com (184.31.66.234): icmp_req=4 ttl=54 time=17.2 ms
64 bytes from a184-31-66-234.deploy.akamaitechnologies.com (184.31.66.234): icmp_req=5 ttl=54 time=16.6 ms
64 bytes from a184-31-66-234.deploy.akamaitechnologies.com (184.31.66.234): icmp_req=6 ttl=54 time=16.7 ms
64 bytes from a184-31-66-234.deploy.akamaitechnologies.com (184.31.66.234): icmp_req=7 ttl=54 time=14.8 ms
^C
--- e6166.b.akamaiedge.net ping statistics ---
7 packets transmitted, 7 received, 0% packet loss, time 6009ms
rtt min/avg/max/mdev = 14.878/15.890/17.214/0.901 ms
如果没有www：
ping paypal.com
PING paypal.com (66.211.169.66) 56(84) bytes of data.
^C
--- paypal.com ping statistics ---
303 packets transmitted, 0 received, 100% packet loss, time 302265ms
追踪者：
traceroute www.paypal.com
traceroute to www.paypal.com (184.31.66.234), 30 hops max, 60 byte packets
1 118.23.8.175 (118.23.8.175) 8.424 ms 8.404 ms 8.540 ms
2 118.23.10.121 (118.23.10.121) 8.212 ms 8.189 ms 8.162 ms
3 122.1.164.213 (122.1.164.213) 9.405 ms 11.359 ms 13.469 ms
4 60.37.55.165 (60.37.55.165) 8.049 ms 8.072 ms 8.040 ms
5 118.23.168.89 (118.23.168.89) 8.574 ms 8.549 ms 8.558 ms
6 210.163.230.238 (210.163.230.238) 8.667 ms 7.605 ms 7.545 ms
7 xe-4-0-0.a21.osakjp01.jp.ra.gin.ntt.net (61.213.169.218) 18.255 ms 18.232 ms xe-3-0-0.a21.osakjp01.jp.ra.gin.ntt.net (61.213.162.206) 19.042 ms
8 * * *
9 * * *
.
.
.
29 * * *
30 * * *
没有www：
traceroute paypal.com
traceroute to paypal.com (66.211.169.66), 30 hops max, 60 byte packets
1 118.23.8.175 (118.23.8.175) 5.607 ms 5.674 ms 5.875 ms
2 118.23.10.121 (118.23.10.121) 5.468 ms 5.453 ms 5.576 ms
3 122.1.164.213 (122.1.164.213) 7.595 ms 10.062 ms 11.660 ms
4 60.37.55.165 (60.37.55.165) 5.684 ms 5.660 ms 5.635 ms
5 60.37.27.90 (60.37.27.90) 5.960 ms 5.924 ms 5.898 ms
6 ae-11.r20.tokyjp01.jp.bb.gin.ntt.net (129.250.12.197) 86.468 ms 30.960 ms 30.899 ms
7 as-1.r20.sttlwa01.us.bb.gin.ntt.net (129.250.4.189) 161.185 ms 144.343 ms 132.410 ms
8 ae-1.r05.sttlwa01.us.bb.gin.ntt.net (129.250.5.47) 139.008 ms 127.377 ms 139.050 ms
9 xe-0.sprint.sttlwa01.us.bb.gin.ntt.net (129.250.9.190) 116.006 ms 104.306 ms 115.954 ms
10 144.232.1.153 (144.232.1.153) 141.046 ms 129.870 ms 140.991 ms
11 sl-crs2-sj-0-5-2-0.sprintlink.net (144.232.18.204) 131.271 ms 131.248 ms 142.544 ms
12 sl-st31-sj-0-15-0-0.sprintlink.net (144.232.8.151) 129.543 ms 141.575 ms 141.066 ms
13 * * *
14 * * *
.
.
.
29 * * *
30 * * *
tcpdump：
1 0.000000 114.178.88.59 66.211.169.66 TCP 76 37374 > https [SYN] Seq=0 Win=14520 Len=0 MSS=1452 SACK_PERM=1 TSval=68855 TSecr=0 WS=64
2 0.136291 66.211.169.66 114.178.88.59 TCP 80 https > 37374 [SYN, ACK] Seq=0 Ack=1 Win=4356 Len=0 MSS=1460 WS=1 TSval=3608913175 TSecr=68855 SACK_PERM=1
3 0.136322 114.178.88.59 66.211.169.66 TCP 68 37374 > https [ACK] Seq=1 Ack=1 Win=14528 Len=0 TSval=68889 TSecr=3608913175
4 0.137409 114.178.88.59 66.211.169.66 SSL 309 Client Hello
5 0.274446 66.211.169.66 114.178.88.59 SSL 95 [TCP Previous segment lost] Continuation Data
6 0.274469 114.178.88.59 66.211.169.66 TCP 80 [TCP Dup ACK 4#1] 37374 > https [ACK] Seq=242 Ack=1 Win=14528 Len=0 TSval=68923 TSecr=3608913175 SLE=2881 SRE=2908
7 7.117833 91.189.89.76 114.178.88.59 TLSv1 142 Application Data, Application Data
8 7.118823 114.178.88.59 91.189.89.76 TLSv1 216 Application Data, Application Data, Application Data, Application Data
9 7.393725 91.189.89.76 114.178.88.59 TCP 68 https > 41264 [ACK] Seq=75 Ack=149 Win=146 Len=0 TSval=875420654 TSecr=70634
10 60.301444 66.211.169.66 114.178.88.59 TCP 56 https > 37374 [RST, ACK] Seq=2908 Ack=242 Win=4597 Len=0
这是日本的ISP，即使我要通过电缆连接到调制解调器/路由器，也需要添加用户名和密码，但是在Ubuntu的“有线”连接中，我无法添加这些用户名和密码。我的室友告诉我创建一个OCN连接，但是我不确定这是网络类型的名称还是日本公司的名称...但是在查看她的计算机后，我们发现它是PPPoE连接。经过一番谷歌搜索后，我了解到要创建PPPoE连接，我需要创建DSL连接，并且可以为其添加密码和用户名。我还将“有线”连接更改为不自动连接。
如果直接连接调制解调器，也会遇到同样的问题。
我曾尝试将DSL MTU更改为500、1500、1492和1482，但这并没有改变。
同样由于某种原因，Ubuntu并不总是能够建立连接，有时我必须重新启动才能连接。
感谢您的所有帮助，问题终于得到解决！
我试图限制MTU以查看是否有帮助，并最终使用它pppoeconf来建立PPPoE连接，因为它限制了我的MTU。然后，我禁用了以前使用的DSL连接。
对于遇到类似问题的任何人，您都可以通过键入sudo ppoeconf并按照说明尝试该解决方案。然后，您可以连接pon adsl-provider和断开连接poff
本文收集自互联网，转载请注明来源。
如有侵权，请联系[email protected] 删除。
我来说两句