为什么我可以ping一个服务器却不能通过SSH连接?

When I ping my server, it responds:

当我ping服务器时，它会响应:

user@localhost:~$ ping my.server
PING my.server (111.111.111.11) 56(84) bytes of data.
64 bytes from my.server (111.111.111.11): icmp_req=1 ttl=42 time=38.4 ms
64 bytes from my.server (111.111.111.11): icmp_req=2 ttl=42 time=50.0 ms
64 bytes from my.server (111.111.111.11): icmp_req=3 ttl=42 time=58.6 ms
^C
--- my.server ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 38.419/49.037/58.637/8.287 ms

but when I try to ssh (something that I always do, and have been doing for the past few hours on the same connection), it hangs:

但是，当我尝试ssh(我总是这样做，并且在过去的几个小时内一直在做相同的连接)时，它挂起了:

user@localhost:~$ ssh my.server

http://speedtest.net says that my connection has 1.5 Mbps download and 0.4 Mbps upload speed.

http://speedtest.net说我的连接有1.5 Mbps下载和0.4 Mbps上传速度。

Is there a reason that ssh hangs?

为什么有ssh挂起?

Results from suggestions provided in answers

根据答案提供的建议结果。

from @nsfyn55

从@nsfyn55

user@localhost:~$ telnetmy.server 22 
Trying 111.111.111.11...
Connected to my.server
Escape character is '^]'.
SSH-2.0-OpenSSH_4.3
Connection closed by foreign host.

from @vahid:

从@vahid:

user@localhost:~$ nc -v -w 1 111.111.111.111 -z 22
nc: timeout cannot be negative

3 个解决方案

#1

ping (ICMP protocol) and ssh are two different protocols.

ping (ICMP协议)和ssh是两种不同的协议。

It could be that ssh service is not running or not installed

可能是ssh服务没有运行或没有安装。
firewall restriction (local to server like iptables or even sshd config lock down ) or (external firewall that protects incomming traffic to network hosting 111.111.111.111)

防火墙限制(本地到服务器，如iptables，甚至是sshd配置锁定)或(保护incomming流量的外部防火墙，以网络托管111.111.111.111)

First check is to see if ssh port is up

首先检查ssh端口是否向上。

nc -v -w 1 111.111.111.111 -z 22

if it succeeds then ssh should communicate if not then it will never work until restriction is lifted or ssh is started

如果它成功，那么ssh应该通信，否则它将永远不会工作，直到限制解除或ssh启动。

#2

Find out two pieces of information

找出两条信息。

Whats the hostname or IP of the target ssh sever
目标ssh服务器的主机名或IP是什么。
What port is the ssh daemon listening on (default is port 22)
什么端口是ssh守护进程监听(默认是端口22)

$> telnet <hostname or ip> <port>

$> telnet <主机名或ip> <端口> 。

Assuming the daemon is up and running and listening on that port it should etablish a telnet session. Likely causes:

假设守护进程已经启动并在该端口上运行和侦听，它应该etablish一个telnet会话。可能的原因:

The ssh daemon is not running
ssh守护进程没有运行。
The host is blocking the target port with its software firewall
主机通过其软件防火墙阻止目标端口。
Some intermediate network device is blocking or filtering the target port
一些中间网络设备阻塞或过滤目标端口。
The ssh daemon is listening on a non standard port
ssh守护进程正在监听非标准端口。
A TCP wrapper is configured and is filtering out your source host
配置TCP包装器并过滤掉源主机。

#3

-2

On the server, try:

在服务器上,试题:

netstat -an

and look to see if tcp port 22 is opened (use findstr in Windows or grep in Unix).

查看tcp端口22是否被打开(在Windows中使用findstr或在Unix中使用grep)。

#1