使用Python方法

比用各种命令方便，可以设置超时时间，到底通不通，端口是否开放一眼能看出来。

命令和返回

完整权限，可以ping通，端口开放，结果如下：

无root权限（省略了ping），端口开放，结果如下：

完整权限，可以ping通，远端端口关闭，结果如下：

完整权限，可以ping通，本地端口关闭，结果如下：

完整权限，不能ping通（端口自然也无法访问），结果如下：

pnp.py代码

#!/usr/bin/python
#name pnp.py
#ping and port
#coding:utf-8

import os, sys, socket, struct, select, time
ICMP_ECHO_REQUEST = 8 # Seems to be the same on Solaris.
socket.setdefaulttimeout(4)

#first argument
host=sys.argv[1]

#second argument
port=int(sys.argv[2])

#socket try connect

def PortOpen(ip,port):
    print( '\033[1m*Port\033[0m %s:%d' %(ip,port)),
    s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)

    try:
        s.connect((ip,port))
        s.shutdown(2)
        print( '\033[1;32m.... is OK.\033[0m' ) 
        return True

    except socket.timeout:
        print( '\033[1;33m.... is down or network time out!!!\033[0m' ) 
        return False
        			
    except:

        print( '\033[1;31m.... is down!!!\033[0m' ) 
        return False

def checksum(source_string):
  """
  I'm not too confident that this is right but testing seems
  to suggest that it gives the same answers as in_cksum in ping.c
  """
  sum = 0
  countTo = (len(source_string)/2)*2
  count = 0
  while count<countTo:
    thisVal = ord(source_string[count + 1])*256 + ord(source_string[count])
    sum = sum + thisVal
    sum = sum & 0xffffffff # Necessary?
    count = count + 2
  if countTo<len(source_string):
    sum = sum + ord(source_string[len(source_string) - 1])
    sum = sum & 0xffffffff # Necessary?
  sum = (sum >> 16) + (sum & 0xffff)
  sum = sum + (sum >> 16)
  answer = ~sum
  answer = answer & 0xffff
  # Swap bytes. Bugger me if I know why.
  answer = answer >> 8 | (answer << 8 & 0xff00)
  return answer
def receive_one_ping(my_socket, ID, timeout):
  """
  receive the ping from the socket.
  """
  timeLeft = timeout
  while True:
    startedSelect = time.time()
    whatReady = select.select([my_socket], [], [], timeLeft)
    howLongInSelect = (time.time() - startedSelect)
    if whatReady[0] == []: # Timeout
      return
    timeReceived = time.time()
    recPacket, addr = my_socket.recvfrom(1024)
    icmpHeader = recPacket[20:28]
    type, code, checksum, packetID, sequence = struct.unpack(
      "bbHHh", icmpHeader
    )
    if packetID == ID:
      bytesInDouble = struct.calcsize("d")
      timeSent = struct.unpack("d", recPacket[28:28 + bytesInDouble])[0]
      return timeReceived - timeSent
    timeLeft = timeLeft - howLongInSelect
    if timeLeft <= 0:
      return
def send_one_ping(my_socket, dest_addr, ID):
  """
  Send one ping to the given >dest_addr<.
  """
  dest_addr = socket.gethostbyname(dest_addr)
  # Header is type (8), code (8), checksum (16), id (16), sequence (16)
  my_checksum = 0
  # Make a dummy heder with a 0 checksum.
  header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, my_checksum, ID, 1) 
  #a1 = struct.unpack("bbHHh",header)  #my test
  bytesInDouble = struct.calcsize("d")
  data = (192 - bytesInDouble) * "Q"
  data = struct.pack("d", time.time()) + data
  # Calculate the checksum on the data and the dummy header.
  my_checksum = checksum(header + data)
  # Now that we have the right checksum, we put that in. It's just easier
  # to make up a new header than to stuff it into the dummy.
  header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, socket.htons(my_checksum), ID, 1)
  packet = header + data
  my_socket.sendto(packet, (dest_addr, 1)) # Don't know about the 1
def do_one(dest_addr, timeout):
  """
  Returns either the delay (in seconds) or none on timeout.
  """
  delay=None
  icmp = socket.getprotobyname("icmp")
  try:
    my_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
    my_ID = os.getpid() & 0xFFFF
    send_one_ping(my_socket, dest_addr, my_ID)
    delay = receive_one_ping(my_socket, my_ID, timeout)
    my_socket.close()
  except socket.error, (errno, msg):
    if errno == 1:
      # Operation not permitted
      msg = msg + (
        " - not root."
      )
      raise socket.error(msg)
    #raise # raise the original error
  return delay
def verbose_ping(dest_addr, timeout = 2, count = 100):
  """
  Send >count< ping to >dest_addr< with the given >timeout< and display
  the result.
  """
  for i in xrange(count):
    print "\033[1m*Ping\033[0m %s ..." % dest_addr,
    try:
      delay = do_one(dest_addr, timeout)
    except socket.error, e:
      print "\033[1;31m... failed. (%s)" % e
      break
    if delay == None:
      print "\033[1;31m... failed. (timeout within %ssec.)\033[0m" % timeout
    else:
      delay = delay * 1000
      print "\033[1;32m... get ping in %0.4fms\033[0m" % delay

if __name__ == '__main__':
  if os.geteuid() == 0:
    verbose_ping(host,2,3)
  else:
  	print "\033[1m*Ping\033[0m test must be sudo or root..."
  PortOpen(host,port)
  print( 'Job finished.')

使用命令方法

使用命令ping就不说了，端口可以用下面的命令。
当时目前telnet基本不用，可能没有telnet客户端了。
测试通常连接不上会等很久，端口连上了也需要通过反馈内容自行判断。

telnet

telnet ip port

$telnet 192.168.234.1
Trying 192.168.234.1...
Connected to 192.168.234.1.
Escape character is '^]'.
......

wget

wget ip:port

$wget 192.168.234.1:21
--2019-03-22 15:42:27--  http://192.168.234.1:21/
正在连接 192.168.234.1:21... 已连接。
已发出 HTTP 请求，正在等待回应... 200 没有 HTTP 头，尝试 HTTP/0.9
长度：未指定
正在保存至: “index.html”
......

SSH

ssh -v ip -p port

$ssh -v 192.168.234.1 -p 21
OpenSSH_7.4p1, OpenSSL 1.0.2k-fips  26 Jan 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 58: Applying options for *
debug1: Connecting to 192.168.234.1 [192.168.234.1] port 21.
debug1: Connection established.
......

curl

culr ip:port

$curl 192.168.234.1:21
220 Serv-U FTP Server v15.1 ready...
530 Not logged in.
......