Linux下traceroute的安装和使用

一、工具介绍

traceroute是跟踪数据包到达网络主机所经过的路由工具。其原理为试图以最小的TTL发出探测包来跟踪数据包到达目标主机所经过的网关，然后监听一个来自网关ICMP的应答。发送数据包的大小默认为40个字节。本篇我们将详细学习traceroute的用法。

二、traceroute的安装

yum install -y traceroute

三、traceroute的使用

首先我们开启ubuntu虚拟机，并且确保其能上网。安装traceroute软件。执行命令"apt-get install traceroute"进行安装。
我们介绍traceroute软件的命令格式为 traceroute [参数选项] hostname，域名或 IP地址。

首先我们执行第一条命令为"traceroute www.sina.com",对新浪地址进行追踪。

此处我们对结果加以说明：

记录按序列号从1开始，每个纪录就是一跳，每跳表示一个网关，我们看到每行有三个时间，单位是 ms，其实就是-q的默认参数。探测数据包向每个网关发送三个数据包后，网关响应后返回的时间；如果您用 traceroute -q 4 www.sina.com ，表示向每个网关发送4个数据包。

有时我们traceroute 一台主机时，会看到有一些行是以星号表示的。出现这样的情况，可能是防火墙封掉了ICMP的返回信息，所以我们得不到什么相关的数据包返回数据。

有时我们在某一网关处延时比较长，有可能是某台网关比较阻塞，也可能是物理设备本身的原因。当然如果某台DNS出现问题时，不能解析主机名、域名时，也会有延时长的现象；您可以加-n 参数来避免DNS解析，以IP格式输出数据。
下一条命令，"traceroute -q 4 www.sina.com",表示每次向网关发送的探测数据包数量为4。
下一条命令，"traceroute -m 10 www.wangshihai.com",表示设置的跳转数量为10次。
下一条命令，"traceroute -n www.wangshihai.com",表示不显示主机名，只显示IP地址。
下一条命令，"traceroute -p 7778 www.wangshihai.com",表示我们探测包使用UDP端口设置7778。
下一条命令，"traceroute -r www.wangshihai.com",表示绕过真正的路由，直接发送到网络主机。
下一条命令，"traceroute -w 5 www.wangshihai.com",表示我么设置对外发送探测包的等待响应时间设置为5秒。
下一条命令，我们可以路由追踪的时候指定使用设备的那个网口，以及使用IPV4或者IPV6 协议。本篇我们使用命令"traceroute -i eth0 -4 www.wangshihai.com"，表示使用eth0网口以及IPV4协议。

SYNOPSIS
       traceroute [-46dFITUnreAV] [-f first_ttl] [-g gate,...]
               [-i device] [-m max_ttl] [-p port] [-s src_addr]
               [-q nqueries] [-N squeries] [-t tos]
               [-l flow_label] [-w waittime] [-z sendwait] [-UL] [-D]
               [-P proto] [--sport=port] [-M method] [-O mod_options]
               [--mtu] [--back]
               host [packet_len]
       traceroute6  [options]

Options:
  -4                          Use IPv4
  -6                          Use IPv6
  -d  --debug                 Enable socket level debugging
  -F  --dont-fragment         Do not fragment packets
  -f first_ttl  --first=first_ttl
                              Start from the first_ttl hop (instead from 1)
  -g gate,...  --gateway=gate,...
                              Route packets through the specified gateway
                              (maximum 8 for IPv4 and 127 for IPv6)
  -I  --icmp                  Use ICMP ECHO for tracerouting
  -T  --tcp                   Use TCP SYN for tracerouting (default port is 80)
  -i device  --interface=device
                              Specify a network interface to operate with
  -m max_ttl  --max-hops=max_ttl
                              Set the max number of hops (max TTL to be
                              reached). Default is 30
  -N squeries  --sim-queries=squeries
                              Set the number of probes to be tried
                              simultaneously (default is 16)
  -n                          Do not resolve IP addresses to their domain names
  -p port  --port=port        Set the destination port to use. It is either
                              initial udp port value for "default" method
                              (incremented by each probe, default is 33434), or
                              initial seq for "icmp" (incremented as well,
                              default from 1), or some constant destination
                              port for other methods (with default of 80 for
                              "tcp", 53 for "udp", etc.)
  -t tos  --tos=tos           Set the TOS (IPv4 type of service) or TC (IPv6
                              traffic class) value for outgoing packets
  -l flow_label  --flowlabel=flow_label
                              Use specified flow_label for IPv6 packets
  -w waittime  --wait=waittime
                              Set the number of seconds to wait for response to
                              a probe (default is 5.0). Non-integer (float
                              point) values allowed too
  -q nqueries  --queries=nqueries
                              Set the number of probes per each hop. Default is
                              3
  -r                          Bypass the normal routing and send directly to a
                              host on an attached network
  -s src_addr  --source=src_addr
                              Use source src_addr for outgoing packets
  -z sendwait  --sendwait=sendwait
                              Minimal time interval between probes (default 0).
                              If the value is more than 10, then it specifies a
                              number in milliseconds, else it is a number of
                              seconds (float point values allowed too)
  -e  --extensions            Show ICMP extensions (if present), including MPLS
  -A  --as-path-lookups       Perform AS path lookups in routing registries and
                              print results directly after the corresponding
                              addresses
  -M name  --module=name      Use specified module (either builtin or external)
                              for traceroute operations. Most methods have
                              their shortcuts (`-I' means `-M icmp' etc.)
  -O OPTS,...  --options=OPTS,...
                              Use module-specific option OPTS for the
                              traceroute module. Several OPTS allowed,
                              separated by comma. If OPTS is "help", print info
                              about available options
  --sport=num                 Use source port num for outgoing packets. Implies
                              `-N 1'
  --fwmark=num                Set firewall mark for outgoing packets
  -U  --udp                   Use UDP to particular port for tracerouting
                              (instead of increasing the port per each probe),
                              default port is 53
  -UL                         Use UDPLITE for tracerouting (default dest port
                              is 53)
  -D  --dccp                  Use DCCP Request for tracerouting (default port
                              is 33434)
  -P prot  --protocol=prot    Use raw packet of protocol prot for tracerouting
  --mtu                       Discover MTU along the path being traced. Implies
                              `-F -N 1'
  --back                      Guess the number of hops in the backward path and
                              print if it differs
  -V  --version               Print version info and exit
  --help                      Read this help and exit
Arguments:
+     host          The host to traceroute to
      packetlen     The full packet length (default is the length of an IP
                    header plus 40). Can be ignored or increased to a minimal
                    allowed value