route 中文man页面-route的中文

NAME

route - 显示 / 操作IP选路表

总览 SYNOPSIS

route [-CFvnee]

route [-v] [-A family] add [-net|-host] target [netmask Nm] [gw Gw] [metric N] [mss M] [window W] [irtt I][reject] [mod] [dyn] [reinstate] [[dev] If]

route [-v] [-A family] del [-net|-host] target [gw Gw][netmask Nm] [metric N] [[dev] If]

route [-V] [--version] [-h] [--help]

描述 DESCRIPTION

route程序对内核的IP选路表进行操作。它主要用于通过已用ifconfig(8)程序配置好的接口来指定的主机或网络设置静态路由。

选项 OPTIONS

-v: 选用细节操作模式
-A family: 用指定的地址族(如`inet'，`inet6')。
-n: 以数字形式代替解释主机名形式来显示地址。此项对试图检测对域名服务器进行路由发生故障的原因非常有用。
-e: 用netstat(8)的格式来显示选路表。-ee将产生包括选路表所有参数在内的大量信息。
-net: 路由目标为网络。
-host: 路由目标为主机。
-F: 显示内核的FIB选路表。其格式可以用-e 和 -ee选项改变。
-C: 显示内核的路由缓存。
del: 删除一条路由。
add: 添加一条路由。
target: 指定目标网络或主机。可以用点分十进制形式的IP地址或主机/网络名。
netmask Nm: 为添加的路由指定网络掩码。
gw Gw: 为发往目标网络/主机的任何分组指定网关。注意：指定的网关首先必须是可达的。也就是说必须为该网关预先指定一条静态路由。如果你为本地接口之一指定这个网关地址的话，那么此网关地址将用于决定此接口上的分组将如何进行路由。这是BSD风格所兼容的。
metric M: 把选路表中的路由值字段(由选路进程使用)设为M。
mss M: 把基于此路由之上的连接的TCP***报文段长度设为M字节。这通常只用于优化选路设置。默认值为536。
window W: 把基于此路由之上的连接的TCP窗口长度设为W字节。这通常只用于AX.25网络和不能处理背对背形式的帧的设备。
irtt I: 把基于此路由之上的TCP连接的初始往返时间设为I毫秒(1-12000)。这通常也只用于AX.25网络。如果省略此选项，则使用RFC1122的缺省值300ms。
reject: 设置一条阻塞路由以使一条路由查找失败。这用于在使用缺省路由前先屏蔽掉一些网络。但这并不起到防火墙的作用。
mod, dyn, reinstate: 设置一条动态的或更改过的路由。这些标志通常只由选路进程来设置。这只用于诊断目的，
dev If: 强制使路由与指定的设备关联，因为否则内核会自己来试图检测相应的设备(通常检查已存在的路由和加入路由的设备的规格)。在多数正常的网络上无需使用。
如果dev If是命令行上***一个指定的选项，那么可以省略关键字dev，因为它是缺省值。否则路由修改对象(metric - netmask- gw - dev)无关紧要。

范例 EXAMPLES

route add -net 127.0.0.0: 加入正常的环回接口项，它使用掩码255.0.0.0(由目标地址决定了它是A类网络)并与设备"lo"相关联(假定该设备先前已由ifconfig(8)正确设置)。
route add -net 192.56.76.0 netmask 255.255.255.0 dev eth0: 向"eth0"添加一条指向网络192.56.76.x的路由。其中的C类子网掩码并不必须，因为192.*是个C类的IP地址。在此关键字"dev"可省略。
route add default gw mango-gw: 加入一条缺省路由(如果无法匹配其它路由则用它)。使用此路由的所有分组将通过网关"mango-gw"进行传输。实际使用此路由的设备取决于如何到达"mango-gw" - 先前必须设好到"mango-gw"的静态路由。
route add ipx4 sl0: 向SLIP接口添加一条指向"ipx4"的路由(假定"ipx4"是使用SLIP的主机)。
route add -net 192.57.66.0 netmask 255.255.255.0 gw ipx4: 此命令为先前SLIP接口的网关ipx4添加到网络"192.57.66.x"的路由。
route add 224.0.0.0 netmask 240.0.0.0 dev eth0: 此命令为"eth0"设定所有D类地址(用于组播)的路由。这是用于组播内核的正确配置行。
route add 10.0.0.0 netmask 255.0.0.0 reject: 此命令为私有网络"10.x.x.x."设置一条阻塞路由。

输出信息 OUTPUT

内核选路表的输出信息由以下栏目组成：

Destination: 目标网络或目标主机。
Gateway: 网关地址或'*'(如未设)。
Genmask: 目标网络的子网掩码；'255.255.255.255'为主机，'0.0.0.0'为缺省路由。
Flags: 可能出现的标志有：
U (route is up) 路由正常
H (target is a host) 主机路由
G (use gateway) 使用网关的间接路由
R (reinstate route for dynamic routing) 为动态选路恢复路由
D (dynamically installed by daemon or redirect) 该路由由选路进程或重定向动态创建
M (modified from routing daemon or rederict) 该路由已由选路进程或重定向修改
! (reject route) 阻塞路由
Metric: 通向目标的距离(通常以跳来计算)。新内核不使用此概念，而选路进程可能会用。
Ref: 使用此路由的活动进程个数(Linux内核并不使用)。
Use: 查找此路由的次数。根据-F 和 -C的使用，此数值是路由缓存的损失数或采样数。
Iface: 使用此路由发送分组的接口。
MSS: 基于此路由的TCP连接的缺省***报文段长度。
Window: 基于此路由的TCP连接的缺省窗口长度。
irtt: 初始往返时间。内核用它来猜测***TCP协议参数而无须等待(可能很慢的)应答。
HH (cached only): 为缓存过的路由而访问硬件报头缓存的ARP记录和缓存路由的数量。如果缓存过路由的接口(如lo)无须硬件地址则值为-1。
Arp (cached only): 无论缓存路由所用的硬件地址情况如何都进行更新。

文件 FILES

/proc/net/ipv6_route
/proc/net/route
/proc/net/rt_cache

参见SEE ALSO

ifconfig(8), netstat(8), arp(8), rarp(8)

#p#

NAME

route - show / manipulate the IP routing table

SYNOPSIS

route [-CFvnee]

route: [-v] [-A family] add [-net|-host] target [netmask Nm] [gw Gw] [metric N] [mss M] [window W] [irtt I] [reject] [mod] [dyn] [reinstate] [[dev] If]
route: [-v] [-A family] del [-net|-host] target [gw Gw] [netmask Nm] [metric N] [[dev] If]
route: [-V] [--version] [-h] [--help]

DESCRIPTION

Route manipulates the kernel's IP routing tables. Its primary use is to set up static routes to specific hosts or networks via an interface after it has been configured with the ifconfig(8) program.

When the add or del options are used, route modifies the routing tables. Without these options, route displays the current contents of the routing tables.

OPTIONS

-A family: use the specified address family (eg `inet'; use `route --help' for a full list).
-F: operate on the kernel's FIB (Forwarding Information Base) routing table. This is the default.
-C: operate on the kernel's routing cache.
-v: select verbose operation.
-n: show numerical addresses instead of trying to determine symbolic host names. This is useful if you are trying to determine why the route to your nameserver has vanished.
-e: use netstat(8)-format for displaying the routing table. -ee will generate a very long line with all parameters from the routing table.
del: delete a route.
add: add a new route.
target: the destination network or host. You can provide IP addresses in dotted decimal or host/network names.
-net: the target is a network.
-host: the target is a host.
netmask NM: when adding a network route, the netmask to be used.
gw GW: route packets via a gateway. NOTE: The specified gateway must be reachable first. This usually means that you have to set up a static route to the gateway beforehand. If you specify the address of one of your local interfaces, it will be used to decide about the interface to which the packets should be routed to. This is a BSDism compatibility hack.
metric M: set the metric field in the routing table (used by routing daemons) to M.
mss M: set the TCP Maximum Segment Size (MSS) for connections over this route to M bytes. The default is the device MTU minus headers, or a lower MTU when path mtu discovery occured. This setting can be used to force smaller TCP packets on the other end when path mtu discovery does not work (usually because of misconfigured firewalls that block ICMP Fragmentation Needed)
window W: set the TCP window size for connections over this route to W bytes. This is typically only used on AX.25 networks and with drivers unable to handle back to back frames.
irtt I: set the initial round trip time (irtt) for TCP connections over this route to I milliseconds (1-12000). This is typically only used on AX.25 networks. If omitted the RFC 1122 default of 300ms is used.
reject: install a blocking route, which will force a route lookup to fail. This is for example used to mask out networks before using the default route. This is NOT for firewalling.
mod, dyn, reinstate: install a dynamic or modified route. These flags are for diagnostic purposes, and are generally only set by routing daemons.
dev If: force the route to be associated with the specified device, as the kernel will otherwise try to determine the device on its own (by checking already existing routes and device specifications, and where the route is added to). In most normal networks you won't need this.
If dev If is the last option on the command line, the word dev may be omitted, as it's the default. Otherwise the order of the route modifiers (metric - netmask - gw - dev) doesn't matter.

EXAMPLES

route add -net 127.0.0.0: adds the normal loopback entry, using netmask 255.0.0.0 (class A net, determined from the destination address) and associated with the "lo" device (assuming this device was prviously set up correctly with ifconfig(8)).
route add -net 192.56.76.0 netmask 255.255.255.0 dev eth0: adds a route to the network 192.56.76.x via "eth0". The Class C netmask modifier is not really necessary here because 192.* is a Class C IP address. The word "dev" can be omitted here.
route add default gw mango-gw: adds a default route (which will be used if no other route matches). All packets using this route will be gatewayed through "mango-gw". The device which will actually be used for that route depends on how we can reach "mango-gw" - the static route to "mango-gw" will have to be set up before.
route add ipx4 sl0: Adds the route to the "ipx4" host via the SLIP interface (assuming that "ipx4" is the SLIP host).
route add -net 192.57.66.0 netmask 255.255.255.0 gw ipx4: This command adds the net "192.57.66.x" to be gatewayed through the former route to the SLIP interface.
route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0: This is an obscure one documented so people know how to do it. This sets all of the class D (multicast) IP routes to go via "eth0". This is the correct normal configuration line with a multicasting kernel.
route add -net 10.0.0.0 netmask 255.0.0.0 reject: This installs a rejecting route for the private network "10.x.x.x."

OUTPUT

The output of the kernel routing table is organized in the following columns

Destination: The destination network or destination host.
Gateway: The gateway address or '*' if none set.
Genmask: The netmask for the destination net; '255.255.255.255' for a host destination and '0.0.0.0' for the default route.
Flags: Possible flags include
U (route is up)
H (target is a host)
G (use gateway)
R (reinstate route for dynamic routing)
D (dynamically installed by daemon or redirect)
M (modified from routing daemon or redirect)
A (installed by addrconf)
C (cache entry)
! (reject route)
Metric: The 'distance' to the target (usually counted in hops). It is not used by recent kernels, but may be needed by routing daemons.
Ref: Number of references to this route. (Not used in the Linux kernel.)
Use: Count of lookups for the route. Depending on the use of -F and -C this will be either route cache misses (-F) or hits (-C).
Iface: Interface to which packets for this route will be sent.
MSS: Default maximum segement size for TCP connections over this route.
Window: Default window size for TCP connections over this route.
irtt: Initial RTT (Round Trip Time). The kernel uses this to guess about the best TCP protocol parameters without waiting on (possibly slow) answers.
HH (cached only): The number of ARP entries and cached routes that refer to the hardware header cache for the cached route. This will be -1 if a hardware address is not needed for the interface of the cached route (e.g. lo).
Arp (cached only): Whether or not the hardware address for the cached route is up to date.

FILES

/proc/net/ipv6_route
/proc/net/route
/proc/net/rt_cache