


ROUTE(8)	    Linux Programmer's Manual		 ROUTE(8)


NAME

       route - show / manipulate the IP routing table
       route - ʾ / IPѡ·

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 table.	 Its pri
       mary  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.
	   routeں˵IPѡ·вҪͨifconfig(8)
	   úõĽӿָþ̬·ɡ

OPTIONS
ѡ
       -v     
	      select verbose operation.
	      ѡϸڲģʽ

       -A family
	      Use   the	 specified  address  family  (eg  `inet',
	      `inet6').
		  ָĵַ(`inet'`inet6')

       -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.
		  ʽʽʾַͼ
		  ·ɷϵԭǳá

       -e     
	      use  netstat(8)-format  for  displaying the routing
	      table.  -ee will generate a very long line with all
	      parameters from the routing table.
		  netstat(8)ĸʽʾѡ·-eeѡ·
		  вڵĴϢ

       -net   
	      the target is a network.
		  ·ĿΪ硣

       -host  
	      the target is a host.
		  ·ĿΪ

       -F     
	      displays	the  kernel FIB routing table. The layout
	      can be changed with -e and -ee
		  ʾں˵FIBѡ·ʽ-e  -eeѡı䡣

       -C     
	      displays the kernel's route cache.
		  ʾں˵·ɻ档

       del    
	      deletes a route.
		  ɾһ·ɡ

       add    
	      adds a route.
		  һ·ɡ

       target 
	      The destination network or host. You can provide IP
	      addresses	 in dotted decimal or host/network names.
		  ָĿõʮʽIPַ/
		  

       netmask Nm
	      modifier specifies the netmask of the route  to  be
	      added.
		  Ϊӵ·ָ롣

       gw Gw  
	      Any  IP packets for the target network/host will be
	      routed through the specified  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  com
	      patibility hack.
		  ΪĿ/κηָءע⣺ָ
		  ȱǿɴġҲ˵ΪԤָһ
		  ̬·ɡΪؽӿ֮һָصַĻ
		  ôصַھ˽ӿϵķ齫ν·ɡ
		  BSDݵġ

       metric M
	      Set  the metric field in the routing table (used by
	      routing daemons) to M.
		  ѡ·е·ֵֶ(ѡ·ʹ)ΪM

       mss M  
	      Set the TCP Maximum Segment Size (MSS) for  connec
	      tions  over this route to M bytes. This is normally
	      used only for fine optimisation of routing  setups.
	      The default is 536.
		  ѻڴ·֮ϵӵTCPĶγΪMֽڡ
		  ֻͨŻѡ·áĬֵΪ536

       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.
		  ѻڴ·֮ϵӵTCPڳΪWֽڡͨ
		  ֻAX.25ͲܴԱʽ֡豸

       irtt I 
	      Set the initial round trip time (irtt) for TCP con
	      nections	 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.
		  ѻڴ·֮ϵTCPӵĳʼʱΪI(1-
		  12000)ͨҲֻAX.25硣ʡԴѡ
		  ʹRFC1122ȱʡֵ300ms

       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.
		  һ·ʹһ·ɲʧܡʹȱʡ
		  ·ǰεһЩ硣Ⲣ𵽷ǽá

       mod, dyn, reinstate
	      Install a dynamic or modified route. Both flags are
	      generally only set by a  routing	daemon.	 This  is
	      only for diagnostic purpose.
		  һ̬ĻĹ·ɡЩ־ֻͨѡ·
		  áֻĿģ

       dev If 
	      Forces  the  route to be associated with the speci
	      fied 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.
		  ǿʹ·ָ豸Ϊں˻Լͼ
		  Ӧ豸(ͨѴڵ·ɺͼ·ɵ豸Ĺ)
		  ڶʹá

	      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.
		  dev IfһָѡôʡԹؼ
		  devΪȱʡֵ·޸Ķ(metric - netmask
		  - gw - dev)޹ؽҪ

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  desti
	      nation address) and associated with the "lo" device
	      (assuming this device was	 prviously  set	 up  cor
	      rectly with ifconfig(8)).
		  Ļؽӿʹ255.0.0.0(Ŀַ
		  A)豸"lo"(ٶ豸ǰ
		  ifconfig(8)ȷ)

       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  neces
	      sary  here  because  192.* is a Class C IP address.
	      The word "dev" can be omitted here.
		  "eth0"һָ192.56.76.x·ɡеC
		  벢룬Ϊ192.*ǸCIPַڴ˹ؼ"dev"
		  ʡԡ

       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.
		  һȱʡ·(޷ƥ·)ʹô·
		  ɵз齫ͨ"mango-gw"д䡣ʵʹô
		  ·ɵ豸ȡε"mango-gw" - ǰõ
		  "mango-gw"ľ̬·ɡ

       route add ipx4 sl0
	      Adds  the	 route	to  the	 "ipx4" host via the SLIP
	      interface (assuming that "ipx4" is the SLIP  host).
		  SLIPӿһָ"ipx4"·(ٶ"ipx4"ʹSLIP
		  )

       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.
		  ΪǰSLIPӿڵipx4ӵ"192.57.66.x"
		  ·ɡ

       route add 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  (multi
	      cast)  IP routes to go via "eth0". This is the cor
	      rect normal configuration line with a  multicasting
	      kernel.
		  Ϊ"eth0"趨Dַ(鲥)·ɡ
		  鲥ں˵ȷС

       route add 10.0.0.0 netmask 255.0.0.0 reject
	      This  installs  a	 rejecting  route for the private
	      network "10.x.x.x."
		  Ϊ˽"10.x.x.x."һ·ɡ

OUTPUT
Ϣ
       The output of the kernel routing table is organized in the
       following columns
	   ںѡ·ϢĿɣ

       Destination
	      The destination network or destination host.
		  ĿĿ

       Gateway
	      The gateway address or '*' if none set.
		  صַ'*'(δ)

       Genmask
	      The    netmask	for    the    destination    net;
	      '255.255.255.255'	 for  a	 host	destination   and
	      '0.0.0.0' for the default route.
		  Ŀ룻'255.255.255.255'Ϊ
		  '0.0.0.0'Ϊȱʡ·ɡ

       Flags  
	      Possible flags are
		  ֵܳı־У
	      U (route is up)
		  ·
	      H (target is a host)
		  ·
	      G (use gateway)
		  ʹصļ·
	      R (reinstate route for dynamic routing)
		  Ϊ̬ѡ·ָ·
	      D (dynamically installed by daemon or redirect)
		  ·ѡ·̻ض̬
	      M (modified from routing daemon or rederict)
	      ·ѡ·̻ض޸
		  !	 (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.
		  ͨĿľ(ͨ)ں˲ʹô˸
		  ѡ·ܻ̿á

       Ref    
	      Number  of  references  to this route. (Not used in
	      the Linux kernel.)
		  ʹô·ɵĻ̸(Linuxں˲ʹ)

       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).
		  Ҵ·ɵĴ-F   -Cʹãֵ·
		  ʧ

       Iface  
	      Interface to which packets for this route	 will  be
	      sent.
		  ʹô·ɷͷĽӿڡ

       MSS    
	      Default  maximum	segement size for TCP connections
	      over this route.
		  ڴ·ɵTCPӵȱʡĶγȡ

       Window 
	      Default window size for TCP connections  over  this
	      route.
		  ڴ·ɵTCPӵȱʡڳȡ

       irtt   
	      Initial RTT (Round Trip Time). The kernel uses this
	      to guess about the  best	TCP  protocol  parameters
	      without waiting on (possible slow) answers.
		  ʼʱ䡣ں²TCPЭȴ
		  (ܺ)Ӧ

       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).
		  Ϊ·ɶӲͷARP¼ͻ·
		  ·ɵĽӿ(lo)ӲֵַΪ
		  -1

       Arp (cached only)
	      Whether  or not the hardware address for the cached
	      route is up to date.
		  ۻ·õӲַζи¡

FILES
ļ
       /proc/net/ipv6_route
       /proc/net/route
       /proc/net/rt_cache

SEE ALSO

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

HISTORY
ʷ¼
       Route for Linux was originally written  by  Fred	 N.   van
       Kempen,	<waltje@uwalt.nl.mugnet.org> and then modified by
       Johannes Stille and Linus  Torvalds  for	 pl15.	Alan  Cox
       added  the  mss	and window options for Linux 1.1.22. irtt
       support and merged with netstat from Bernd Eckenfels.
	   LinuxõrouteFred	 N.   van Kempen 
	   <waltje@uwalt.nl.mugnet.org>Johannes Stille 
	   Linus  Torvaldspl15޸ġAlan  CoxΪLinux 1.1.22
	   mss  windowѡirttֺ֧netstatĺϲBernd
	   EckenfelsĹ

AUTHOR

       Currently  maintained  by  Phil	 Blundell   <Philip.Blun
       dell@pobox.com>.
	   ǰPhil Blundell <Philip.Blundell@pobox.com>ά

[İά] meaculpa email:meaculpa@21cn.com
[İ¸] 2000/12/08
MAN-PAGEƻ:http://www.cmpp.net/