ROUTE(8)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Linux System Administrator’s Manual\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ROUTE(8)<\/p>\n
NAME\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
route – show \/ manipulate the IP routing table<\/p>\n
SYNOPSIS\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
route [-CFvnNee] [-A family |-4|-6]<\/p>\n
route\u00a0 [-v] [-A family |-4|-6] add [-net|-host] target [netmask Nm]
\n[gw Gw] [metric N] [mss M] [window W] [irtt I] [reject] [mod]
\n[dyn] [reinstate] [[dev] If]<\/p>\n
route\u00a0 [-v] [-A family |-4|-6] del [-net|-host] target [gw Gw]
\n[netmask Nm] [metric M] [[dev] If]<\/p>\n
route\u00a0 [-V] [–version] [-h] [–help]<\/p>\n
DESCRIPTION\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
Route manipulates the kernel’s IP routing tables.\u00a0 Its primary use is
\nto set up static routes to specific hosts or networks via an
\ninterface after it has been configured with the ifconfig(8) program.<\/p>\n
When the add or del options are used, route modifies the routing
\ntables.\u00a0 Without these options, route displays the current contents
\nof the routing tables.<\/p>\n
OPTIONS\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
-A family
\nuse the specified address family (eg `inet’). Use route –help
\nfor a full list. You can use -6 as an alias for –inet6 and -4
\nas an alias for -A inet<\/p>\n
-F\u00a0\u00a0\u00a0\u00a0 operate on the kernel’s FIB (Forwarding Information Base)
\nrouting table.\u00a0 This is the default.<\/p>\n
-C\u00a0\u00a0\u00a0\u00a0 operate on the kernel’s routing cache.<\/p>\n
-v\u00a0\u00a0\u00a0\u00a0 select verbose operation.<\/p>\n
-n\u00a0\u00a0\u00a0\u00a0 show numerical addresses instead of trying to determine
\nsymbolic host names. This is useful if you are trying to
\ndetermine why the route to your nameserver has vanished.<\/p>\n
-e\u00a0\u00a0\u00a0\u00a0 use netstat(8)-format for displaying the routing table.\u00a0 -ee
\nwill generate a very long line with all parameters from the
\nrouting table.<\/p>\n
del\u00a0\u00a0\u00a0 delete a route.<\/p>\n
add\u00a0\u00a0\u00a0 add a new route.<\/p>\n
target the destination network or host. You can provide an addresses
\nor symbolic network or host name. Optionally you can use
\n\/prefixlen notation instead of using the netmask option.<\/p>\n
-net\u00a0\u00a0 the target is a network.<\/p>\n
-host\u00a0 the target is a host.<\/p>\n
netmask NM
\nwhen adding a network route, the netmask to be used.<\/p>\n
gw GW\u00a0 route packets via a gateway.
\nNOTE: The specified gateway must be reachable first. This
\nusually means that you have to set up a static route to the
\ngateway beforehand. If you specify the address of one of your
\nlocal interfaces, it will be used to decide about the
\ninterface to which the packets should be routed to. This is a
\nBSDism compatibility hack.<\/p>\n
metric M
\nset the metric field in the routing table (used by routing
\ndaemons) to M. If this option is not specified the metric for
\ninet6 (IPv6) address family defaults to ‘1’, for inet (IPv4)
\nit defaults to ‘0’. You should always specify an explicit
\nmetric value to not rely on those defaults – they also differ
\nfrom iproute2.<\/p>\n
mss M\u00a0 sets MTU (Maximum Transmission Unit) of the route to M bytes.
\nNote that the current implementation of the route command does
\nnot allow the option to set the Maximum Segment Size (MSS).<\/p>\n
window W
\nset the TCP window size for connections over this route to W
\nbytes. This is typically only used on AX.25 networks and with
\ndrivers unable to handle back to back frames.<\/p>\n
irtt I set the initial round trip time (irtt) for TCP connections
\nover this route to I milliseconds (1-12000). This is typically
\nonly used on AX.25 networks. If omitted the RFC 1122 default
\nof 300ms is used.<\/p>\n
reject install a blocking route, which will force a route lookup to
\nfail.\u00a0 This is for example used to mask out networks before
\nusing the default route. This is NOT for firewalling.<\/p>\n
mod, dyn, reinstate
\ninstall a dynamic or modified route. These flags are for
\ndiagnostic purposes, and are generally only set by routing
\ndaemons.<\/p>\n
dev If force the route to be associated with the specified device, as
\nthe kernel will otherwise try to determine the device on its
\nown (by checking already existing routes and device
\nspecifications, and where the route is added to). In most
\nnormal networks you won’t need this.<\/p>\n
If dev If is the last option on the command line, the word dev
\nmay be omitted, as it’s the default. Otherwise the order of
\nthe route modifiers (metric netmask gw dev) doesn’t matter.<\/p>\n
EXAMPLES\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
route add -net 127.0.0.0 netmask 255.0.0.0 metric 1024 dev lo
\nadds the normal loopback entry, using netmask 255.0.0.0 and
\nassociated with the “lo” device (assuming this device was
\npreviously set up correctly with ifconfig(8)).<\/p>\n
route add -net 192.56.76.0 netmask 255.255.255.0 metric 1024 dev eth0
\nadds a route to the local network 192.56.76.x via “eth0”.\u00a0 The
\nword “dev” can be omitted here.<\/p>\n
route del default
\ndeletes the current default route, which is labeled “default”
\nor 0.0.0.0 in the destination field of the current routing
\ntable.<\/p>\n
route add default gw mango
\nadds a default route (which will be used if no other route
\nmatches).\u00a0 All packets using this route will be gatewayed
\nthrough the address of a node named “mango”. The device which
\nwill actually be used for that route depends on how we can
\nreach “mango” – “mango” must be on directly reachable route.<\/p>\n
route add mango sl0
\nAdds the route to the host named “mango” via the SLIP
\ninterface (assuming that “mango” is the SLIP host).<\/p>\n
route add -net 192.57.66.0 netmask 255.255.255.0 gw mango
\nThis command adds the net “192.57.66.x” to be gatewayed
\nthrough the former route to the SLIP interface.<\/p>\n
route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0
\nThis is an obscure one documented so people know how to do it.
\nThis sets all of the class D (multicast) IP routes to go via
\n“eth0”. This is the correct normal configuration line with a
\nmulticasting kernel.<\/p>\n
route add -net 10.0.0.0 netmask 255.0.0.0 metric 1024 reject
\nThis installs a rejecting route for the private network
\n“10.x.x.x.”<\/p>\n
route -6 add 2001:0002::\/48 metric 1 dev eth0
\nThis adds a IPv6 route with the specified metric to be
\ndirectly reachable via eth0.<\/p>\n
OUTPUT\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
The output of the kernel routing table is organized in the following
\ncolumns<\/p>\n
Destination
\nThe destination network or destination host.<\/p>\n
Gateway
\nThe gateway address or ‘*’ if none set.<\/p>\n
Genmask
\nThe netmask for the destination net; ‘255.255.255.255’ for a
\nhost destination and ‘0.0.0.0’ for the default route.<\/p>\n
Flags\u00a0 Possible flags include
\nU (route is up)
\nH (target is a host)
\nG (use gateway)
\nR (reinstate route for dynamic routing)
\nD (dynamically installed by daemon or redirect)
\nM (modified from routing daemon or redirect)
\nA (installed by addrconf)
\nC (cache entry)
\n!\u00a0 (reject route)<\/p>\n
Metric The ‘distance’ to the target (usually counted in hops).<\/p>\n
Ref\u00a0\u00a0\u00a0 Number of references to this route. (Not used in the Linux
\nkernel.)<\/p>\n
Use\u00a0\u00a0\u00a0 Count of lookups for the route.\u00a0 Depending on the use of -F
\nand -C this will be either route cache misses (-F) or hits
\n(-C).<\/p>\n
Iface\u00a0 Interface to which packets for this route will be sent.<\/p>\n
MSS\u00a0\u00a0\u00a0 Default maximum segment size for TCP connections over this
\nroute.<\/p>\n
Window Default window size for TCP connections over this route.<\/p>\n
irtt\u00a0\u00a0 Initial RTT (Round Trip Time). The kernel uses this to guess
\nabout the best TCP protocol parameters without waiting on
\n(possibly slow) answers.<\/p>\n
HH (cached only)
\nThe number of ARP entries and cached routes that refer to the
\nhardware header cache for the cached route. This will be -1 if
\na hardware address is not needed for the interface of the
\ncached route (e.g. lo).<\/p>\n
Arp (cached only)
\nWhether or not the hardware address for the cached route is up
\nto date.<\/p>\n
FILES\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
\/proc\/net\/ipv6_route
\n\/proc\/net\/route
\n\/proc\/net\/rt_cache<\/p>\n
SEE ALSO\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
ifconfig(8), netstat(8), arp(8), rarp(8), ip(8)<\/p>\n
HISTORY\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
Route for Linux was originally written by Fred N.\u00a0 van Kempen,
\n<waltje@uwalt.nl.mugnet.org> and then modified by Johannes Stille and
\nLinus Torvalds for pl15. Alan Cox added the mss and window options
\nfor Linux 1.1.22. irtt support and merged with netstat from Bernd
\nEckenfels.<\/p>\n
AUTHOR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
Currently maintained by Phil Blundell <Philip.Blundell@pobox.com> and
\nBernd Eckenfels <net-tools@lina.inka.de>.<\/p>\n
COLOPHON\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top<\/p>\n
This page is part of the net-tools (networking utilities) project.
\nInformation about the project can be found at
\n\u27e8http:\/\/net-tools.sourceforge.net\/\u27e9.\u00a0 If you have a bug report for
\nthis manual page, see \u27e8http:\/\/net-tools.sourceforge.net\/\u27e9.\u00a0 This page
\nwas obtained from the project’s upstream Git repository
\n(git:\/\/git.code.sf.net\/p\/net-tools\/code) on 2014-12-30.\u00a0 If you dis\u2010
\ncover any rendering problems in this HTML version of the page, or you
\nbelieve there is a better or more up-to-date source for the page, or
\nyou have corrections or improvements to the information in this
\nCOLOPHON (which is not part of the original manual page), send a mail
\nto\u00a0man-pages@man7.org<\/p>\n
net-tools\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2014-02-17\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ROUTE(8)<\/p>\n","protected":false},"excerpt":{"rendered":"
ROUTE(8)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Linux System Administrator’s Manual\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ROUTE(8) NAME\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top route – show \/ manipulate the IP routing table SYNOPSIS\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 top route [-CFvnNee] [-A family |-4|-6] route\u00a0 [-v] [-A family |-4|-6] add [-net|-host] target [netmask Nm] [gw Gw] [metric N] [mss M] [window W] [irtt I] [reject] [mod] [dyn] [reinstate] [[dev] If] route\u00a0 [-v] [-A family |-4|-6] […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"categories":[8],"tags":[],"class_list":["post-339","post","type-post","status-publish","format-standard","hentry","category-shell"],"a3_pvc":{"activated":false,"total_views":0,"today_views":0},"_links":{"self":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts\/339","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=339"}],"version-history":[{"count":0,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts\/339\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=339"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=339"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=339"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}