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Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)route.8 8.3 (Berkeley) 3/19/94 .\" $FreeBSD: src/sbin/route/route.8,v 126.96.36.199 2001/10/02 10:04:01 ru Exp $ .\" .Dd June 8, 2001 .Dt ROUTE 8 .Os BSD 4.4 .Sh NAME .Nm route .Nd manually manipulate the routing tables .Sh SYNOPSIS .Nm .Op Fl dnqtv .Ar command .Oo .Op Ar modifiers .Ar args .Oc .Sh DESCRIPTION .Nm Route is a utility used to manually manipulate the network routing tables. It normally is not needed, as a system routing table management daemon such as .Xr routed 8 , should tend to this task. .Pp The .Nm utility supports a limited number of general options, but a rich command language, enabling the user to specify any arbitrary request that could be delivered via the programmatic interface discussed in .Xr route 4 . .Pp The following options are available: .Bl -tag -width indent .It Fl d Run in debug-only mode, i.e., do not actually modify the routing table. .It Fl n Bypass attempts to print host and network names symbolically when reporting actions. (The process of translating between symbolic names and numerical equivalents can be quite time consuming, and may require correct operation of the network; thus it may be expedient to forget this, especially when attempting to repair networking operations). .It Fl t Run in test-only mode. .Pa /dev/null is used instead of a socket. .It Fl v (verbose) Print additional details. .It Fl q Suppress all output. .El .Pp The .Nm utility provides six commands: .Pp .Bl -tag -width Fl -compact .It Cm add Add a route. .It Cm flush Remove all routes. .It Cm delete Delete a specific route. .It Cm change Change aspects of a route (such as its gateway). .It Cm get Lookup and display the route for a destination. .It Cm monitor Continuously report any changes to the routing information base, routing lookup misses, or suspected network partitionings. .El .Pp The monitor command has the syntax: .Pp .Bd -ragged -offset indent -compact .Nm .Op Fl n .Cm monitor .Ed .Pp The flush command has the syntax: .Pp .Bd -ragged -offset indent -compact .Nm .Op Fl n .Cm flush .Op Ar family .Ed .Pp If the .Cm flush command is specified, .Nm will ``flush'' the routing tables of all gateway entries. When the address family may is specified by any of the .Fl osi , .Fl xns , .Fl atalk , .Fl inet6 , or .Fl inet modifiers, only routes having destinations with addresses in the delineated family will be deleted. .Pp The other commands have the following syntax: .Pp .Bd -ragged -offset indent -compact .Nm .Op Fl n .Ar command .Op Fl net No \&| Fl host .Oo Fl ifscope .Ar boundif .Oc .Ar destination gateway .Op Ar netmask .Ed .Pp where .Ar destination is the destination host or network, .Ar gateway is the next-hop intermediary via which packets should be routed. Routes to a particular host may be distinguished from those to a network by interpreting the Internet address specified as the .Ar destination argument. The optional modifiers .Fl net and .Fl host force the destination to be interpreted as a network or a host, respectively. Otherwise, if the .Ar destination has a .Dq local address part of INADDR_ANY .Pq Li 0.0.0.0 , or if the .Ar destination is the symbolic name of a network, then the route is assumed to be to a network; otherwise, it is presumed to be a route to a host. Optionally, the .Ar destination could also be specified in the .Ar net Ns / Ns Ar bits format. .Pp For example, .Li 128.32 is interpreted as .Fl host Li 188.8.131.52 ; .Li 128.32.130 is interpreted as .Fl host Li 184.108.40.206 ; .Fl net Li 128.32 is interpreted as .Li 220.127.116.11; .Fl net Li 128.32.130 is interpreted as .Li 18.104.22.168; and .Li 192.168.64/20 is interpreted as .Fl net Li 192.168.64 Fl netmask Li 255.255.240.0 . .Pp A .Ar destination of .Ar default is a synonym for .Fl net Li 0.0.0.0 , which is the default route. .Pp If the destination is directly reachable via an interface requiring no intermediary system to act as a gateway, the .Fl interface modifier should be specified; the gateway given is the address of this host on the common network, indicating the interface to be used for transmission. Alternately, if the interface is point to point the name of the interface itself may be given, in which case the route remains valid even if the local or remote addresses change. .Pp For AF_INET and AF_INET6, the .Fl ifscope modifier specifies the additional property of the route related to the interface scope derived from interface .Ar boundif . Such property allows for the presence of multiple route entries with the same destination, where each route is associated with a unique interface. This modifier is required in order to manipulate route entries marked with the RTF_IFSCOPE flag. .Pp The optional modifier .Fl link specify that all subsequent addresses are specified as link-level addresses, and the names must be numeric specifications rather than symbolic names. .Pp The optional .Fl netmask modifier is intended to achieve the effect of an .Tn OSI .Tn ESIS redirect with the netmask option, or to manually add subnet routes with netmasks different from that of the implied network interface (as would otherwise be communicated using the OSPF or ISIS routing protocols). One specifies an additional ensuing address parameter (to be interpreted as a network mask). The implicit network mask generated in the AF_INET case can be overridden by making sure this option follows the destination parameter. .Pp For .Dv AF_INET6 , the .Fl prefixlen qualifier is available instead of the .Fl mask qualifier because non-continuous masks are not allowed in IPv6. For example, .Fl prefixlen Li 32 specifies network mask of .Li ffff:ffff:0000:0000:0000:0000:0000:0000 to be used. The default value of prefixlen is 64 to get along with the aggregatable address. But 0 is assumed if .Cm default is specified. Note that the qualifier works only for .Dv AF_INET6 address family. .Pp Routes have associated flags which influence operation of the protocols when sending to destinations matched by the routes. These flags may be set (or sometimes cleared) by indicating the following corresponding modifiers: .Bd -literal -cloning RTF_CLONING - generates a new route on use -xresolve RTF_XRESOLVE - emit mesg on use (for external lookup) -iface ~RTF_GATEWAY - destination is directly reachable -static RTF_STATIC - manually added route -nostatic ~RTF_STATIC - pretend route added by kernel or daemon -reject RTF_REJECT - emit an ICMP unreachable when matched -blackhole RTF_BLACKHOLE - silently discard pkts (during updates) -proto1 RTF_PROTO1 - set protocol specific routing flag #1 -proto2 RTF_PROTO2 - set protocol specific routing flag #2 -llinfo RTF_LLINFO - validly translates proto addr to link addr .Ed .Pp The optional modifiers .Fl rtt , .Fl rttvar , .Fl sendpipe , .Fl recvpipe , .Fl mtu , .Fl hopcount , .Fl expire , and .Fl ssthresh provide initial values to quantities maintained in the routing entry by transport level protocols, such as TCP or TP4. These may be individually locked by preceding each such modifier to be locked by the .Fl lock meta-modifier, or one can specify that all ensuing metrics may be locked by the .Fl lockrest meta-modifier. .Pp In a .Cm change or .Cm add command where the destination and gateway are not sufficient to specify the route (as in the .Tn ISO case where several interfaces may have the same address), the .Fl ifp or .Fl ifa modifiers may be used to determine the interface or interface address. .Pp The optional .Fl proxy modifier specifies that the .Dv RTF_LLINFO routing table entry is the .Dq published (proxy-only) .Tn ARP entry, as reported by .Xr arp 8 . .Pp All symbolic names specified for a .Ar destination or .Ar gateway are looked up first as a host name using .Xr gethostbyname 3 . If this lookup fails, .Xr getnetbyname 3 is then used to interpret the name as that of a network. .Pp .Nm Route uses a routing socket and the new message types .Dv RTM_ADD , RTM_DELETE , RTM_GET , and .Dv RTM_CHANGE . As such, only the super-user may modify the routing tables. .Sh DIAGNOSTICS .Bl -diag .It "add [host \&| network ] %s: gateway %s flags %x" The specified route is being added to the tables. The values printed are from the routing table entry supplied in the .Xr ioctl 2 call. If the gateway address used was not the primary address of the gateway (the first one returned by .Xr gethostbyname 3 ) , the gateway address is printed numerically as well as symbolically. .It "delete [ host \&| network ] %s: gateway %s flags %x" As above, but when deleting an entry. .It "%s %s done" When the .Cm flush command is specified, each routing table entry deleted is indicated with a message of this form. .It "Network is unreachable" An attempt to add a route failed because the gateway listed was not on a directly-connected network. The next-hop gateway must be given. .It "not in table" A delete operation was attempted for an entry which wasn't present in the tables. .It "routing table overflow" An add operation was attempted, but the system was low on resources and was unable to allocate memory to create the new entry. .It "gateway uses the same route" A .Cm change operation resulted in a route whose gateway uses the same route as the one being changed. The next-hop gateway should be reachable through a different route. .El .Pp .Ex -std .Sh SEE ALSO .Xr netintro 4 , .Xr route 4 , .Xr arp 8 , .Xr routed 8 .Sh HISTORY The .Nm command appeared in .Bx 4.2 . .Sh BUGS The first paragraph may have slightly exaggerated .Xr routed 8 Ns 's abilities.