1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)route.8 8.3 (Berkeley) 3/19/94 29.\" $FreeBSD$ 30.\" 31.Dd October 2, 2005 32.Dt ROUTE 8 33.Os 34.Sh NAME 35.Nm route 36.Nd manually manipulate the routing tables 37.Sh SYNOPSIS 38.Nm 39.Op Fl dnqtv 40.Ar command 41.Oo 42.Op Ar modifiers 43.Ar args 44.Oc 45.Sh DESCRIPTION 46The 47.Nm 48utility is used to manually manipulate the network 49routing tables. 50It normally is not needed, as a 51system routing table management daemon, such as 52.Xr routed 8 , 53should tend to this task. 54.Pp 55The 56.Nm 57utility supports a limited number of general options, 58but a rich command language, enabling the user to specify 59any arbitrary request that could be delivered via the 60programmatic interface discussed in 61.Xr route 4 . 62.Pp 63The following options are available: 64.Bl -tag -width indent 65.It Fl d 66Run in debug-only mode, i.e., do not actually modify the routing table. 67.It Fl n 68Bypass attempts to print host and network names symbolically 69when reporting actions. 70(The process of translating between symbolic 71names and numerical equivalents can be quite time consuming, and 72may require correct operation of the network; thus it may be expedient 73to forget this, especially when attempting to repair networking operations). 74.It Fl v 75(verbose) Print additional details. 76.It Fl q 77Suppress all output from the 78.Cm add , change , delete , 79and 80.Cm flush 81commands. 82.El 83.Pp 84The 85.Nm 86utility provides the following commands: 87.Pp 88.Bl -tag -width Fl -compact 89.It Cm add 90Add a route. 91.It Cm flush 92Remove all routes. 93.It Cm delete 94Delete a specific route. 95.It Cm del 96Another name for the 97.Cm delete 98command. 99.It Cm change 100Change aspects of a route (such as its gateway). 101.It Cm get 102Lookup and display the route for a destination. 103.It Cm monitor 104Continuously report any changes to the routing information base, 105routing lookup misses, or suspected network partitionings. 106.El 107.Pp 108The monitor command has the syntax: 109.Pp 110.Bd -ragged -offset indent -compact 111.Nm 112.Op Fl n 113.Cm monitor 114.Ed 115.Pp 116The flush command has the syntax: 117.Pp 118.Bd -ragged -offset indent -compact 119.Nm 120.Op Fl n 121.Cm flush 122.Op Ar family 123.Ed 124.Pp 125If the 126.Cm flush 127command is specified, 128.Nm 129will ``flush'' the routing tables of all gateway entries. 130When the address family may is specified by any of the 131.Fl osi , 132.Fl xns , 133.Fl atalk , 134.Fl inet6 , 135or 136.Fl inet 137modifiers, only routes having destinations with addresses in the 138delineated family will be deleted. 139.Pp 140The other commands have the following syntax: 141.Pp 142.Bd -ragged -offset indent -compact 143.Nm 144.Op Fl n 145.Ar command 146.Op Fl net No \&| Fl host 147.Ar destination gateway 148.Op Ar netmask 149.Ed 150.Pp 151where 152.Ar destination 153is the destination host or network, 154.Ar gateway 155is the next-hop intermediary via which packets should be routed. 156Routes to a particular host may be distinguished from those to 157a network by interpreting the Internet address specified as the 158.Ar destination 159argument. 160The optional modifiers 161.Fl net 162and 163.Fl host 164force the destination to be interpreted as a network or a host, respectively. 165Otherwise, if the 166.Ar destination 167has a 168.Dq local address part 169of 170INADDR_ANY 171.Pq Li 0.0.0.0 , 172or if the 173.Ar destination 174is the symbolic name of a network, then the route is 175assumed to be to a network; otherwise, it is presumed to be a 176route to a host. 177Optionally, the 178.Ar destination 179could also be specified in the 180.Ar net Ns / Ns Ar bits 181format. 182.Pp 183For example, 184.Li 128.32 185is interpreted as 186.Fl host Li 128.0.0.32 ; 187.Li 128.32.130 188is interpreted as 189.Fl host Li 128.32.0.130 ; 190.Fl net Li 128.32 191is interpreted as 192.Li 128.32.0.0; 193.Fl net Li 128.32.130 194is interpreted as 195.Li 128.32.130.0; 196and 197.Li 192.168.64/20 198is interpreted as 199.Fl net Li 192.168.64 Fl netmask Li 255.255.240.0 . 200.Pp 201A 202.Ar destination 203of 204.Ar default 205is a synonym for 206.Fl net Li 0.0.0.0 , 207which is the default route. 208.Pp 209If the destination is directly reachable 210via an interface requiring 211no intermediary system to act as a gateway, the 212.Fl interface 213modifier should be specified; 214the gateway given is the address of this host on the common network, 215indicating the interface to be used for transmission. 216Alternately, if the interface is point to point the name of the interface 217itself may be given, in which case the route remains valid even 218if the local or remote addresses change. 219.Pp 220The optional modifiers 221.Fl xns , 222.Fl osi , 223.Fl atalk , 224and 225.Fl link 226specify that all subsequent addresses are in the 227.Tn XNS , 228.Tn OSI , 229or 230.Tn AppleTalk 231address families, 232or are specified as link-level addresses, 233and the names must be numeric specifications rather than 234symbolic names. 235.Pp 236The optional 237.Fl netmask 238modifier is intended 239to achieve the effect of an 240.Tn OSI 241.Tn ESIS 242redirect with the netmask option, 243or to manually add subnet routes with 244netmasks different from that of the implied network interface 245(as would otherwise be communicated using the OSPF or ISIS routing protocols). 246One specifies an additional ensuing address parameter 247(to be interpreted as a network mask). 248The implicit network mask generated in the AF_INET case 249can be overridden by making sure this option follows the destination parameter. 250.Pp 251For 252.Dv AF_INET6 , 253the 254.Fl prefixlen 255qualifier 256is available instead of the 257.Fl mask 258qualifier because non-continuous masks are not allowed in IPv6. 259For example, 260.Fl prefixlen Li 32 261specifies network mask of 262.Li ffff:ffff:0000:0000:0000:0000:0000:0000 263to be used. 264The default value of prefixlen is 64 to get along with 265the aggregatable address. 266But 0 is assumed if 267.Cm default 268is specified. 269Note that the qualifier works only for 270.Dv AF_INET6 271address family. 272.Pp 273Routes have associated flags which influence operation of the protocols 274when sending to destinations matched by the routes. 275These flags may be set (or sometimes cleared) 276by indicating the following corresponding modifiers: 277.Bd -literal 278-cloning RTF_CLONING - generates a new route on use 279-xresolve RTF_XRESOLVE - emit mesg on use (for external lookup) 280-iface ~RTF_GATEWAY - destination is directly reachable 281-static RTF_STATIC - manually added route 282-nostatic ~RTF_STATIC - pretend route added by kernel or daemon 283-reject RTF_REJECT - emit an ICMP unreachable when matched 284-blackhole RTF_BLACKHOLE - silently discard pkts (during updates) 285-proto1 RTF_PROTO1 - set protocol specific routing flag #1 286-proto2 RTF_PROTO2 - set protocol specific routing flag #2 287-llinfo RTF_LLINFO - validly translates proto addr to link addr 288.Ed 289.Pp 290The optional modifiers 291.Fl rtt , 292.Fl rttvar , 293.Fl sendpipe , 294.Fl recvpipe , 295.Fl mtu , 296.Fl hopcount , 297.Fl expire , 298and 299.Fl ssthresh 300provide initial values to quantities maintained in the routing entry 301by transport level protocols, such as TCP or TP4. 302These may be individually locked by preceding each such modifier to 303be locked by 304the 305.Fl lock 306meta-modifier, or one can 307specify that all ensuing metrics may be locked by the 308.Fl lockrest 309meta-modifier. 310.Pp 311In a 312.Cm change 313or 314.Cm add 315command where the destination and gateway are not sufficient to specify 316the route (as in the 317.Tn ISO 318case where several interfaces may have the 319same address), the 320.Fl ifp 321or 322.Fl ifa 323modifiers may be used to determine the interface or interface address. 324.Pp 325The optional 326.Fl proxy 327modifier specifies that the 328.Dv RTF_LLINFO 329routing table entry is the 330.Dq published (proxy-only) 331.Tn ARP 332entry, as reported by 333.Xr arp 8 . 334.Pp 335The optional 336.Fl genmask 337modifier specifies that a cloning mask is present. 338This specifies the mask applied when determining if a child route 339should be created. 340It is only applicable to network routes with the 341.Dv RTF_CLONING 342flag set. 343.Pp 344All symbolic names specified for a 345.Ar destination 346or 347.Ar gateway 348are looked up first as a host name using 349.Xr gethostbyname 3 . 350If this lookup fails, 351.Xr getnetbyname 3 352is then used to interpret the name as that of a network. 353.Pp 354The 355.Nm 356utility uses a routing socket and the new message types 357.Dv RTM_ADD , RTM_DELETE , RTM_GET , 358and 359.Dv RTM_CHANGE . 360As such, only the super-user may modify 361the routing tables. 362.Sh EXIT STATUS 363.Ex -std 364.Sh DIAGNOSTICS 365.Bl -diag 366.It "add [host \&| network ] %s: gateway %s flags %x" 367The specified route is being added to the tables. 368The 369values printed are from the routing table entry supplied 370in the 371.Xr ioctl 2 372call. 373If the gateway address used was not the primary address of the gateway 374(the first one returned by 375.Xr gethostbyname 3 ) , 376the gateway address is printed numerically as well as symbolically. 377.It "delete [ host \&| network ] %s: gateway %s flags %x" 378As above, but when deleting an entry. 379.It "%s %s done" 380When the 381.Cm flush 382command is specified, each routing table entry deleted 383is indicated with a message of this form. 384.It "Network is unreachable" 385An attempt to add a route failed because the gateway listed was not 386on a directly-connected network. 387The next-hop gateway must be given. 388.It "not in table" 389A delete operation was attempted for an entry which 390was not present in the tables. 391.It "routing table overflow" 392An add operation was attempted, but the system was 393low on resources and was unable to allocate memory 394to create the new entry. 395.It "gateway uses the same route" 396A 397.Cm change 398operation resulted in a route whose gateway uses the 399same route as the one being changed. 400The next-hop gateway should be reachable through a different route. 401.El 402.Sh SEE ALSO 403.\".Xr esis 4 , 404.Xr netintro 4 , 405.Xr route 4 , 406.Xr arp 8 , 407.Xr IPXrouted 8 , 408.Xr routed 8 409.\".Xr XNSrouted 8 410.Sh HISTORY 411The 412.Nm 413utility appeared in 414.Bx 4.2 . 415.Sh BUGS 416The first paragraph may have slightly exaggerated 417.Xr routed 8 Ns 's 418abilities. 419.Pp 420Currently, routes with the 421.Dv RTF_BLACKHOLE 422flag set need to have the gateway set to an instance of the 423.Xr lo 4 424driver, using the 425.Fl iface 426option, for the flag to have any effect; unless IP fast forwarding 427is enabled, in which case the meaning of the flag will always 428be honored. 429