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 June 8, 2001 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. It normally is not needed, as a 50system routing table management daemon, such as 51.Xr routed 8 , 52should tend to this task. 53.Pp 54The 55.Nm 56utility supports a limited number of general options, 57but a rich command language, enabling the user to specify 58any arbitrary request that could be delivered via the 59programmatic interface discussed in 60.Xr route 4 . 61.Pp 62The following options are available: 63.Bl -tag -width indent 64.It Fl d 65Run in debug-only mode, i.e., do not actually modify the routing table. 66.It Fl n 67Bypass attempts to print host and network names symbolically 68when reporting actions. (The process of translating between symbolic 69names and numerical equivalents can be quite time consuming, and 70may require correct operation of the network; thus it may be expedient 71to forget this, especially when attempting to repair networking operations). 72.It Fl v 73(verbose) Print additional details. 74.It Fl q 75Suppress all output from the 76.Cm add , delete , 77and 78.Cm flush 79commands. 80.El 81.Pp 82The 83.Nm 84utility provides six commands: 85.Pp 86.Bl -tag -width Fl -compact 87.It Cm add 88Add a route. 89.It Cm flush 90Remove all routes. 91.It Cm delete 92Delete a specific route. 93.It Cm change 94Change aspects of a route (such as its gateway). 95.It Cm get 96Lookup and display the route for a destination. 97.It Cm monitor 98Continuously report any changes to the routing information base, 99routing lookup misses, or suspected network partitionings. 100.El 101.Pp 102The monitor command has the syntax: 103.Pp 104.Bd -ragged -offset indent -compact 105.Nm 106.Op Fl n 107.Cm monitor 108.Ed 109.Pp 110The flush command has the syntax: 111.Pp 112.Bd -ragged -offset indent -compact 113.Nm 114.Op Fl n 115.Cm flush 116.Op Ar family 117.Ed 118.Pp 119If the 120.Cm flush 121command is specified, 122.Nm 123will ``flush'' the routing tables of all gateway entries. 124When the address family may is specified by any of the 125.Fl osi , 126.Fl xns , 127.Fl atalk , 128.Fl inet6 , 129or 130.Fl inet 131modifiers, only routes having destinations with addresses in the 132delineated family will be deleted. 133.Pp 134The other commands have the following syntax: 135.Pp 136.Bd -ragged -offset indent -compact 137.Nm 138.Op Fl n 139.Ar command 140.Op Fl net No \&| Fl host 141.Ar destination gateway 142.Op Ar netmask 143.Ed 144.Pp 145where 146.Ar destination 147is the destination host or network, 148.Ar gateway 149is the next-hop intermediary via which packets should be routed. 150Routes to a particular host may be distinguished from those to 151a network by interpreting the Internet address specified as the 152.Ar destination 153argument. 154The optional modifiers 155.Fl net 156and 157.Fl host 158force the destination to be interpreted as a network or a host, respectively. 159Otherwise, if the 160.Ar destination 161has a 162.Dq local address part 163of 164INADDR_ANY 165.Pq Li 0.0.0.0 , 166or if the 167.Ar destination 168is the symbolic name of a network, then the route is 169assumed to be to a network; otherwise, it is presumed to be a 170route to a host. 171Optionally, the 172.Ar destination 173could also be specified in the 174.Ar net Ns / Ns Ar bits 175format. 176.Pp 177For example, 178.Li 128.32 179is interpreted as 180.Fl host Li 128.0.0.32 ; 181.Li 128.32.130 182is interpreted as 183.Fl host Li 128.32.0.130 ; 184.Fl net Li 128.32 185is interpreted as 186.Li 128.32.0.0; 187.Fl net Li 128.32.130 188is interpreted as 189.Li 128.32.130.0; 190and 191.Li 192.168.64/20 192is interpreted as 193.Fl net Li 192.168.64 Fl netmask Li 255.255.240.0 . 194.Pp 195A 196.Ar destination 197of 198.Ar default 199is a synonym for 200.Fl net Li 0.0.0.0 , 201which is the default route. 202.Pp 203If the destination is directly reachable 204via an interface requiring 205no intermediary system to act as a gateway, the 206.Fl interface 207modifier should be specified; 208the gateway given is the address of this host on the common network, 209indicating the interface to be used for transmission. 210Alternately, if the interface is point to point the name of the interface 211itself may be given, in which case the route remains valid even 212if the local or remote addresses change. 213.Pp 214The optional modifiers 215.Fl xns , 216.Fl osi , 217.Fl atalk , 218and 219.Fl link 220specify that all subsequent addresses are in the 221.Tn XNS , 222.Tn OSI , 223or 224.Tn AppleTalk 225address families, 226or are specified as link-level addresses, 227and the names must be numeric specifications rather than 228symbolic names. 229.Pp 230The optional 231.Fl netmask 232modifier is intended 233to achieve the effect of an 234.Tn OSI 235.Tn ESIS 236redirect with the netmask option, 237or to manually add subnet routes with 238netmasks different from that of the implied network interface 239(as would otherwise be communicated using the OSPF or ISIS routing protocols). 240One specifies an additional ensuing address parameter 241(to be interpreted as a network mask). 242The implicit network mask generated in the AF_INET case 243can be overridden by making sure this option follows the destination parameter. 244.Pp 245For 246.Dv AF_INET6 , 247the 248.Fl prefixlen 249qualifier 250is available instead of the 251.Fl mask 252qualifier because non-continuous masks are not allowed in IPv6. 253For example, 254.Fl prefixlen Li 32 255specifies network mask of 256.Li ffff:ffff:0000:0000:0000:0000:0000:0000 257to be used. 258The default value of prefixlen is 64 to get along with 259the aggregatable address. 260But 0 is assumed if 261.Cm default 262is specified. 263Note that the qualifier works only for 264.Dv AF_INET6 265address family. 266.Pp 267Routes have associated flags which influence operation of the protocols 268when sending to destinations matched by the routes. 269These flags may be set (or sometimes cleared) 270by indicating the following corresponding modifiers: 271.Bd -literal 272-cloning RTF_CLONING - generates a new route on use 273-xresolve RTF_XRESOLVE - emit mesg on use (for external lookup) 274-iface ~RTF_GATEWAY - destination is directly reachable 275-static RTF_STATIC - manually added route 276-nostatic ~RTF_STATIC - pretend route added by kernel or daemon 277-reject RTF_REJECT - emit an ICMP unreachable when matched 278-blackhole RTF_BLACKHOLE - silently discard pkts (during updates) 279-proto1 RTF_PROTO1 - set protocol specific routing flag #1 280-proto2 RTF_PROTO2 - set protocol specific routing flag #2 281-llinfo RTF_LLINFO - validly translates proto addr to link addr 282.Ed 283.Pp 284The optional modifiers 285.Fl rtt , 286.Fl rttvar , 287.Fl sendpipe , 288.Fl recvpipe , 289.Fl mtu , 290.Fl hopcount , 291.Fl expire , 292and 293.Fl ssthresh 294provide initial values to quantities maintained in the routing entry 295by transport level protocols, such as TCP or TP4. 296These may be individually locked by preceding each such modifier to 297be locked by 298the 299.Fl lock 300meta-modifier, or one can 301specify that all ensuing metrics may be locked by the 302.Fl lockrest 303meta-modifier. 304.Pp 305In a 306.Cm change 307or 308.Cm add 309command where the destination and gateway are not sufficient to specify 310the route (as in the 311.Tn ISO 312case where several interfaces may have the 313same address), the 314.Fl ifp 315or 316.Fl ifa 317modifiers may be used to determine the interface or interface address. 318.Pp 319The optional 320.Fl proxy 321modifier specifies that the 322.Dv RTF_LLINFO 323routing table entry is the 324.Dq published (proxy-only) 325.Tn ARP 326entry, as reported by 327.Xr arp 8 . 328.Pp 329The optional 330.Fl genmask 331modifier specifies that a cloning mask is present. 332This specifies the mask applied when determining if a child route 333should be created. 334It is only applicable to network routes with the 335.Dv RTF_CLONING 336flag set. 337.Pp 338All symbolic names specified for a 339.Ar destination 340or 341.Ar gateway 342are looked up first as a host name using 343.Xr gethostbyname 3 . 344If this lookup fails, 345.Xr getnetbyname 3 346is then used to interpret the name as that of a network. 347.Pp 348The 349.Nm 350utility uses a routing socket and the new message types 351.Dv RTM_ADD , RTM_DELETE , RTM_GET , 352and 353.Dv RTM_CHANGE . 354As such, only the super-user may modify 355the routing tables. 356.Sh DIAGNOSTICS 357.Bl -diag 358.It "add [host \&| network ] %s: gateway %s flags %x" 359The specified route is being added to the tables. The 360values printed are from the routing table entry supplied 361in the 362.Xr ioctl 2 363call. 364If the gateway address used was not the primary address of the gateway 365(the first one returned by 366.Xr gethostbyname 3 ) , 367the gateway address is printed numerically as well as symbolically. 368.It "delete [ host \&| network ] %s: gateway %s flags %x" 369As above, but when deleting an entry. 370.It "%s %s done" 371When the 372.Cm flush 373command is specified, each routing table entry deleted 374is indicated with a message of this form. 375.It "Network is unreachable" 376An attempt to add a route failed because the gateway listed was not 377on a directly-connected network. 378The next-hop gateway must be given. 379.It "not in table" 380A delete operation was attempted for an entry which 381wasn't present in the tables. 382.It "routing table overflow" 383An add operation was attempted, but the system was 384low on resources and was unable to allocate memory 385to create the new entry. 386.It "gateway uses the same route" 387A 388.Cm change 389operation resulted in a route whose gateway uses the 390same route as the one being changed. 391The next-hop gateway should be reachable through a different route. 392.El 393.Pp 394.Ex -std 395.Sh SEE ALSO 396.\".Xr esis 4 , 397.Xr netintro 4 , 398.Xr route 4 , 399.Xr arp 8 , 400.Xr IPXrouted 8 , 401.Xr routed 8 402.\".Xr XNSrouted 8 403.Sh HISTORY 404The 405.Nm 406utility appeared in 407.Bx 4.2 . 408.Sh BUGS 409The first paragraph may have slightly exaggerated 410.Xr routed 8 Ns 's 411abilities. 412