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.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)route.8 8.3 (Berkeley) 3/19/94 33.\" $FreeBSD$ 34.\" 35.Dd June 8, 2001 36.Dt ROUTE 8 37.Os 38.Sh NAME 39.Nm route 40.Nd manually manipulate the routing tables 41.Sh SYNOPSIS 42.Nm 43.Op Fl dnqtv 44.Ar command 45.Oo 46.Op Ar modifiers 47.Ar args 48.Oc 49.Sh DESCRIPTION 50The 51.Nm 52utility is used to manually manipulate the network 53routing tables. It normally is not needed, as a 54system routing table management daemon such as 55.Xr routed 8 , 56should tend to this task. 57.Pp 58The 59.Nm 60utility supports a limited number of general options, 61but a rich command language, enabling the user to specify 62any arbitrary request that could be delivered via the 63programmatic interface discussed in 64.Xr route 4 . 65.Pp 66The following options are available: 67.Bl -tag -width indent 68.It Fl n 69Bypass attempts to print host and network names symbolically 70when reporting actions. (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 , delete , 79and 80.Cm flush 81commands. 82.El 83.Pp 84The 85.Nm 86utility provides six 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 change 96Change aspects of a route (such as its gateway). 97.It Cm get 98Lookup and display the route for a destination. 99.It Cm monitor 100Continuously report any changes to the routing information base, 101routing lookup misses, or suspected network partitionings. 102.El 103.Pp 104The monitor command has the syntax: 105.Pp 106.Bd -ragged -offset indent -compact 107.Nm 108.Op Fl n 109.Cm monitor 110.Ed 111.Pp 112The flush command has the syntax: 113.Pp 114.Bd -ragged -offset indent -compact 115.Nm 116.Op Fl n 117.Cm flush 118.Op Ar family 119.Ed 120.Pp 121If the 122.Cm flush 123command is specified, 124.Nm 125will ``flush'' the routing tables of all gateway entries. 126When the address family may is specified by any of the 127.Fl osi , 128.Fl xns , 129.Fl atalk , 130.Fl inet6 , 131or 132.Fl inet 133modifiers, only routes having destinations with addresses in the 134delineated family will be deleted. 135.Pp 136The other commands have the following syntax: 137.Pp 138.Bd -ragged -offset indent -compact 139.Nm 140.Op Fl n 141.Ar command 142.Op Fl net No \&| Fl host 143.Ar destination gateway 144.Op Ar netmask 145.Ed 146.Pp 147where 148.Ar destination 149is the destination host or network, 150.Ar gateway 151is the next-hop intermediary via which packets should be routed. 152Routes to a particular host may be distinguished from those to 153a network by interpreting the Internet address specified as the 154.Ar destination 155argument. 156The optional modifiers 157.Fl net 158and 159.Fl host 160force the destination to be interpreted as a network or a host, respectively. 161Otherwise, if the 162.Ar destination 163has a 164.Dq local address part 165of 166INADDR_ANY 167.Pq Li 0.0.0.0 , 168or if the 169.Ar destination 170is the symbolic name of a network, then the route is 171assumed to be to a network; otherwise, it is presumed to be a 172route to a host. 173Optionally, the 174.Ar destination 175could also be specified in the 176.Ar net Ns / Ns Ar bits 177format. 178.Pp 179For example, 180.Li 128.32 181is interpreted as 182.Fl host Li 128.0.0.32 ; 183.Li 128.32.130 184is interpreted as 185.Fl host Li 128.32.0.130 ; 186.Fl net Li 128.32 187is interpreted as 188.Li 128.32.0.0; 189.Fl net Li 128.32.130 190is interpreted as 191.Li 128.32.130.0; 192and 193.Li 192.168.64/20 194is interpreted as 195.Fl net Li 192.168.64 Fl netmask Li 255.255.240.0 . 196.Pp 197A 198.Ar destination 199of 200.Ar default 201is a synonym for 202.Fl net Li 0.0.0.0 , 203which is the default route. 204.Pp 205If the destination is directly reachable 206via an interface requiring 207no intermediary system to act as a gateway, the 208.Fl interface 209modifier should be specified; 210the gateway given is the address of this host on the common network, 211indicating the interface to be used for transmission. 212Alternately, if the interface is point to point the name of the interface 213itself may be given, in which case the route remains valid even 214if the local or remote addresses change. 215.Pp 216The optional modifiers 217.Fl xns , 218.Fl osi , 219.Fl atalk , 220and 221.Fl link 222specify that all subsequent addresses are in the 223.Tn XNS , 224.Tn OSI , 225or 226.Tn AppleTalk 227address families, 228or are specified as link-level addresses, 229and the names must be numeric specifications rather than 230symbolic names. 231.Pp 232The optional 233.Fl netmask 234modifier is intended 235to achieve the effect of an 236.Tn OSI 237.Tn ESIS 238redirect with the netmask option, 239or to manually add subnet routes with 240netmasks different from that of the implied network interface 241(as would otherwise be communicated using the OSPF or ISIS routing protocols). 242One specifies an additional ensuing address parameter 243(to be interpreted as a network mask). 244The implicit network mask generated in the AF_INET case 245can be overridden by making sure this option follows the destination parameter. 246.Pp 247For 248.Dv AF_INET6 , 249the 250.Fl prefixlen 251qualifier 252is available instead of the 253.Fl mask 254qualifier because non-continuous masks are not allowed in IPv6. 255For example, 256.Fl prefixlen Li 32 257specifies network mask of 258.Li ffff:ffff:0000:0000:0000:0000:0000:0000 259to be used. 260The default value of prefixlen is 64 to get along with 261the aggregatable address. 262But 0 is assumed if 263.Cm default 264is specified. 265Note that the qualifier works only for 266.Dv AF_INET6 267address family. 268.Pp 269Routes have associated flags which influence operation of the protocols 270when sending to destinations matched by the routes. 271These flags may be set (or sometimes cleared) 272by indicating the following corresponding modifiers: 273.Bd -literal 274-cloning RTF_CLONING - generates a new route on use 275-xresolve RTF_XRESOLVE - emit mesg on use (for external lookup) 276-iface ~RTF_GATEWAY - destination is directly reachable 277-static RTF_STATIC - manually added route 278-nostatic ~RTF_STATIC - pretend route added by kernel or daemon 279-reject RTF_REJECT - emit an ICMP unreachable when matched 280-blackhole RTF_BLACKHOLE - silently discard pkts (during updates) 281-proto1 RTF_PROTO1 - set protocol specific routing flag #1 282-proto2 RTF_PROTO2 - set protocol specific routing flag #2 283-llinfo RTF_LLINFO - validly translates proto addr to link addr 284.Ed 285.Pp 286The optional modifiers 287.Fl rtt , 288.Fl rttvar , 289.Fl sendpipe , 290.Fl recvpipe , 291.Fl mtu , 292.Fl hopcount , 293.Fl expire , 294and 295.Fl ssthresh 296provide initial values to quantities maintained in the routing entry 297by transport level protocols, such as TCP or TP4. 298These may be individually locked by preceding each such modifier to 299be locked by 300the 301.Fl lock 302meta-modifier, or one can 303specify that all ensuing metrics may be locked by the 304.Fl lockrest 305meta-modifier. 306.Pp 307In a 308.Cm change 309or 310.Cm add 311command where the destination and gateway are not sufficient to specify 312the route (as in the 313.Tn ISO 314case where several interfaces may have the 315same address), the 316.Fl ifp 317or 318.Fl ifa 319modifiers may be used to determine the interface or interface address. 320.Pp 321The optional 322.Fl proxy 323modifier specifies that the 324.Dv RTF_LLINFO 325routing table entry is the 326.Dq published (proxy-only) 327.Tn ARP 328entry, as reported by 329.Xr arp 8 . 330.Pp 331All symbolic names specified for a 332.Ar destination 333or 334.Ar gateway 335are looked up first as a host name using 336.Xr gethostbyname 3 . 337If this lookup fails, 338.Xr getnetbyname 3 339is then used to interpret the name as that of a network. 340.Pp 341The 342.Nm 343utility uses a routing socket and the new message types 344.Dv RTM_ADD , RTM_DELETE , RTM_GET , 345and 346.Dv RTM_CHANGE . 347As such, only the super-user may modify 348the routing tables. 349.Sh DIAGNOSTICS 350.Bl -diag 351.It "add [host \&| network ] %s: gateway %s flags %x" 352The specified route is being added to the tables. The 353values printed are from the routing table entry supplied 354in the 355.Xr ioctl 2 356call. 357If the gateway address used was not the primary address of the gateway 358(the first one returned by 359.Xr gethostbyname 3 ) , 360the gateway address is printed numerically as well as symbolically. 361.It "delete [ host \&| network ] %s: gateway %s flags %x" 362As above, but when deleting an entry. 363.It "%s %s done" 364When the 365.Cm flush 366command is specified, each routing table entry deleted 367is indicated with a message of this form. 368.It "Network is unreachable" 369An attempt to add a route failed because the gateway listed was not 370on a directly-connected network. 371The next-hop gateway must be given. 372.It "not in table" 373A delete operation was attempted for an entry which 374wasn't present in the tables. 375.It "routing table overflow" 376An add operation was attempted, but the system was 377low on resources and was unable to allocate memory 378to create the new entry. 379.It "gateway uses the same route" 380A 381.Cm change 382operation resulted in a route whose gateway uses the 383same route as the one being changed. 384The next-hop gateway should be reachable through a different route. 385.El 386.Pp 387.Ex -std 388.Sh SEE ALSO 389.\".Xr esis 4 , 390.Xr netintro 4 , 391.Xr route 4 , 392.Xr arp 8 , 393.Xr IPXrouted 8 , 394.Xr routed 8 395.\".Xr XNSrouted 8 396.Sh HISTORY 397The 398.Nm 399utility appeared in 400.Bx 4.2 . 401.Sh BUGS 402The first paragraph may have slightly exaggerated 403.Xr routed 8 Ns 's 404abilities. 405