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 t 75Run in test-only mode. 76.Pa /dev/null 77is used instead of a socket. 78.It Fl v 79(verbose) Print additional details. 80.It Fl q 81Suppress all output from the 82.Cm add , change , delete , 83and 84.Cm flush 85commands. 86.El 87.Pp 88The 89.Nm 90utility provides the following commands: 91.Pp 92.Bl -tag -width Fl -compact 93.It Cm add 94Add a route. 95.It Cm flush 96Remove all routes. 97.It Cm delete 98Delete a specific route. 99.It Cm del 100Another name for the 101.Cm delete 102command. 103.It Cm change 104Change aspects of a route (such as its gateway). 105.It Cm get 106Lookup and display the route for a destination. 107.It Cm monitor 108Continuously report any changes to the routing information base, 109routing lookup misses, or suspected network partitionings. 110.El 111.Pp 112The monitor command has the syntax: 113.Pp 114.Bd -ragged -offset indent -compact 115.Nm 116.Op Fl n 117.Cm monitor 118.Ed 119.Pp 120The flush command has the syntax: 121.Pp 122.Bd -ragged -offset indent -compact 123.Nm 124.Op Fl n 125.Cm flush 126.Op Ar family 127.Ed 128.Pp 129If the 130.Cm flush 131command is specified, 132.Nm 133will ``flush'' the routing tables of all gateway entries. 134When the address family may is specified by any of the 135.Fl osi , 136.Fl xns , 137.Fl atalk , 138.Fl inet6 , 139or 140.Fl inet 141modifiers, only routes having destinations with addresses in the 142delineated family will be deleted. 143.Pp 144The other commands have the following syntax: 145.Pp 146.Bd -ragged -offset indent -compact 147.Nm 148.Op Fl n 149.Ar command 150.Op Fl net No \&| Fl host 151.Ar destination gateway 152.Op Ar netmask 153.Ed 154.Pp 155where 156.Ar destination 157is the destination host or network, 158.Ar gateway 159is the next-hop intermediary via which packets should be routed. 160Routes to a particular host may be distinguished from those to 161a network by interpreting the Internet address specified as the 162.Ar destination 163argument. 164The optional modifiers 165.Fl net 166and 167.Fl host 168force the destination to be interpreted as a network or a host, respectively. 169Otherwise, if the 170.Ar destination 171has a 172.Dq local address part 173of 174INADDR_ANY 175.Pq Li 0.0.0.0 , 176or if the 177.Ar destination 178is the symbolic name of a network, then the route is 179assumed to be to a network; otherwise, it is presumed to be a 180route to a host. 181Optionally, the 182.Ar destination 183could also be specified in the 184.Ar net Ns / Ns Ar bits 185format. 186.Pp 187For example, 188.Li 128.32 189is interpreted as 190.Fl host Li 128.0.0.32 ; 191.Li 128.32.130 192is interpreted as 193.Fl host Li 128.32.0.130 ; 194.Fl net Li 128.32 195is interpreted as 196.Li 128.32.0.0; 197.Fl net Li 128.32.130 198is interpreted as 199.Li 128.32.130.0; 200and 201.Li 192.168.64/20 202is interpreted as 203.Fl net Li 192.168.64 Fl netmask Li 255.255.240.0 . 204.Pp 205A 206.Ar destination 207of 208.Ar default 209is a synonym for 210.Fl net Li 0.0.0.0 , 211which is the default route. 212.Pp 213If the destination is directly reachable 214via an interface requiring 215no intermediary system to act as a gateway, the 216.Fl interface 217modifier should be specified; 218the gateway given is the address of this host on the common network, 219indicating the interface to be used for transmission. 220Alternately, if the interface is point to point the name of the interface 221itself may be given, in which case the route remains valid even 222if the local or remote addresses change. 223.Pp 224The optional modifiers 225.Fl xns , 226.Fl osi , 227.Fl atalk , 228and 229.Fl link 230specify that all subsequent addresses are in the 231.Tn XNS , 232.Tn OSI , 233or 234.Tn AppleTalk 235address families, 236or are specified as link-level addresses, 237and the names must be numeric specifications rather than 238symbolic names. 239.Pp 240The optional 241.Fl netmask 242modifier is intended 243to achieve the effect of an 244.Tn OSI 245.Tn ESIS 246redirect with the netmask option, 247or to manually add subnet routes with 248netmasks different from that of the implied network interface 249(as would otherwise be communicated using the OSPF or ISIS routing protocols). 250One specifies an additional ensuing address parameter 251(to be interpreted as a network mask). 252The implicit network mask generated in the AF_INET case 253can be overridden by making sure this option follows the destination parameter. 254.Pp 255For 256.Dv AF_INET6 , 257the 258.Fl prefixlen 259qualifier 260is available instead of the 261.Fl mask 262qualifier because non-continuous masks are not allowed in IPv6. 263For example, 264.Fl prefixlen Li 32 265specifies network mask of 266.Li ffff:ffff:0000:0000:0000:0000:0000:0000 267to be used. 268The default value of prefixlen is 64 to get along with 269the aggregatable address. 270But 0 is assumed if 271.Cm default 272is specified. 273Note that the qualifier works only for 274.Dv AF_INET6 275address family. 276.Pp 277Routes have associated flags which influence operation of the protocols 278when sending to destinations matched by the routes. 279These flags may be set (or sometimes cleared) 280by indicating the following corresponding modifiers: 281.Bd -literal 282-cloning RTF_CLONING - generates a new route on use 283-xresolve RTF_XRESOLVE - emit mesg on use (for external lookup) 284-iface ~RTF_GATEWAY - destination is directly reachable 285-static RTF_STATIC - manually added route 286-nostatic ~RTF_STATIC - pretend route added by kernel or daemon 287-reject RTF_REJECT - emit an ICMP unreachable when matched 288-blackhole RTF_BLACKHOLE - silently discard pkts (during updates) 289-proto1 RTF_PROTO1 - set protocol specific routing flag #1 290-proto2 RTF_PROTO2 - set protocol specific routing flag #2 291-llinfo RTF_LLINFO - validly translates proto addr to link addr 292.Ed 293.Pp 294The optional modifiers 295.Fl rtt , 296.Fl rttvar , 297.Fl sendpipe , 298.Fl recvpipe , 299.Fl mtu , 300.Fl hopcount , 301.Fl expire , 302and 303.Fl ssthresh 304provide initial values to quantities maintained in the routing entry 305by transport level protocols, such as TCP or TP4. 306These may be individually locked by preceding each such modifier to 307be locked by 308the 309.Fl lock 310meta-modifier, or one can 311specify that all ensuing metrics may be locked by the 312.Fl lockrest 313meta-modifier. 314.Pp 315In a 316.Cm change 317or 318.Cm add 319command where the destination and gateway are not sufficient to specify 320the route (as in the 321.Tn ISO 322case where several interfaces may have the 323same address), the 324.Fl ifp 325or 326.Fl ifa 327modifiers may be used to determine the interface or interface address. 328.Pp 329The optional 330.Fl proxy 331modifier specifies that the 332.Dv RTF_LLINFO 333routing table entry is the 334.Dq published (proxy-only) 335.Tn ARP 336entry, as reported by 337.Xr arp 8 . 338.Pp 339The optional 340.Fl genmask 341modifier specifies that a cloning mask is present. 342This specifies the mask applied when determining if a child route 343should be created. 344It is only applicable to network routes with the 345.Dv RTF_CLONING 346flag set. 347.Pp 348All symbolic names specified for a 349.Ar destination 350or 351.Ar gateway 352are looked up first as a host name using 353.Xr gethostbyname 3 . 354If this lookup fails, 355.Xr getnetbyname 3 356is then used to interpret the name as that of a network. 357.Pp 358The 359.Nm 360utility uses a routing socket and the new message types 361.Dv RTM_ADD , RTM_DELETE , RTM_GET , 362and 363.Dv RTM_CHANGE . 364As such, only the super-user may modify 365the routing tables. 366.Sh EXIT STATUS 367.Ex -std 368.Sh DIAGNOSTICS 369.Bl -diag 370.It "add [host \&| network ] %s: gateway %s flags %x" 371The specified route is being added to the tables. 372The 373values printed are from the routing table entry supplied 374in the 375.Xr ioctl 2 376call. 377If the gateway address used was not the primary address of the gateway 378(the first one returned by 379.Xr gethostbyname 3 ) , 380the gateway address is printed numerically as well as symbolically. 381.It "delete [ host \&| network ] %s: gateway %s flags %x" 382As above, but when deleting an entry. 383.It "%s %s done" 384When the 385.Cm flush 386command is specified, each routing table entry deleted 387is indicated with a message of this form. 388.It "Network is unreachable" 389An attempt to add a route failed because the gateway listed was not 390on a directly-connected network. 391The next-hop gateway must be given. 392.It "not in table" 393A delete operation was attempted for an entry which 394was not present in the tables. 395.It "routing table overflow" 396An add operation was attempted, but the system was 397low on resources and was unable to allocate memory 398to create the new entry. 399.It "gateway uses the same route" 400A 401.Cm change 402operation resulted in a route whose gateway uses the 403same route as the one being changed. 404The next-hop gateway should be reachable through a different route. 405.El 406.Sh SEE ALSO 407.\".Xr esis 4 , 408.Xr netintro 4 , 409.Xr route 4 , 410.Xr arp 8 , 411.Xr IPXrouted 8 , 412.Xr routed 8 413.\".Xr XNSrouted 8 414.Sh HISTORY 415The 416.Nm 417utility appeared in 418.Bx 4.2 . 419.Sh BUGS 420The first paragraph may have slightly exaggerated 421.Xr routed 8 Ns 's 422abilities. 423.Pp 424Currently, routes with the 425.Dv RTF_BLACKHOLE 426flag set need to have the gateway set to an instance of the 427.Xr lo 4 428driver, using the 429.Fl iface 430option, for the flag to have any effect; unless IP fast forwarding 431is enabled, in which case the meaning of the flag will always 432be honored. 433