1 .\" Copyright (c) 1983, 1991, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
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. 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.
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
28 .\" @(#)route.8 8.3 (Berkeley) 3/19/94
29 .\" $FreeBSD: src/sbin/route/route.8,v 1.17.2.9 2003/02/24 00:56:43 trhodes Exp $
36 .Nd manually manipulate the routing tables
49 utility is used to manually manipulate the network
50 routing tables. It normally is not needed, as a
51 system routing table management daemon such as
53 should tend to this task.
57 utility supports a limited number of general options,
58 but a rich command language, enabling the user to specify
59 any arbitrary request that could be delivered via the
60 programmatic interface discussed in
63 The following options are available:
64 .Bl -tag -width indent
66 On SMP systems the route table is replicated. This option allows the
67 route table for a specific cpu to be accessed and exists primarily
68 for debugging purposes.
70 Bypass attempts to print host and network names symbolically
71 when reporting actions. (The process of translating between symbolic
72 names and numerical equivalents can be quite time consuming, and
73 may require correct operation of the network; thus it may be expedient
74 to forget this, especially when attempting to repair networking operations).
76 (verbose) Print additional details.
78 Suppress all output from the
84 Print the full width of the data being represented even if it would overflow
90 utility provides six commands:
92 .Bl -tag -width Fl -compact
98 Delete a specific route.
100 Change aspects of a route (such as its gateway).
102 Lookup and display the route for a destination.
104 Print out the route table similar to "netstat \-r" (see
107 Continuously report any changes to the routing information base,
108 routing lookup misses, or suspected network partitionings.
111 The monitor command has the syntax:
113 .Bd -ragged -offset indent -compact
119 The flush command has the syntax:
121 .Bd -ragged -offset indent -compact
130 command is specified,
132 will ``flush'' the routing tables of all gateway entries.
133 When the address family may is specified by any of the
137 modifiers, only routes having destinations with addresses in the
138 delineated family will be deleted.
140 The other commands have the following syntax:
142 .Bd -ragged -offset indent -compact
146 .Op Fl net No \&| Fl host
147 .Ar destination gateway
153 is the destination host or network,
155 is the next-hop intermediary via which packets should be routed.
156 Routes to a particular host may be distinguished from those to
157 a network by interpreting the Internet address specified as the
160 The optional modifiers
164 force the destination to be interpreted as a network or a host, respectively.
168 .Dq local address part
174 is the symbolic name of a network, then the route is
175 assumed to be to a network; otherwise, it is presumed to be a
179 could also be specified in the
180 .Ar net Ns / Ns Ar bits
186 .Fl host Li 128.0.0.32 ;
189 .Fl host Li 128.32.0.130 ;
193 .Fl net Li 128.32.130
199 .Fl net Li 192.168.64 Fl netmask Li 255.255.240.0 .
207 which is the default route.
209 If the destination is directly reachable
210 via an interface requiring
211 no intermediary system to act as a gateway, the
213 modifier should be specified;
214 the gateway given is the address of this host on the common network,
215 indicating the interface to be used for transmission.
216 Alternately, if the interface is point to point the name of the interface
217 itself may be given, in which case the route remains valid even
218 if the local or remote addresses change.
220 The optional modifiers
224 specify that all subsequent addresses are in the
227 or are specified as link-level addresses,
228 and the names must be numeric specifications rather than
233 modifier is intended to manually add subnet routes with
234 netmasks different from that of the implied network interface.
235 One specifies an additional ensuing address parameter
236 (to be interpreted as a network mask).
237 The implicit network mask generated in the AF_INET case
238 can be overridden by making sure this option follows the destination parameter.
245 is available instead of the
247 qualifier because non-continuous masks are not allowed in IPv6.
250 specifies network mask of
251 .Li ffff:ffff:0000:0000:0000:0000:0000:0000
253 The default value of prefixlen is 64 to get along with
254 the aggregatable address.
258 Note that the qualifier works only for
262 Routes have associated flags which influence operation of the protocols
263 when sending to destinations matched by the routes.
264 These flags may be set (or sometimes cleared)
265 by indicating the following corresponding modifiers:
267 -cloning RTF_CLONING - generates a new route on use
268 -xresolve RTF_XRESOLVE - emit mesg on use (for external lookup)
269 -iface ~RTF_GATEWAY - destination is directly reachable
270 -static RTF_STATIC - manually added route
271 -nostatic ~RTF_STATIC - pretend route added by kernel or daemon
272 -reject RTF_REJECT - emit an ICMP unreachable when matched
273 -blackhole RTF_BLACKHOLE - silently discard pkts (during updates)
274 -proto1 RTF_PROTO1 - set protocol specific routing flag #1
275 -proto2 RTF_PROTO2 - set protocol specific routing flag #2
276 -llinfo RTF_LLINFO - validly translates proto addr to link addr
279 The optional modifiers
292 provide initial values to quantities maintained in the routing entry
293 by transport level protocols, such as TCP or TP4.
294 These may be individually locked by preceding each such modifier to
298 meta-modifier, or one can
299 specify that all ensuing metrics may be locked by the
307 command where the destination and gateway are not sufficient to specify
310 case where several interfaces may have the
315 modifiers may be used to determine the interface or interface address.
319 modifier specifies that the
321 routing table entry is the
322 .Dq published (proxy-only)
324 entry, as reported by
327 All symbolic names specified for a
331 are looked up first as a host name using
332 .Xr gethostbyname 3 .
333 If this lookup fails,
335 is then used to interpret the name as that of a network.
342 modifiers may be used to specify the desired mpls label
343 operations for the route. Each route may have up to 3
344 label operations assigned to it. The label operations
345 may be combined between them, but specifically the
349 operations may be repeated if the intent is to push or pop
350 more than one label at once. The
352 operation always swaps the outer label and may not be
354 Here are some MPLS route examples:
356 Add an normal inet route, but push an mpls
360 .Bd -ragged -offset indent -compact
363 .Ar destination gateway
368 Add an normal inet route, but double-push an mpls
374 .Bd -ragged -offset indent -compact
377 .Ar destination gateway
384 Add an mpls route for an
388 and swap that label with
391 .Bd -ragged -offset indent -compact
404 utility uses a routing socket and the new message types
405 .Dv RTM_ADD , RTM_DELETE , RTM_GET ,
408 As such, only the super-user may modify
414 .It "add [host \&| network ] %s: gateway %s flags %x"
415 The specified route is being added to the tables. The
416 values printed are from the routing table entry supplied
420 If the gateway address used was not the primary address of the gateway
421 (the first one returned by
422 .Xr gethostbyname 3 ) ,
423 the gateway address is printed numerically as well as symbolically.
424 .It "delete [ host \&| network ] %s: gateway %s flags %x"
425 As above, but when deleting an entry.
429 command is specified, each routing table entry deleted
430 is indicated with a message of this form.
431 .It "Network is unreachable"
432 An attempt to add a route failed because the gateway listed was not
433 on a directly-connected network.
434 The next-hop gateway must be given.
436 A delete operation was attempted for an entry which
437 wasn't present in the tables.
438 .It "routing table overflow"
439 An add operation was attempted, but the system was
440 low on resources and was unable to allocate memory
441 to create the new entry.
442 .It "gateway uses the same route"
445 operation resulted in a route whose gateway uses the
446 same route as the one being changed.
447 The next-hop gateway should be reachable through a different route.
461 The first paragraph may have slightly exaggerated