Content-type: text/html Man page of route

route

Section: Maintenance Commands (8)
Index Return to Main Contents
 

NAME

route - Manipulates the routing tables manually  

SYNOPSIS

 

Adding a Route

route [-nqvC] add [-net|-host]
  destination[/bitmask] gateway [modifiers [args]]
 

Changing a Route

route [-nqv] change [-net|-host]
  destination gateway [modifiers [args]]
 

Monitoring a Route

route [-n] monitor
 

Deleting a Route

route [-nqvC] delete [-net|-host]
  destination[/bitmask] gateway [modifiers [args]]
 

Deleting All Routes

route [-nqvC] flush [-inet]
 

FLAGS

Prints host and network names in numeric format, instead of symbolic format, when reporting actions. Suppresses all output. Causes additional details to be printed. Forces route to use the old ioctl calls instead of the current route server request path.  

PARAMETERS

Specifies explicitly that this route is a network route; destination is interpreted as a network address. Specifies explicitly that this route is a host route; destination is interpreted as a host address. Specifies the destination host or network (with or without the optional Classless Inter-Domain Routing (CIDR) mask (/bitmask)). Specifies the next hop and gateway to which packets should be addressed.  

DESCRIPTION

The route command is a program used to manually manipulate the network routing tables. It normally is not needed, as a system routing table management daemon, such as gated or routed, should tend to this task.

The route command accepts five commands: Adds a route. Removes all gateway entries from the routing tables. You can choose to flush only those routes whose destinations are of a given address family by specifying an optional keyword describing which address family. Deletes a specific route. Changes aspects of a route (such as its gateway). Reports any changes to the routing information base, routing lookup misses, or suspected network partionings.

Unless the -net or -host parameters are specified on the command line, route creates a host route or a network route by interpreting the Internet address associated with destination parameter. If the destination has a local address part of INADDR_ANY, or if the destination is the symbolic name of a network, a network route is created; otherwise, a host route is created.

For example, 128.32 is interpreted as -host 128.0.0.32, 128.32.130 is interpreted as -host 128.32.0.130; -net 128.32 is interpreted as 128.32.0.0, and -net 128.32.130 is interpreted as 128.32.130.0.

All symbolic names specified for a destination or gateway are looked up first as a hostname using gethostbyname(3). If this lookup fails, getnetbyname(3) is then used to interpret the name as that of a network.

Routes added with the route command are marked as RTF_STATIC to differentiate them from routes added by the routing daemons (gated or routed). The gated daemon does not remove the RTF_STATIC routes when it is shut down.

The route command uses a routing socket and the new message types RTM_ADD, RTM_DELETE, and RTM_CHANGE.  

Modifiers

Modifiers provide initial values to metrics and other information maintained in the routing entry. All modifiers and their arguments are optional and must appear after the gateway field on the command line. The modifiers for the add, change, and delete commands are as follows: Specifies that this route is a blackhole route. Packets sent to blackhole routes are dropped, and no notification is sent to the packet originators. This is different from a normal route, which allows packets to be forwarded out on it. You must specify 127.0.0.1 (localhost) as the gateway argument. Generates a new route on use of this route. Specifies the interface device (for example, tu0 and fta0) to use in the routing entry. Use this modifier when you want to designate a particular interface for a route. If you do not specify this modifier, the route is added on the first interface that is found. Specifies that the netmask mask is used for all routes cloned from this route. Sets this route's maximum hopcount to count. Specifies that this route is via an interface instead of via a gateway (the default). This means the destination is reachable directly via an interface; no intermediate system is required to act as a gateway. The gateway parameter is the address of this host on the common network, indicating the interface to be used for transmission. Sets this route's type as AF_INET. When used with the delete or flush commands, only AF_INET routes are deleted. Sets this route's type as AF_ISO. When used with the delete or flush commands, only AF_ISO routes are deleted. Sets this route's type as AF_LINK. When used with the delete or flush commands, only AF_LINK routes are deleted. Locks the metric set by next modifier specified on the command line in the routing entry. The following metrics can be locked: mtu, hopcount, recvpipe, sendpipe, ssthresh, rtt, and rttvar. Locks the metrics set by all modifiers that follow on the command line in the routing entry. The following metrics can be locked: mtu, hopcount, recvpipe, sendpipe, ssthresh, rtt, and rttvar. Sets this route's maximum transmission unit (MTU), in bytes, to size. Specifies the subnet mask to use for the routing entry. Networks that use a nonstandard subnet must include this modifier. Specify this modifier after any optional modifiers. Do not specify this modifier if you specify a CIDR bitmask (/bitmask). Do not specify this modifier with the change command. Specifies the old interface device (for example, tu0 and fta0) in the routing entry that you want to change. Use this modifier with the change command only to move a route from one interface to another. See the "Examples" section. Specifies the old gateway in the routing entry that you want to change. Use this modifier with the change command only. See the "Examples" section. Sets this route's type as AF_ISO. When used with the delete or flush commands, only AF_ISO routes are deleted. Sets this route's inbound delay bandwidth product (in bytes) to bandwidth. Specifies that this route is a reject route. Packets sent to reject routes are dropped and messages designating the route as unreachable are sent to the packet originators. This is different from a normal route, which allows packets to be forwarded out on it. You must specify 127.0.0.1 (localhost) as the gateway argument. Sets this route's round trip time (in microseconds) to time. Sets this route's round trip time variance (in microseconds) to variance. Sets this route's outbound delay bandwidth product (in bytes) to bandwidth. Sets this route's outbound gateway buffer limit (in bytes) to threshold.  

RESTRICTIONS

You must be superuser in order to run the route command and to modify the routing tables.  

EXAMPLES

To add gateway 128.32.0.130 as a default gateway, enter: route add default 128.32.0.130 To add a route to host milan via gateway 128.32.0.130, enter: route add -host milan 128.32.0.130 To delete an existing route via gateway 128.32.0.130 to host milan, enter: route delete -host milan 128.32.0.130 To add a route to network 212.232.32 via gateway 128.32.0.130, enter: route add -net 212.232.32/22 128.32.0.130 The previous example aggregates routes for four Class C networks: 212.232.32, 212.232.33, 212.232.34, and 212.232.35. To add a route to network 212.232.32/22 via gateway 128.32.0.130 and lock the MTU size at 1500, enter: route add -net 197.45.63/24 214.89.32.235 -lock -mtu 1500 To add a route to network 212.232.32/22 via gateway 128.32.0.130 and lock the MTU size and hop count, enter: route add -net 197.45.63/24 214.89.32.235 -lockrest -mtu 1500 \ -hopcount 2 To change existing network route 206.98.17 via gateway 206.98.17.45 from using interface device tu0 to tu1, enter: route change -net 206.98.17 206.98.17.45 -olddev tu0 -dev tu1 This assumes that interface device tu1 is configured with an IP address in the same subnet as tu0. To change existing network route 206.98.17 from using gateway 206.98.17.45 to 206.98.17.162, enter: route change -net 206.98.17 206.98.17.162 -oldgateway 206.98.17.45 To change existing network route 206.98.17 using interface device tu0 and gateway 206.98.17.45 to use device tu1 and gateway 206.98.17.162, enter: route change -net 206.98.17 206.98.17.162 -olddev tu0 -dev tu1 \ -oldgateway 206.98.17.45 To add a route to host 219.67.129.16 via gateway 219.67.122.41 using interface device tu1, enter: route add -host 219.67.129.16 219.67.122.41 -dev tu1 To delete a route to network 219.84.6 via gateway 219.84.6.79 using interface device fta0, enter: route delete -net 219.84.6 219.84.6.79 -olddev fta0  

DIAGNOSTICS

The specified route is being added to the tables. If the gateway address used was not the primary address of the gateway (the first one returned by gethostbyname), the gateway address is printed numerically as well as symbolically. The optional /bitmask parameter was specified with the change command. Do not specify a bit mask with the change command. The specified route is being deleted from the tables. If the gateway address used was not the primary address of the gateway (the first one returned by gethostbyname), the gateway address is printed numerically as well as symbolically. When you use the flush command, each routing table entry deleted is indicated with a message of this form. An add operation was attempted for an entry that already exists in the routing tables. The gateway value is incorrect for creating reject and blackhole routes. The bitmask specified is not in the range of 1 to 32, inclusive. The -netmask modifier was specified together with a CIDR bit mask. The optional -netmask modifier was specified with the change command. Do not specify a network mask with the change command. An attempt to add a route failed because the gateway listed was not on a directly connected network. The next hop gateway must be given. A delete operation was attempted for an entry that was not present in the tables. An add operation was attempted, but the system was low on resources and was unable to allocate memory to create the new entry.  

FILES

Specifies the command path  

RELATED INFORMATION

Commands: netstat(1), gated(8), routed(8).

Networking: netintro(7). delim off


 

Index

NAME
SYNOPSIS
Adding a Route
Changing a Route
Monitoring a Route
Deleting a Route
Deleting All Routes
FLAGS
PARAMETERS
DESCRIPTION
Modifiers
RESTRICTIONS
EXAMPLES
DIAGNOSTICS
FILES
RELATED INFORMATION

This document was created by man2html, using the manual pages.
Time: 02:40:34 GMT, October 02, 2010