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: -all Specifies that the kernel add or delete the specified route on all interfaces (for example, tu0 and tu1) that are in the same subnet as the gateway. Use this modifier only with the add and delete modifiers. Do not use -all with the -dev and -olddev modifiers. -blackhole 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. -cloning Generates a new route on use of this route. -dev device 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. -genmask mask Specifies that the netmask mask is used for all routes cloned from this route. -hopcount count Sets this route's maximum hopcount to count. -iface | -interface Specifies that this route is via an interface instead of via a gateway (gateway is the default). This means the destination is reachable directly via an interface; no intermediate system is required. The gateway parameter is the address of this host on the common network, indicating the interface to be used for transmission. -inet Sets this route's type as AF_INET. When used with the delete or flush commands, only AF_INET routes are deleted. -inet6 Sets this route's type as AF_INET6. When used with the delete or flush commands, only AF_INET6 routes are deleted. -iso Sets this route's type as AF_ISO. When used with the delete or flush commands, only AF_ISO routes are deleted. -link Sets this route's type as AF_LINK. When used with the delete or flush commands, only AF_LINK routes are deleted. - Specifies that this route contains valid link-layer llinfo information. -lock Locks the metric set by next modifier specified on the command line in the routing entry. A locked metric is not modified by the kernel. The following metrics can be locked: mtu, hopcount, recvpipe, sendpipe, ssthresh, rtt, and rttvar. -lockrest Locks the metrics set by all modifiers that follow on the command line in the routing entry. A locked metric is not modified by the kernel. The following metrics can be locked: mtu, hopcount, recvpipe, sendpipe, ssthresh, rtt, and rttvar. -mtu size Sets this route's maximum transmission unit (MTU), in bytes, to size. -netmask mask 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. -nofragtopmtu Specifies that fragment to path MTU size is disabled for this route. -nopmtudisc Specifies that path MTU discovery is disabled for this route. -olddev device 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. -oldgateway name 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. -oldinterface Specifies the old interface in the routing entry that you want to change. Use this modifier with the change command only. -osi Sets this route's type as AF_ISO. When used with the delete or flush commands, only AF_ISO routes are deleted. -precedence value Sets the precedence of the route to value. Among equivalent routes to the same destination, the route with the lower precedence is preferred. -recvpipe bandwidth Sets this route's inbound delay bandwidth product (in bytes) to bandwidth. - Specifies that this route is a reject route. Packets reject 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. -rtt time Sets this route's round trip time (in microseconds) to time. -rttvar variance Sets this route's round trip time variance (in microseconds) to variance. -sendpipe bandwidth Sets this route's outbound delay bandwidth product (in bytes) to bandwidth. -ssthresh threshold Sets this route's outbound gateway buffer limit (in bytes) to threshold.