route
NAME
route - manually manipulate the routing tablesSYNOPSIS
route [ -fnvq ] command [ [ modifiers ] args ] route [ -fnvq ] add | delete [ modifiers ] destination gateway [ args ] route [ -fnvq ] change | get [ modifiers ] destination [ gateway [ args ] ] route [ -n ] monitor [ modifiers ] route [ -n ] flush [ modifiers ]DESCRIPTION
route manually manipulates the network routing tables. These tables are normally maintained by the system routing daemon, such as in.routed(1M) and in.ripngd(1M). This utility supports a limited number of general options, but a rich command language. It enables the user to specify any arbitrary request that could be delivered by means of the programmatic interface discussed in route(7P). route uses a routing socket and the new message types RTM_ADD, RTM_DELETE, RTM_GET, and RTM_CHANGE. As such, only the superuser may modify the routing tables.OPTIONS
-f Flush the routing tables of all gateway entries. If this is used in conjunction with one of the commands described above, route flushes the gateways before performing the command. -n Prevent attempts to print host and network names sym- bolically when reporting actions. This is useful, for example, when all name servers are down on your local net, and you need a route before you can contact the name server. -v (Verbose) Print additional details. -q Suppress all output.Commands
route executes one of four commands on a route to a destina- tion. Two additional commands operate globally on all rout- ing information. The six commands are: add Add a route. change Change aspects of a route (such as its gateway). delete Delete a specific route. flush Remove all gateway entries from the routing table. get Lookup and display the route for a destination. monitor Continuously report any changes to the routing infor- mation base, routing lookup misses, or suspected net- work partitionings. The add, delete, and change commands have the following syn- tax: route [ -fnvq ] add | delete [ -net | -host ] destination gateway [args] or route [ -fnvq ] change | get [ -net | -host ] destination gateway [args] where destination is the destination host or network, and gateway is the next-hop intermediary through which packets should be routed.OPERANDS
route executes its commands on routes to destinations.Destinations
By default, a destination is looked up under the AF_INET address family or as an IPv4 address. All symbolic names specified for a destination or gateway are looked up first as a host name, using getipnodebyname(3SOCKET). If this lookup fails in the AF_INET case, getnetbyname(3SOCKET) is used to interpret the name as that of a network. An optional modifier may be included on the command line before a destination, to force how route interprets a desti- nation: -host Forces the destination to be interpreted as a host. -net Forces the destination to be interpreted as a network. -inet Forces the destination to be interpreted under the AF_INET address family or as an IPv4 address. -inet6 Forces the destination to be interpreted under the AF_INET6 address family or as an IPv6 address. In the case of the AF_INET address family or an IPv4 address, routes to a particular host may be distinguished from those to a network by interpreting the Internet address specified as the destination. If the destination has a "local address part" of INADDR_ANY, or if the destination is the symbolic name of a network, then the route is assumed to be to a network; otherwise, it is presumed to be a route to a host. For example: The following route: Is interpreted as: 128.32 -host 128.0.0.32 128.32.130 -host 128.32.0.130 -net 128.32 128.32.0.0 -net 128.32.130 128.32.130.0 If the destination is directly reachable by way of an inter- face requiring no intermediary system to act as a gateway, this can be indicated by including one of two optional modifiers after the destination: The -interface modifier can be included or a metric of 0 can be specified. These modif- iers are illustrated in the following alternative examples: example% route add default hostname -interface example% route add default hostname 0 hostname is the name or IP address associated with the net- work interface all packets should be sent over. On a host with a single network interface, hostname is normally the same as the nodename returned by uname -n (see uname(1)). In the above examples, the route does not refer to a gate- way, but rather to one of the machine's interfaces. Desti- nations matching such a route are sent out on the interface identified by the gateway address. For interfaces using the ARP protocol, this type of route is used to specify all des- tinations are local. That is, a host should ARP for all addresses by adding a default route using one of the two commands listed above. With the AF_INET address family or an IPv4 address, the optional -netmask qualifier is intended to manually add sub- net routes with netmasks different from that of the implied network interface. The implicit network mask generated in the AF_INET case can be overridden by making sure this option, and an ensuing address parameter (to be interpreted as a network mask), follows the destination parameter. Alternatively, the length of the netmask may be supplied by appending a slash character and the length immediately after the destination. For example: example% route add 192.0.2.32/27 somegateway will create an IPv4 route to the destination 192.0.2.32 with a netmask of 255.255.255.224, and example% route add -inet6 3ffe::/16 somegateway will create an IPv6 route to the destination 33fe:: with a netmask of 16 one-bits followed by 112 zero-bits.Routing Flags
Routes have associated flags which influence operation of the protocols when sending to destinations matched by the routes. These flags may be set (or sometimes cleared) by including the following corresponding modifiers on the com- mand line: Modifier Flag Description -cloning RTF_CLONING generates a new route on use -xresolve RTF_XRESOLVE emit mesg on use (for external lookup) -iface ~RTF_GATEWAY destination is directly reachable -static RTF_STATIC manually added route -nostatic ~RTF_STATIC pretend route added by kernel or daemon -reject RTF_REJECT emit an ICMP unreachable when matched -blackhole RTF_BLACKHOLE silently discard pkts (during updates) -proto1 RTF_PROTO1 set protocol specific routing flag #1 -proto2 RTF_PROTO2 set protocol specific routing flag #2 -private RTF_PRIVATE do not adveritse this route The optional modifiers -rtt, -rttvar, -sendpipe, -recvpipe, -mtu, -hopcount, -expire, and -ssthresh provide initial values to quantities maintained in the routing entry by transport level protocols, such as TCP. These may be individually locked either by preceding each modifier to be locked by the -lock meta-modifier, or by specifying that all ensuing metrics may be locked by the -lockrest meta-modifier. The optional modifiers are defined as follows: -expire Lifetime for the entry. This optional modifier is not currently supported. -hopcount Maximum hop count. This optional modifier is not currently supported. -mtu Maximum MTU in bytes. -recvpipe Receive pipe size in bytes. -rtt Round trip time in microseconds. -rttvar Round trip time variance in microseconds. -sendpipe Send pipe size in bytes. -ssthresh Send pipe size threshold in bytes. Some transport layer protocols may support only some of these metrics. In a change or add command where the destination and gateway are not sufficient to specify the route (for example, , when several interfaces have the same address), the -ifp or -ifa modifiers may be used to determine the interface or inter- face address.FILES
/etc/hosts" list of host names and net addresses /etc/networks" list of network names and addressesATTRIBUTES
See attributes(5) for descriptions of the following attri- butes: ____________________________________________________________ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | |_____________________________|_____________________________| | Availability | SUNWcsu | |_____________________________|_____________________________|SEE ALSO
get(1), uname(1), in.rdisc(1M), netstat(1M), routed(1M), ioctl(2), getipnodebyname(3SOCKET), getnetbyname(3SOCKET), hosts(4), network(4), attributes(5), ARP(7P), route(7P), routing(7P)DIAGNOSTICS
add [ host| network] destination:gateway flags The specified route is being added to the tables. The values printed are from the routing table entry sup- plied in the ioctl(2) call. If the gateway address used was not the primary address of the gateway (the first one returned by getipnodebyname(3SOCKET)) the gateway address is printed numerically as well as sym- bolically. delete [ host| network] destination:gateway flags As above, but when deleting an entry. destination done When the -f flag is specified, or in the flush com- mand, each routing table entry deleted is indicated with a message of this form. Network is unreachable An attempt to add a route failed because the gateway listed was not on a directly-connected network. Give the next-hop gateway instead. not in table A delete operation was attempted for an entry that is not in the table. routing table overflow An add operation was attempted, but the system was unable to allocate memory to create the new entry.NOTES
All destinations are local assumes that the routers imple- ment the protocol, proxy arp. Normally, using router discovery (see in.rdisc(1M)) is more reliable than using proxy arp. Combining the all destinations are local route with subnet or network routes can lead to unpredictable results: the search order as it relates to the all destinations are local route are undefined and may vary from release to release. SunOS 5.8 Last change: 8 Nov 1999 7