Purpose

The Add TCP/IP Route (ADDTCPRTE) command is used to identify a route to a remote network or a route to a remote destination system in the Transmission Control Protocol/Internet Protocol (TCP/IP) configuration.

Five parameter values uniquely define a route. These values are the route destination (RTEDEST), the subnet mask (SUBNETMASK), the type of service (TOS), the internet address of the next system on the route (NEXTHOP) and the preferred binding interface (BINDIFC). For default routes and default multicast routes (*DFTROUTE and *DFTMCAST), the NEXTHOP, TOS and BINDIFC values uniquely define the route because the SUBNETMASK is always *NONE.

Additionally, parameters will be added that will allow the specification of that route's Metric or Cost of Use (METRIC), the specification of how this route will be shown to other routers (REDST) and this route's Precedence when duplicates of this same route are contained within the routing table (DUPRTEPTY). These parameters are required in support of the RIP, Version 4 Release 2, Routing Protocol.

Restrictions:

1. You must have *IOSYSCFG special authority to use this command.

2. A route cannot be added unless the internet address specified by the NEXTHOP parameter can be reached directly through a network associated with a previously defined TCP/IP interface. An interface can be added using the ADDTCPIFC command.

3. A route destination value of 127.nnn.nnn.nnn (where nnn is any value from 0 to 255) is not allowed. It is a reserved value for *LOOPBACK.

Required Parameters

RTEDEST Specifies the route destination being added. You must specify all 4 bytes that make up an internet address though some of the bytes may be equal to 0. For example, a route to all the hosts on the 9.5.11 subnetwork is identified by entering 9.5.11.0 for the route destination. Used in combination with a subnetmask, type of service value, and next hop, the route destination uniquely identifies a route to a network or system.

*DFTROUTE: Specifies that a default route entry is being added. A default route entry is used by the system to route data that is being sent to a remote destination that does not have a specific route defined. The system allows a maximum of 8 default route entries. The default route entries are used based on the availability of the next hop gateway and the type of service (TOS). If the application requests a specific TOS, the TOS of the default route used must match the TOS requested. If no default route is found that matches the requested TOS, the first available default route with a TOS of *NORMAL is used.

*DFTMCAST: Specifies that a default multicast route entry is being added. A default multicast route entry is used by the system to select a local interface when sending data to a multicast group. The default multicast entry is used when the application does not specifically name the local interface over which multicast packets should be sent. When RTEDEST(*DFTMCAST) is specified, SUBNETMASK(*NONE) must be specified and the NEXTHOP parameter must be the internet address of an interface that had previously been added with the Add TCP/IP Interface (ADDTCPIFC) command.

route-destination: Specify the route destination being added. The route destination can be specified in the form nnn.0.0.0, for Class A, nnn.nnn.0.0 for Class B, and nnn.nnn.nnn.0 for Class C, or nnn.nnn.nnn.nnn for any combination thereof, where nnn is a decimal number ranging from 0 through 255.

Any combination thereof means that you may specify a route, such as 9.5.0.0 to the hosts on the 9.5 subnet, even though all 9.5.x.x addresses are class A network addresses.

Exceptions:

° The first byte (octet) must be greater than 0 and less than 255. ° The last byte (octet) may not equal 255. ° The last byte (octet) may not equal 0 if *HOST is specified for the SUBNETMASK value. ° Routes to a broadcast address are not allowed.

SUBNETMASK Specifies a bit mask that identifies to TCP/IP which bits of the value specified for the route destination (RTEDEST) compose the network and subnet portions of the internet address. By defining the network portion and subnetwork portion of the RTEDEST address, the subnet mask also defines which bits of the RTEDEST address make up the host portion. The mask is a 32-bit combination that is logically ANDed with the internet address to determine a particular subnetwork. The bits of the mask set to the value one (1) determine the network and subnetwork portions of the address. The bits set to the value zero (0) determine the host portion of the address.

*NONE: There is no subnet mask. If RTEDEST(*DFTROUTE) or RTEDEST(*DFTMCAST) is specified, SUBNETMASK(*NONE) must be specified. *NONE is valid only for the *DFTROUTE and *DFTMCAST route destination values.

*HOST: The internet address value specified in the route destination field is a host address. The subnetmask value is calculated to be 255.255.255.255.

subnet-mask: Specify the mask of the subnet field. The internet address is in the form nnn.nnn.nnn.nnn where nnn is a decimal number ranging from 0 through 255. For example, a destination route's internet address value of 129.35.192.0 identifies a Class B subnetwork. The network ID part of its address is 129.35. The portion of the subnetmask that is associated with the network portion of a particular class of address must equal 255. Therefore, the upper 2 bytes must be equal to 255.255 in the subnetmask. The subnetmask in this example may be 255.255.192.0 if the third octet is used as the subnetwork ID portion of the internet address.

TOS Specifies the type of service to be used. The type of service defines how the internet hosts and routers should make trade-offs between throughput, delay, reliability, and cost.

*NORMAL: Normal service is used for delivery of data.

*MINDELAY: Minimize delay means that prompt delivery is important for data on this connection.

*MAXTHRPUT: Maximize throughput means that a high data rate is important for data on this connection.

*MAXRLB: Maximize reliability means that a higher level of effort to ensure delivery is important for data on this connection.

*MINCOST: Minimize monetary cost means that lower cost is important for data on this connection.

NEXTHOP Specifies the internet address of the next system (gateway) on the route. A route cannot be added unless the internet address specified by the NEXTHOP parameter can be reached directly through a network associated with a previously defined TCP/IP interface. An interface can be added by using the Add TCP/IP Interface (ADDTCPIFC) command. An interface can be added by using the Add TCP/IP Interface (ADDTCPIFC) command.

*HOME is no longer supported for route specifications to define a direct route generated from a previously defined interface.

internet-address: Specify the internet address. The internet address is specified in the form nnn.nnn.nnn.nnn, where nnn is a decimal number ranging from 0 through 255. An internet address is not valid if it has a value of all binary ones or all binary zeros for the network identifier (ID) portion or the host ID portion of the address. If the internet address is entered from a command line, the address must be enclosed in apostrophes.

| BINDIFC
| The local IP interface to bind this route to. The binding is preferred
| and not absolute.

| If the IP interface defined for BINDIFC is active, then the route
| specified is bound to that interface. If the IP interface defined for
| BINDIFC is not active, then another active IP interface using the same
| line description is used. If the IP interface defined for BINDIFC is
| not active and no other interfaces using the same line description are
| active, then any active interface on the same network will be used. If
| no IP interfaces on the same network are available, then the route
| will be disabled.

| *NONE: TCP/IP will not attempt to bind this route to a particular IP
| interface but will bind it to the first active IP interface on the
| network as defined by the NEXTHOP and SUBNETMASK parameters.

| binding-interface: Specify an IP interface to bind this route to. The
| binding is preferred and not absolute.

Optional Parameters

MTU Specifies the maximum size (in bytes) of IP datagrams that can be transmitted through this route. A datagram is a basic unit of information passed over an internet network. The minimum size of any maximum transmission unit value is 576 bytes.

576: The maximum transmission unit (MTU) is 576 bytes. This is the default.

*IFC: The maximum transmission unit (MTU) is the MTU of the interface that is associated with this route.

maximum-transmission-unit: Specify a value for the maximum transmission unit in bytes. The maximum MTU that can be specified for this route depends on the type of physical connection to the network. The following table lists the maximum MTU values that can be specified based on the line type:

X.25 4096 Token ring (4 meg) 4060 Token ring (16 meg) 16388 Ethernet 802.3 1492 Ethernet Version 2 1500 DDI 4352 Frame relay 8177 Wireless 802.3 1492 Wireless Version 2 1500

Notes:

1. TCP/IP uses the route MTU value to calculate the size of the datagrams it sends. For best performance, specify a value that is no smaller than the smallest MTU used by host systems along the entire path of this route. If this information is not available, use the default value of 576.

2. The MTU of a route cannot exceed the MTU of the interface on which the NEXTHOP value is accessed. If the interface's MTU value was specified as *LIND, the interface's MTU value is derived from the line description. If the route's MTU value is specified as *IFC and the interface's MTU value is specified as *LIND, both values are derived from the line description.

3. The actual MTU value used for a route is resolved during interface activation. This value is the minimum of either the specified MTU value for the route or the MTU value determined from the associated interface used by the route.

METRIC Specifies the cost associated with the use of this route. A value of 1 is a route that is close (nearby), whereas a route with a value of 15 is relatively far away. A route with a Metric of 16 is considered to be unreachable (infinitely far away).

1: The route metric is set to 1.

metric-value: Specify a metric value. Valid metric values range from 1 to 16.

REDST Specifies whether this statically-defined route is to be redistributed (made available to other routers) in the future.

*YES: Specifies that this route will be shown (redistributed) to other routers. This is the default.

*NO: Specifies that this route will not be shown (redistributed) to other routers.

Note: REDST(*YES) is analogous to the RIPv1 specification of STATIC. REDST(*NO) is analogous to the RIPv1 specification of PASSIVE.

DUPRTEPTY The duplicate route priority value allows for ordering of duplicate routes within an internal route table. It allows specification of which particular duplicate route should be tried first in cases where a route cannot establish a connection.

5: Specifies a priority value of 5 for this route.

priority-value: Specify a priority value. Valid values are in the range of 1 to 10.

Note: Higher priority values will allow a route to be chosen over a route that specifies a lower priority. The default value of 5 is essentially a "middle of the road" priority value allowing the user to lower or raise the value from this starting point.

Examples

Example 1: Adding a Route

ADDTCPRTE RTEDEST('132.65.8.0') SUBNETMASK('255.255.255.0') TOS(*MINDELAY) NEXTHOP('148.92.6.40') MTU(*IFC) METRIC('3') REDST(*NO)

This command specifies the following for this route:

° A route destination of a class B network.

° Subnetting through the third octet.

° A minimum delay type of service for the interface.

° This route is connected to or can be reached by going through a gateway identified as 148.92.6.40.

° The maximum transmission unit (MTU) is to be calculated based on the interface associated with the next hop for this route.

° The route has a metric or cost of use of 3.

° This route will not be redistributed or shown to other routers.

Example 2: Adding a Route with a Specific MTU

ADDTCPRTE RTEDEST('9.10.45.0') SUBNETMASK('255.255.255.0') TOS(*MAXRLB) NEXTHOP('9.5.11.128') MTU(1994)

This command specifies the following for this route:

° A route destination of a class A network.

° Subnetting through the third octet.

° A maximum reliability type of service for the interface.

° This route is connected to or can be reached by going through a gateway identified as 9.5.11.128.

° A maximum transmission unit (MTU) of 1994.

Example 3: Adding a Default Route

ADDTCPRTE RTEDEST(*DFTROUTE) SUBNETMASK(*NONE) TOS(*MINCOST) NEXTHOP('186.49.126.108') MTU(*IFC)

ADDTCPRTE RTEDEST(*DFTROUTE) SUBNETMASK(*NONE) TOS(*NORMAL) NEXTHOP('129.65.34.98') MTU(576)

These commands specify that:

° Two default routes are used for this host.

° Data may be routed over either default route.

° Processing will use the first *DFTROUTE specified that also has the same type of service requested by the application.

° Minimum cost (*MINCOST) type of service is used for the first route and normal (*NORMAL) type of service is used for the second route.

° A maximum transmission unit (MTU) of *IFC is used for the first route and 576 for the second route.

Note: You cannot specify a subnetmask on a default route entry. It must equal *NONE.