Add TCP/IP Route (ADDTCPRTE)
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).
Restrictions:
- You must have input/output system configuration (*IOSYSCFG) special authority to run this command.
- 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.
- 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.
| Keyword |
Description |
Choices |
Notes |
| RTEDEST |
Route destination |
Character value, *DFTROUTE, *DFTMCAST |
Required, Positional 1 |
| SUBNETMASK |
Subnet mask |
Character value, *NONE, *HOST |
Required, Positional 2 |
| TOS |
Type of service |
*MINDELAY, *MAXTHRPUT, *MAXRLB, *MINCOST, *NORMAL |
Optional, Positional 3 |
| NEXTHOP |
Next hop |
Character value |
Optional |
| BINDIFC |
Preferred binding interface |
Character value, *NONE |
Optional |
| MTU |
Maximum transmission unit |
576-16388, *IFC |
Optional |
| METRIC |
Route metric |
1-16, 1 |
Optional |
| REDST |
Route redistribution |
*NO, *YES |
Optional |
| DUPRTEPTY |
Duplicate route priority |
1-10, 5 |
Optional |
Route destination (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 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
- Use the *DFTMCAST special value to indicate that the static route you are adding is a default Multicast route. The default Multicast route is used by an application when no specific route is specified.
Note: When RTEDEST(*DFTMCAST) is specified, then SUBNETMASK(*NONE) must also be specified and the NEXTHOP parameter must be a local TCP/IP interface (on this system).
- 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.
Subnet mask (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
- No subnet mask is used. A subnet mask is not used when specifying default routes. For example, when RTEDEST(*DFTMCAST) or RTEDEST(*DFTROUTE) is specified, SUBNETMASK(*NONE) must also be specified.
- *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.
Type of service (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.
Next hop (NEXTHOP)
Specifies the internet address of the next system (router) 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.
Note: *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.
Note: If you are adding a *DFTMCAST (default Multicast route) the *NEXTHOP internet address must be local, on this system, and not one hop away.
Preferred binding interface (BINDIFC)
Specifies the IP interface this route will be bound to. The bind is absolute.
Note: This parameter is useful only when there are multiple interfaces defined on your system for the same network. BINDIFC allows you to define which interface should be used to reach the network for a particular route destination. In this way you can distribute traffic (load balancing) across multiple interfaces so all routes do not use the same interface to reach the network.
If the IP interface you specify is active, this route will bind to it, otherwise it will follow the normal route binding rules (which are also used when BINDIFC is defined as *NONE).
- *NONE
- No particular IP interface will be bound to this route. The first active IP interface on the network defined by the NEXTHOP and SUBNETMASK parameters will be used. This is the default value.
- character-value
- Specify the internet address (IP address) of the interface you want this route to bind to. The binding is preferred and absolute.
Maximum transmission unit (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.
- *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
- Twinax (TDLC)
- 4105
Notes:
- TCP/IP uses the route MTU value to calculate the size of the datagrams it sends. If you are using path MTU discovery, specify MTU(*IFC). This will allow the TCP/IP support to calculate the most efficient MTU for this route. If you are not using path MTU discovery, and you do not know the smallest MTU used by host systems along the entire path of this route, use 576.
- 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.
- 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.
Route metric (METRIC)
Allows you to assign a routing metric "cost" value to this route. The metric cost of a route is a factor in determining the desirability of the route. The metric value range is from 1 to 16. A metric value of 1 is close (one router hop) and therefore desirable. Desirability decreases as the metric value (distance) increases. A metric value of 16 is considered unreachable (an infinite distance away).
You can discourage the routing table from choosing this route by specifying a metric value that is higher than the actual number of hops to the destination and therefore reduce traffic on this route.
- 1
- A routing metric cost value of 1 is used.
- 1-16
- Specify the metric value to be used.
Route redistribution (REDST)
Specifies whether this static route information will be shared with other routers. You can reduce traffic on this route by specifying *NO.
- *NO
- This route will not be shown or shared with other routers.
- *YES
- This route will be shown to any requesting router.
Note: REDST(*YES) is analogous to the RIPv1 specification of STATIC. REDST(*NO) is analogous to the RIPv1 specification of PASSIVE.
Duplicate route priority (DUPRTEPTY)
Specify the duplicate route priority of this static route. The values allowed for this parameter are 1 (lowest priority) to 10 (highest priority).
- 5
- A duplicate route priority of 5 is to be used.
- 1-10
- Specify the duplicate route priority value to be used. This value determines which route is selected when multiple routes with the same value for route destination, subnet mask, and type of service satisfy the primary route selection criteria. Routes with a higher duplicate route priority (DUPRTEPTY) are used before routes with a lower one.
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)
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.
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.
*ESCAPE Messages
- TCP1D03
- &1 member record length not correct.
- TCP1D04
- Error occurred processing member &1 of &2/&3.
- TCP1901
- Internet address &1 not valid.
- TCP1902
- Internet address &1 not valid.
- TCP1908
- Internet address &1 not valid.
- TCP261C
- Process completed successfully.
- TCP2665
- &2 &1 not added successfully.
- TCP2666
- &2 &1 not added.
- TCP8050
- *IOSYSCFG authority required to use &1.
- TCP9509
- Line &1 not found.
- TCP9999
- Internal system error in program &1.