| Where allowed to run: All environments (*ALL) Threadsafe: No |
Parameters Examples Error messages |
The Change TCP/IP Route (CHGTCPRTE) command is used to change an existing route in the Transmission Control Protocol/Internet Protocol (TCP/IP) configuration.
Five parameter values uniquely define an IPv4 route. These values are the route destination (RTEDEST), the subnet mask (SUBNETMASK), the type of service (TOS), the IPv4 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.
Four parameter values uniquely define an IPv6 route. These values are the route destination (RTEDEST), the address prefix length (ADRPFXLEN), the IPv6 address of the next system on the route (NEXTHOP), and the binding line description (BINDLIND).
Restrictions:
| Top |
| Keyword | Description | Choices | Notes |
|---|---|---|---|
| RTEDEST | Route destination | Character value, *DFTROUTE, *DFTMCAST, *DFT6ROUTE, *DFT6MCAST | Required, Key, Positional 1 |
| SUBNETMASK | Subnet mask | Character value, *NONE, *HOST | Optional, Key, Positional 2 |
| TOS | Type of service | *MINDELAY, *MAXTHRPUT, *MAXRLB, *MINCOST, *NORMAL | Optional, Key, Positional 3 |
| NEXTHOP | Next hop | Character value | Optional, Key |
| ADRPFXLEN | Address prefix length | 1-128, 64, *HOST, *NONE | Optional, Key |
| BINDIFC | Preferred binding interface | Character value, *NONE | Optional, Key |
| BINDLIND | Binding line description | Name | Optional, Key |
| MTU | Maximum transmission unit | 576-16388, *SAME, *IFC | Optional |
| METRIC | Route metric | 1-16, *SAME | Optional |
| REDST | Route redistribution | *SAME, *YES, *NO | Optional |
| DUPRTEPTY | Duplicate route priority | 1-10, *SAME, *HIGH, *MEDIUM, *LOW | Optional |
| TEXT | Text 'description' | Character value, *SAME, *BLANK | Optional |
| Top |
Specifies the route destination being changed.
For an IPv4 route, 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.
For an IPv6 route, the entire 16 byte IPv6 address must be specified, and the suffix portion of the RTEDEST field must be zero. For example, a RTEDEST with value 1234:5678:: and address prefix length (ADRPFXLEN) of 32 is a valid combination, but a RTEDEST with value 1234:5678:8000:: and ADRPFXLEN of 32 is not.
This is a required parameter.
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).
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:
For an IPv6 route, the route destination is specified in the form x:x:x:x:x:x:x:x, where x is a hexadecimal number ranging from 0 through X'FFFF'. "::" may be used once in the route destination to indicate one or more groups of 16 bits of zeros. The "::" may be used to compress leading, imbedded, or trailing zeros in the route destination. The suffix portion of the route destination must contain zeros.
| Top |
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.
SUBNETMASK is ignored if RTEDEST contains an IPv6 address.
| Top |
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.
TOS is ignored if RTEDEST contains an IPv6 address.
| Top |
Specifies the internet address of the next system (gateway) on the route.
Note: If RTEDEST specifies an IPv4 address, NEXTHOP must contain an IPv4 address. If RTEDEST specifies an IPv6 address, NEXTHOP must contain an IPv6 address.
An IPv4 internet address is specified in the form nnn.nnn.nnn.nnn, where nnn is a decimal number ranging from 0 through 255. An IPv4 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.
An IPv6 internet address is specified in the form x:x:x:x:x:x:x:x, where x is a hexadecimal number ranging from 0 through X'FFFF'. "::" may be used once in the IPv6 address to indicate one or more groups of 16 bits of zeros. The "::" may be used to compress leading, imbedded, or trailing zeros in the address.
:: (null IPv6 address), ::1 (IPv6 loopback address) and addresses beginning with FF (IPv6 multicast address) are not allowed.
If the internet address is entered from a command line, the address must be enclosed in apostrophes.
| Top |
Specifies the IPv6 address prefix length (in bits) of the RTEDEST parameter. The address prefix length specifies how much of the leftmost portion of an IPv6 address is the subnet prefix. This parameter applies only if RTEDEST is an IPv6 address.
| Top |
Specifies the IP interface this route is bound to.
BINDIFC is ignored if RTEDEST contains an IPv6 address.
| Top |
Specifies the line description (LIND) object to which this route is bound. This value must be specified for an IPv6 route and is ignored for an IPv4 route.
| Top |
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. For IPv4, the minimum size of any maximum transmission unit value is 576 bytes. For IPv6, the minimum value is 1280 bytes.
Notes:
| Top |
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.
METRIC is ignored if RTEDEST contains an IPv6 address.
| Top |
Specifies whether this static route information will be shared with other routers. You can reduce traffic on this route by specifying *NO.
REDST is ignored if RTEDEST contains an IPv6 address.
Note: REDST(*YES) is analogous to the RIPv1 specification of STATIC. REDST(*NO) is analogous to the RIPv1 specification of PASSIVE.
| Top |
Specifies the duplicate route priority of this static route. This value determines which route is selected when multiple routes with the same value for route destination, subnet mask, and type of service (for IPv4 routes) or route destination and address prefix length (for IPv6 routes) satisfy the primary route selection criteria. Routes with a higher duplicate route priority (DUPRTEPTY) are used before routes with a lower one. The values allowed for this parameter are 1 (lowest priority) to 10 (highest priority).
Note: IPv4 routes have 10 different priority values. IPv6 routes have only 3: *HIGH, *MEDIUM, and *LOW. For an IPv6 route, if 1, 2, or 3 are specified for DUPRTEPTY, the route will have *LOW priority. If 4, 5, or 6 are specified for DUPRTEPTY, the IPv6 route will have *MEDIUM priority. If values 7, 8, 9, or 10 are specified for DUPRTEPTY, the IPv6 route will have *HIGH priority.
| Top |
Specifies text that briefly describes the route.
| Top |
Example 1: Changing a Route
CHGTCPRTE RTEDEST('132.65.0.0') SUBNETMASK('255.255.0.0')
TOS(*MINDELAY) NEXTHOP('132.65.34.98') MTU(1024)
This command changes the route identified by route destination 132.65.0.0 with a subnetmask of 255.255.0.0 and type of service of *MINDELAY. The change is to use a maximum transmission unit (MTU) of 1024.
Example 2: Changing an IPv4 Default Route
CHGTCPRTE RTEDEST(*DFTROUTE) SUBNETMASK(*NONE) TOS(*NORMAL)
NEXTHOP('186.49.126.108') MTU(1024)
This command changes the default route identified by next-hop value 186.49.126.108 to use an MTU value of 1024.
Example 3: Changing an IPv6 Route
CHGTCPRTE RTEDEST('1234:5678::') ADRPFXLEN(32) BINDLIND(ETHLINE)
NEXTHOP('AAAA::BBBB') DUPRTEPTY(*HIGH)
TEXT('High priority route')
This command changes the route identified by route destination 1234:5678::, address prefix length 32, binding line description ETHLINE, and next hop AAAA::BBBB. The duplicate route priority is changed to *HIGH and the text description is changed to "High priority route".
Example 4: Changing an IPv6 Default Route
CHGTCPRTE RTEDEST(*DFT6ROUTE) ADRPFXLEN(*NONE) BINDLIND(ETHLINE2)
NEXTHOP('AAAA::CCCC') MTU(1280)
This command changes the route identified by route destination *DFT6ROUTE, address prefix length *NONE, binding line description ETHLINE2, and next hop AAAA::CCCC. The MTU value is changed to 1280.
| Top |
*ESCAPE Messages
| Top |