Verify TCP/IP Connection (VFYTCPCNN)
| Where allowed to run: All environments (*ALL) Threadsafe: No |
Parameters Examples Error messages |
The Verify TCP/IP Connection (VFYTCPCNN) command, also known as PING, tests the connectivity between a system and the remote system specified by the remote system parameter.
Notes:
- The VFYTCPCNN (PING) command cannot be used to verify IP over SNA connections.
- The local domain name is used by many applications including PING. PING appends the local domain to a host name if a domain is not specified or if a period (.) does not appear at the end of the specified host name.
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Parameters
| Keyword | Description | Choices | Notes |
|---|---|---|---|
| RMTSYS | Remote system | Character value, *INTNETADR | Required, Positional 1 |
| INTNETADR | Remote internet address | Character value | Optional |
| ADRVERFMT | Address version format | *CALC, *IP4, *IP6 | Optional |
| MSGMODE | Message mode | Element list | Optional |
| Element 1: Response message detail | *VERBOSE, *QUIET | ||
| Element 2: Summary, if response errors | *COMP, *ESCAPE | ||
| PKTLEN | Packet length (in bytes) | 8-65500, 256 | Optional |
| NBRPKT | Number of packets | 1-999, 5 | Optional |
| WAITTIME | Wait time (in seconds) | 1-120, 1 | Optional |
| LCLINTNETA | Local internet address | Character value, *ANY | Optional |
| TOS | Type of service | *MINDELAY, *MAXTHRPUT, *MAXRLB, *MINCOST, *NORMAL | Optional |
| IPTTL | IP time to live (hop limit) | 1-255, *DFT | Optional |
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Remote system (RMTSYS)
Specifies the remote system name of the host with which the Verify TCP/IP operation takes place. To be successful, the name must be valid, and the remote system must be able to communicate with the local system. You can assign names to an internet address by using either of the following:
- Work with Host Table menu, which is an option on the Configure TCP/IP menu.
- Remote name server to map a remote system name to an internet address.
Host name resolution will depend on the value specified for the Address version format (ADRVERFMT) parameter.
- *INTNETADR
- The remote system is identified by the value specified for the Remote internet address (INTNETADR) parameter.
- character-value
- Specify the remote system name to be verified.
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Remote internet address (INTNETADR)
Specifies the remote internet address. Either a valid IP Version 4 or IP Version 6 address will be accepted. An IP Version 4 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.
- character-value
- Specify the internet address of the remote system. If the internet address is entered from a command line, the address must be enclosed in apostrophes.
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Address version format (ADRVERFMT)
Specifies how the host name specified for the Remote system (RMTSYS) parameter is to be resolved.
- *CALC
- The host name resolution method will be 'calculated' (determined) based on the host name entered in the RMTSYS parameter. IP Version 6 host name resolution will be performed if the system has at least one IP Version 6 address configured. If an IP Version 6 address is not found, IP Version 4 host name resolution will be performed if the system has at least one IP Version 4 address configured. The loopback address is not considered in this case as a configured address.
- *IP4
- Use the IP Version 4 host name resolution method.
- *IP6
- Use the IP Version 6 host name resolution method.
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Message mode (MSGMODE)
Specifies the amount of information to be displayed.
Element 1: Response message detail
- *VERBOSE
- Display messages as each PING response arrives.
- *QUIET
- Display only the initial PING (VFYTCPCNN) message and the summary messages.
Element 2: Summary, if response errors
- *COMP
- If the PING (CFYTCPCNN) request is successful, the summary message returned is a completion message.
- *ESCAPE
- A monitorable escape message is returned. This is useful if you have written a program to issue the PING request and wish to monitor the PING request for errors. See the error messages section of the PING (VFYTCPCNN) command help for a list of possible escape messages.
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Packet length (in bytes) (PKTLEN)
Specifies the length (in bytes) of the data in the packets that are sent to the remote system. This does not include packet headers.
- 256
- The packet data length is 256 bytes.
- 8-65500
- Specify the number of bytes of data in each packet.
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Number of packets (NBRPKT)
Specifies the number of packets that are sent to the remote system.
- 5
- Five packets are sent.
- 1-999
- Specify the number of packets that are sent to the remote system.
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Wait time (in seconds) (WAITTIME)
Specifies the number of seconds to wait for the return (echo) packet before declaring this packet transfer a failure.
- 1
- The system waits 1 second.
- 1-120
- Specify the number of second to wait.
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Local internet address (LCLINTNETA)
Specifies the local internet address of the interface that the outbound packets are to use. Any valid IP Version 4 or IP Version 6 address will be accepted. An IP Version 4 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.
- *ANY
- Use any interface's local internet address.
- character-value
- Specify the local internet address.
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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.
Note: This parameter is not used if IP Version 6 address resolution is used for verifying connectivity to a remote system.
- *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.
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IP time to live (hop limit) (IPTTL)
Specifies the IP datagram (packet) time-to-live value. The datagram is valid only for the number of router hops specified by this parameter. The time-to-live value acts as a "hop counter". The counter is decremented each time the datagram passes through a router or gateway. Limiting the validity of the datagram by the number of hops helps to prevent internet routing loops.
Note: IP Version 6 refers to this parameter as the hop limit.
- *DFT
- Use the default time-to-live value.
The default time-to-live value for multicast addresses is 1. The default time-to-live value for all other addresses is specified by the IPTTL parameter of the Change TCP/IP Attributes (CHGTCPA) command.
- 1-255
- Specify an IP datagram (packet) time-to-live value.
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Examples
Example 1: Verify TCP/IP Connection with a Specified Host Name
VFYTCPCNN RMTSYS(IPHOST) PKTLEN(100) NBRPKT(10)
WAITTIME(15)
This command attempts to send 10 packets of 100 bytes each to a remote system (known to the TCP/IP configuration as IPHOST) over a TCP/IP link. Each packet transfer must take place within 15 seconds or it fails.
Example 2: Verify TCP/IP Connection with an IP Address
VFYTCPCNN RMTSYS(*INTNETADR) INTNETADR('128.1.1.10')
PKTLEN(100) NBRPKT(10) WAITTIME(15)
This command attempts to send 10 packets of 100 bytes each to a remote system over a TCP/IP interface. The user represents the RMTSYS with its internet address 128.1.1.10, rather than with an assigned system name. Each packet transfer that takes more that 15 seconds fails.
Example 3: Verify TCP/IP Connection with Host Name and Using a Specific Local Interface Address
VFYTCPCNN RMTSYS(IPHOST) MSGMODE(*QUIET)
LCLINTNETA('9.2.2.3')
This command attempts to send 5 packets (default) of 256 bytes each (default) to a remote system over a specific TCP/IP interface that has the local address 9.2.2.3.
Because MSGMODE(*QUIET) is specified, only the primary output messages are displayed. The interface parameter is useful on multi-homed hosts to verify network connectivity through a specific physical interface.
Example 4: Verify TCP/IP Connection with an IP Version 6 Address
VFYTCPCNN RMTSYS(*INTNETADR)
INTNETADR('1:2:3:4:5:6:7:8')
This command attempts to verify the TCP/IP connection of a remote system that has the local address of 1:2:3:4:5:6:7:8.
Example 5: Verify TCP/IP Connection with a Specified IP Version 6 Defined Host Name
VFYTCPCNN RMTSYS(IPV6HOST)
This command attempts to send 5 packets (default) of 256 bytes each (default) to a remote system (known to the IP Version 6 TCP/IP configuration as IPV6HOST) over a TCP/IP link.
The default "Address version format" is *CALC. Host name resolution may return multiple IP addresses for a given host name. But, in the case (*CALC), the first IP address (IP Version 4 or IP Version 6) resolved will be the address used when attempting to verify its connection over a TCP/IP link.
Example 6: Verify TCP/IP Connection and Explicitly Use IP Version 6 Host Name Resolution
VFYTCPCNN RMTSYS(IPV6HOST) ADRVERFMT(*IP6)
This command attempts to send 5 packets (default) of 256 bytes each (default) to a remote system (known to the IP Version 6 TCP/IP configuration as IPV6HOST) over a TCP/IP link.
This example differs from example 5 in that only a valid IP version 6 resolved address, for IPV6HOST, will be used when attempting to verify its connection over a TCP/IP link.
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Error messages
*ESCAPE Messages
- TCP3210
- Connection verification statistics: &1 of &2 successful (&3 %).
- TCP3219
- Address &1 does not match address version format &2.
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