CL Command Reference - CHGTCPA
CL Command List > CHGTCPA Reference
Description:
The Change TCP/IP Attributes (CHGTCPA) command is used to change the TCP, UDP, IP, and ARP protocol layer attributes. The changes take effect immediately.
Restriction:
. You must have input/output system configuration (*IOSYSCFG) special authority to run this command.
Examples:
Example 1: Using TCP/IP with UDP Checksum Verification
CHGTCPA UDPCKS(*YES)
This command indicates that UDP checksumming is done for UDP data.
Example 2: Using Selected IP Parameters
CHGTCPA IPDTGFWD(*YES) IPTTL(5) IPRSBTIMO(60)
This command indicates that TCP/IP has the following characteristics:
. IP datagrams are forwarded between interfaces on different subnets.
. IP time to live (TTL) is set to 5.
. IP reassembly time-out is set to 60 seconds.
Example 3: Using Selected TCP Parameters
CHGTCPA TCPKEEPALV(100) TCPURGPTR(*RFC) TCPRCVBUF(16000)
This command indicates the following:
. TCP probes the other side of a connection every 100 minutes.
. The TCP urgent pointer in the TCP header points to the last byte of the urgent data (RFC convention).
. The TCP default receive buffer size is 16000 bytes.
Example 4: Turning Off IP Source Routing
CHGTCPA IPSRCRTG(*NO)
This command indicates that IP source routing will no longer be allowed. Any IP datagrams found with IP source routing turned on will be rejected.
Example 5: Changing R1/R2 Counts and QoS Attributes
CHGTCPA TCPR1CNT(3) TCPR2CNT(10) TCPCLOTIMO(300)
IPQOSENB(*YES) IPDEADGATE(*YES)
This command indicates the following:
. TCP is set to request a different network route after 3 unacknowledged transmissions.
. TCP is set to stop retransmitting an unacknowledged packet after 10 unsuccessful attempts.
. TCP is set to wait 300 seconds (5 minutes) before reusing a closed connection socket pair.
. Quality of Service (QoS) is enabled. v Dead gateway detection is enabled.