IBM 4400-006 User Manual - Page 240

Chapter 11 Handling MVS Connectivity Problems Port Switching Printer Sharing To support printer sharing, IBM 10/100Base-T Ethernet Interface printers automatically switch among all attached ports (serial port, the twinax or coax port, or the Ethernet network port). Basically, the printer prints jobs for one port until no new jobs appear and the port "times out". The printer then switches to the next port and does the same thing. To change the default "time out" value for a port, update the TIMEOUT value for the port on the appropriate menu (Serial Interface, Ethernet, Twinax Interface, or Coax Interface). Handling MVS Connectivity Problems SMART If you encounter problems when "ping"-ing a network printer from MVS, here is how to resolve them. Ping is Not Successful If the "ping" is not successful, verify the following: • The printer is powered on. • The IP address is unique in the TCP/IP network. If the IP address of the MVS system is not unique, see your network administrator to resolve the IP address problem. • The Maximum Transmission Unit (MTU) size of the IP packet for the MVS system is equal to the MTU size of the printer. For information about the values recommended for the MVS system, see "Modify the TCP/IP Profile in MVS" on page 228. To change the MTU size for the MVS system, change the GATEWAY statement in the MVS TCP/IP profile, and restart TCP/IP to pick up the changes. You cannot change the MTU size on an IBM 10/100Base-T Ethernet Interface printer. The MTU size is fixed at 1024 bytes. If these items are all in order, consult your TCP/IP network administrator about a possible network problem. 240