iSeries TCP/IP Configuration and Reference Version 5 SC41-5420-04
iSeries TCP/IP Configuration and Reference Version 5 SC41-5420-04
Note Before using this information and the product it supports, be sure to read the information in “Notices” on page 93. Fifth Edition (May 2001) This edition replaces SC41-5420-03. This edition applies only to reduced instruction set computer (RISC) systems. © Copyright International Business Machines Corporation 1997, 2001. All rights reserved. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
Contents About TCP/IP Configuration and Reference (SC41-5420) . . . . . . . . v Prerequisite and related information . . vii Operations Navigator . . . . . . . . . . . vii How to send your comments . . . . . ix Summary of changes . . . . . . . . . xi Chapter 1. Configuring TCP/IP . . . . . 1 What you need to know before you can configure TCP/IP . . . . . . . . . . . . . . . . 1 Planning for TCP/IP Installation and Configuration . 2 Gathering Information About your Network . . .
IP Multicasting . . . . . . . . . . . . . 68 Multicast Application Programming Information 68 Multicast Restrictions . . . . . . . . . . 68 Chapter 3. TCP/IP Performance . . . . 71 | *BASE Pool Size . . . . . . . . . . . . . TCP/IP Jobs . . . . . . . . . . . . . . TCP/IP Protocol Support Provided by IOP . . . . Merge Host Table Performance . . . . . . . . Running TCP/IP Only: Performance Considerations 71 71 71 73 73 Appendix A. Configuring a Physical Line for TCP/IP Communication . . . .
About TCP/IP Configuration and Reference (SC41-5420) This book contains information about configuring Transmission Control Protocol/Internet Protocol (TCP/IP) and operating and managing your network. Most topics have been moved to the Information Center. Note: This book contains links to various topics within the Information Center and to references outside the Information Center. The URL addresses for these links are current for V5R1. © Copyright IBM Corp.
vi OS/400 TCP/IP Configuration and Reference V5R1
Prerequisite and related information Use the iSeries Information Center as your starting point for looking up iSeries and AS/400e technical information. You can access the Information Center two ways: v From the following Web site: http://www.ibm.com/eserver/iseries/infocenter v From CD-ROMs that ship with your Operating System/400 order: iSeries Information Center, SK3T-4091-00.
viii OS/400 TCP/IP Configuration and Reference V5R1
How to send your comments Your feedback is important in helping to provide the most accurate and high-quality information. If you have any comments about this book or any other iSeries documentation, fill out the readers’ comment form at the back of this book. v If you prefer to send comments by mail, use the readers’ comment form with the address that is printed on the back.
x OS/400 TCP/IP Configuration and Reference V5R1
Summary of changes This is the fifth edition of TCP/IP Configuration and Reference. Most topics from the fourth edition of TCP/IP Configuration and Reference have been moved to the iSeries Information Center.
xii OS/400 TCP/IP Configuration and Reference V5R1
Chapter 1. Configuring TCP/IP This chapter explains how to configure an iSeries 400® server for Transmission Control Protocol/Internet Protocol (TCP/IP). If this is the first time that you have configured TCP/IP on an iSeries, you should read the entire chapter before performing any of the configuration tasks. If you are unfamiliar with TCP/IP, see TCP/IP (http://publib.boulder.ibm.com/pubs/html/as400/v5r1/ic2924/info/ rzahgictcp2.
v Working with TCP/IP host tables, including configuring a TCP/IP host name and domain name v Verifying a TCP/IP connection (PING) Planning for TCP/IP Installation and Configuration If you are in charge of configuring an iSeries server for TCP/IP communications you will, in most cases, include your server in an existing TCP/IP network. Before you are able to start configuring, you will need to collect all of the required information.
“Step 6—Configuring TCP/IP Host Table Entries” on page 18. For information about configuring and using a DNS server, see DNS(http://publib.boulder.ibm.com/pubs/html/as400/v5r1/ic2924/info/rzakk/ rzakkkickoff.htm) in the Information Center. If you are using the Supplemental Manuals CD, then switch to the iSeries Information Center CD to access this information. 5. Obtain X.25 network addresses: If you plan to use TCP/IP on an X.
Table 1.
Table 2. Local TCP/IP Host Information (continued) X.25 / Remote System Information Host #1 Host #2 Host #3 Internet address X.25 network address PVC channel ID Packet or window size Once you have documented configuration information, you are ready to install the TCP/IP program on your server. The information in the section that follows will help you do that. See “Installing the TCP/IP Application Programs”.
v Automatic IPL The Automatic IPL option determines whether the system automatically starts when the installation process has completed successfully. When TCP/IP successfully installs, either the Work with Licensed Programs menu or the Sign On display appears. 6. Select option 50 (Display log for messages) to verify that you have installed the licensed program successfully.
v Option 5. Start TCP/IP servers: Select this option to issue the Start TCP/IP Server (STRTCPSVR) command. This command is used to start the TCP/IP application servers that are shipped with OS/400® or the TCP/IP licensed program (5769-TC1). This command starts the TCP/IP application server jobs in the QSYSWRK subsystem. v Option 6. End TCP/IP servers: Select this option to issue the End TCP/IP Server (ENDTCPSVR) command.
CFGTCP Configure TCP/IP Select one of the following: 1. 2. 3. 4. 5. System: SYSNAM890 Work with TCP/IP interfaces Work with TCP/IP routes Change TCP/IP attributes Work with TCP/IP port restrictions Work with TCP/IP remote system information 10. Work with TCP/IP host table entries 11. Merge TCP/IP host table 12. Change TCP/IP domain information 20. Configure TCP/IP applications 21. Configure related tables 22.
server) was removed from the menu. Option 12, formerly Change local domain and host names, was renamed to Change TCP/IP domain information. v Option 20. Configure TCP/IP applications: Select this option to configure the TCP/IP applications that are installed on your system. The list of applications varies depending on whether the TCP/IP licensed program is installed on your system.
3. 4. 5. 6. 7. Configuring Configuring Configuring Configuring Configuring TCP/IP routes TCP/IP attributes remote system information (X.25) host table entries local domain and host name 8. Starting TCP/IP 9. Verifying TCP/IP connection 10. Saving the TCP/IP configuration Important Note: To perform the configuration steps discussed throughout this chapter, you need the special authority of *IOSYSCFG defined in your user profile.
Subnet mask Defines which part of an Internet address forms the subnet (subnetwork) field of an Internet address. An example of a single-network subnet mask is: 255.255.255.128. Line description Contains information describing a communications line that is attached to the iSeries server, as defined previously in “Step 1—Configuring a Line Description” on page 10. To find the names of the currently defined line descriptions, use the Work with Line Descriptions (WRKLIND) command.
Add TCP/IP Interface (ADDTCPIFC) Type choices, press Enter. Internet address . . . . . . . . Line description . . . . . . . . Subnet mask . . . . . . . . . . Associated local interface . . . Type of service . . . . . . . . Maximum transmission unit . . . Autostart . . . . . . . . . . . PVC logical channel identifier + for more values X.25 idle circuit timeout . . . X.25 maximum virtual circuits . X.25 DDN interface . . . . . . . TRLAN bit sequencing . . . . . .
same network that the server is attached to. You must also add routing entries to allow TCP/IP clients that are attempting to reach your server from a remote network to function correctly. For example, suppose that someone using a PC is using the TELNET application to start a remote terminal session on your server. The application on the PC must know the route or path to reach the server. Your server must also be able to determine the route back to the PC.
Preferred binding interface The preferred binding interface allows administrators to choose which of the TCP/IP interfaces that they prefer the route to be bound to or on. This provides the administrator with more flexibility to route traffic over a specific interface. The interface is preferred because the route is bound to the indicated interface if the interface is active.
Add TCP/IP Route (ADDTCPRTE) Type choices, press Enter. Route destination . . . . . Subnet mask . . . . . . . . Type of service . . . . . . Next hop . . . . . . . . . . Preferred binding interface Maximum transmission unit . Route metric . . . . . . . . Route redistribution . . . . Duplicate route priority . . F3=Exit F4=Prompt F24=More keys . . . . . . . . . . > '9.4.6.128' . > '255.255.255.128' . *NORMAL *MINDELAY, *MAXTHRPUT... . > '9.4.73.193' . *NONE . 576 576-16388, *IFC . 1 1-16 . *NO *NO, *YES .
Step 4—Configuring TCP/IP attributes To configure the TCP/IP attributes, type option 3 on the Configure TCP/IP menu. The Change TCP/IP Attributes (CHGTCPA) display is shown (Figure 8). Change TCP/IP Attributes (CHGTCPA) Type choices, press Enter. TCP keep alive . . . . . TCP urgent pointer . . . TCP receive buffer size TCP send buffer size . . UDP checksum . . . . . . IP datagram forwarding . IP source routing . . . IP reassembly time-out . IP time to live . . . . ARP cache timeout . . .
Work with TCP/IP Remote System Information Type options, press Enter. 1=Add 4=Remove 5=Display Opt _ Internet Address _______________ Network Address PVC System: SYSNAM890 Reverse Charges (No remote system information) Figure 9. Work with Remote System (X.25) Information Type option 1 (Add) at the input-capable top list entry to go to the Add TCP/IP Remote System (ADDTCPRSI) display, as shown in Figure 10. Add TCP/IP Remote System (ADDTCPRSI) Type choices, press Enter. Internet address . . . . . . .
information. If DDN is specified as *YES on the X.25 connection, you should not specify remote system information for that interface or its associated DDN network systems. 2. A routing error occurs when both of the following are true: v The remote system information associated with the Internet address is an extended data terminal equipment (DTE) address. v The configured X.25 interface’s line does not support X.25 extended addressing.
To add an entry to your local host table, type option 10 on the Configure TCP/IP menu. The Work with TCP/IP Host Table Entries display is shown in Figure 11. Work with TCP/IP Host Table Entries Type options, press Enter. 1=Add 2=Change 4=Remove Opt _ _ Internet Address _______________ 127.0.0.1 5=Display System: SYSNAM890 7=Rename Host Name LOOPBACK LOCALHOST Figure 11.
Work with TCP/IP Host Table Entries Type options, press Enter. 1=Add 2=Change 4=Remove Internet Opt Address _ _______________ _ 9.4.73.211 _ 9.4.73.212 _ 9.4.73.214 _ 9.4.191.76 _ 127.0.0.1 5=Display System: SYSNAM890 7=Rename Host Name BERN SYSNAM890 MACIAN DNS LOOPBACK LOCALHOST Figure 13. Work with Host Table Entries, Display 2 of 2 The iSeries TCP/IP host table is shipped with the LOOPBACK entry. The LOOPBACK entry has an Internet address of 127.0.0.1 and two host names: LOOPBACK and LOCALHOST.
Work with TCP/IP Host Table Entries Type options, press Enter. 1=Add 2=Change 4=Remove Internet Opt Address _ _______________ _ 9.4.73.211 _ 9.4.73.212 _ 9.4.73.214 _ 9.4.191.76 _ 9.125.87.127 _ 127.0.0.1 5=Display System: SYSNAM890 7=Rename Host Name BERN SYSNAM890 MACIAN DNS SYSNAMEND.ENDICOTT.IBM.COM LOOPBACK LOCALHOST Figure 14. Example of a Fully Qualified Host Table Entry Additional host names are useful as alternative nicknames. See the examples in Figure 15. Host names need not be unique.
v Simple Mail Transfer Protocol (SMTP) requires your host name to be in the host table or on a domain name server. v You may want to use your host table on other systems in the network. Your host name must be in the host table on those systems so they can refer to your system by name. v Applications written to use host table lookup routines may require this information. When you are finished working with the host table, press F3 (Exit) or F12 (Cancel).
(http://publib.boulder.ibm.com/pubs/html/as400/v5r1/ic2924/info/rzaku/ rzakuconcat.htm) in the Information Center. If you are using the Supplemental Manuals CD, then switch to the iSeries Information Center CD to access this information. To change the local domain name, type option 12 on the Configure TCP/IP menu. The Change TCP/IP domain information display is shown in Figure 16. Change TCP/IP Domain (CHGTCPDMN) Type choices, press Enter. Host name Domain name . . . . . . . . . . . . . . . . . . . . .
Step 8—Starting TCP/IP and TCP/IP Servers Before any TCP/IP services are available on the iSeries system, TCP/IP processing must be initialized and activated. To start TCP/IP, you have two options: 1. Select option 3 from the TCP/IP Administration menu (GO TCPADM), 2. Enter the Start TCP/IP (STRTCP) command. The STRTCP command initializes and activates TCP/IP processing, starts the TCP/IP interfaces, and starts the TCP/IP server jobs. Only TCP/IP interfaces with AUTOSTART *YES are started at STRTCP time.
Using the Start TCP/IP Server (STRTCPSVR) command starts the servers individually or together. You can monitor the jobs with option 20 (Work with TCP/IP jobs in QSYSWRK subsystem) from the TCP/IP Administration menu. If you want TCP/IP processing and any related TCP/IP servers to start automatically at the initial program load (IPL), add STRTCP to the QSTRUP CL program. Note: If they are installed, the Client Access host servers are automatically started when TCP/IP is started.
Table 3. Jobs Used by TCP/IP (continued) Job Name Description ADMIN and DEFAULT ICS (HTTP) server QTWSGxxxxx Workstation gateway (there may be several) Note: 1. There may be other jobs running in the QSYSWRK subsystem that have nothing to do with TCP/IP. 2. The TCP/IP jobs in QSYSWRK run under the QTCP user profile, with two exceptions: the TFTP server runs under the QTFTP profile, and the workstation gateway server runs under the QTMTWSG profile. 3.
> ping '9.4.73.212' Verifying connection to host system 9.4.73.212. PING request 1 from 9.4.73.212 took 24 ms. 256 bytes. PING request 2 from 9.4.73.212 took 11 ms. 256 bytes. PING request 3 from 9.4.73.212 took 31 ms. 256 bytes. PING request 4 from 9.4.73.212 took 11 ms. 256 bytes. PING request 5 from 9.4.73.212 took 12 ms. 256 bytes. Round-trip (in milliseconds) min/avg/max = 11/17/31 Connection verification statistics: 5 of 5 successful TTL TTL TTL TTL TTL 64. 64. 64. 64 64. (100 %). Figure 18.
additional systems to your network, you also need to verify their TCP/IP connection. The examples in the following paragraphs show you how to verify a remote TCP/IP connection. Use the system menus or the Verify TCP/IP Connection (VFYTCPCNN or PING) command to verify your system’s ability to communicate with a remote system using TCP/IP. Note: PING uses the Internet Control Message Protocol (ICMP) to send data to a host’s Internet address and waits for a response.
Verify TCP/IP Connection (PING) Type choices, press Enter. Remote system . . . . . . . . . sysnam36.sysnam123.ibm.com__________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ Remote internet address . . . . _____________________________ Additional Parameters Message mode: Response message detail . .
Verify TCP/IP Connection (PING) Type choices, press Enter. Remote system . . . . . . . . . > SYSNAM36.SYSNAM123.IBM.COM_____________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ Additional Parameters Message mode: Response message detail . . Summary, if response errors Packet length (in bytes) . . .
Note: You do not have to end TCP/IP in order to save the configuration files. However, you should end TCP/IP before any TCP/IP configuration files are restored. Chapter 1.
32 OS/400 TCP/IP Configuration and Reference V5R1
Chapter 2. TCP/IP: Operation, Management, and Advanced Topics This chapter discusses managing your network by using the NETSTAT command, and the maintenance of host tables. In addition, this chapter covers other topics beyond those that are required to configure and use TCP/IP on iSeries 400. This information may help you to understand and maximize your usage of the iSeries TCP/IP support. TCP/IP on an iSeries server can also be managed by Simple Network Management Protocol (SNMP).
Work with TCP/IP Network Status Select one of the following: System: SYSNAM04 1. Work with TCP/IP interface status 2. Display TCP/IP route information 3. Work with TCP/IP connection status Figure 24. Work with TCP/IP Network Status Work with TCP/IP Interface Status The Work with TCP/IP Interface Status display, as shown in Figure 25, provides the most current summary of interface activity.
Work with TCP/IP Interface Status Type options, press Enter. 5=Display details 8=Display associated routes 12=Work with configuration status Internet Opt Address 9.125.87.10 9.125.87.222 127.0.0.1 Subnet Mask 255.255.255.0 255.255.255.0 255.0.0.0 Type of Service *MAXTHRPUT *NORMAL *NORMAL 9=Start MTU 1989 1989 576 System: SYSNAM04 10=End Line Type *TRLAN *TRLAN *NONE Figure 26.
depends mainly on machine use and the size of the processor. To determine whether the interface has started, view the messages in the QTCPIP job log and the QSYSOPR message queue. Ending TCP/IP Interfaces The ENDTCPIFC (End TCP/IP Interface) command ends an existing TCP/IP interface immediately. As a result, all TCP/IP connections using this interface also end immediately.
v The network ID of the interface must be equal to the logical AND of the next hop for the route and the subnet mask for the interface. Notes: 1. If the next hop of a route is identical to an interface’s IP address, that route will never be bound to another interface. 2. When starting interfaces (if all interfaces are currently inactive) routes are bound to the interfaces with the same best-match-first algorithm. An exception is if the route is defined with a preferred binding interface.
Display TCP/IP Route Information Type options, press Enter. 5=Display details Route Opt Destination 9.125.87.0 9.125.87.0 9.125.109.3 127.0.0.
contain an asterisk (*). When an application requests a connection to a listening socket, a new connection is created. The remote Internet address and remote port are shown for the new connection. The listening socket always remains in the list of connections. Work with TCP/IP Connection Status Local internet address . . . . . . . . . . . : *ALL System: SYSNAM04 Type options, press Enter. 4=End 5=Display details Remote Opt Address * * * * * * * * * * 9.5.1.
Work with TCP/IP Connection Status Local internet address . . . . . . . . . . . : *ALL System: SYSNAM04 Type options, press Enter. 4=End 5=Display details Remote Opt Address * * * * * 9.5.1.131 9.5.1.180 9.5.15.134 9.130.38.18 9.130.38.74 9.130.38.74 Remote Port * * * * * 1954 1211 1024 2099 1125 1126 Local Address * * * * 9.125.87.222 9.125.87.10 9.125.87.10 9.125.87.10 9.125.87.222 9.125.87.10 9.125.87.
Confirm End of TCP/IP Connections Local internet address . . . . . . . . . . . : *ALL System: SYSNAM04 Press Enter to confirm your choices for 4=End. Press F12 to return to change your choices. Remote Opt Address 4 9.5.15.134 Remote Port 1024 F11=Display connection state F22=Display entire field Local Address 9.125.87.10 F12=Cancel Local Port telnet Type *TCP F14=Display port numbers Bottom Figure 32.
Work with Configuration Status Position to . . . . . Starting characters Type options, press Enter. 1=Vary on 2=Vary off 5=Work with job 9=Display mode status ... Opt Description TRNLINE TRNLINET TRNLITCP SYSNAM04 04/26/94 15:55:58 Status ACTIVE ACTIVE ACTIVE 8=Work with description -------------Job-------------QTCPIP QTCP 007936 Figure 33.
Display Multicast Host Groups Interface internet address Host Group 224.0.0.1 225.4.5.6 233.32.40.51 224.0.0.9 229:200:100:1 F3=Exit F5=Refresh F12=Cancel System: 10.5.5.55 . . . . . . . . . . . : Hardware Address 01:00:5E:00:00:01 01:00:5E:04:05:06 01:00:5E:20:28:33 01:00:5E:00:00:09 01:00:5E:48:64:01 F6=Print Host Group F9=Command line SYSNAM04 Hardware Address Bottom F11=Hide hardware address Figure 34.
Display TCP/IP Interface Status Interface host name . . . . . Internet address . . . . . . Subnet mask . . . . . . . . Network address . . . . . . Host address . . . . . . . Directed broadcast address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : : : : : : System: SYSNAM04 sysnam04.endicott.ibm. > 9.125.87.10 255.255.255.0 9.125.87.0 0.0.0.10 9.125.87.255 Interface status . . . . Change date/time . . . . Line description . . . . Line type . . .
Display Associated Routes Interface internet address . . . . . . . . . : System: 9.125.87.10 SYSNAM04 Type options, press Enter. 5=Display details Route Opt Destination 9.125.87.0 *DFTROUTE F3=Exit F5=Refresh F13=Sort by column Subnet Mask 255.255.255.0 *NONE F6=Print list F17=Top Next Hop *DIRECT 9.125.87.169 Route Available *YES *YES F11=Display route type F18=Bottom Bottom F12=Cancel Figure 36.
Display TCP/IP Route Details Route information: Route destination . . . . . . . Subnet mask . . . . . . . . . . Next hop host name . . . . . . Next hop . . . . . . . . . . . Type of service . . . . . . . . Route available . . . . . . . . Route type . . . . . . . . . . Route source . . . . . . . . . Change date/time . . . . . . . Route maximum transmission unit Reference count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Display TCP/IP Route Information System: Type options, press Enter. 5=Display details Route Opt Destination 9.125.87.0 9.125.87.0 9.125.109.3 127.0.0.0 *DFTROUTE *DFTROUTE F3=Exit F5=Refresh F13=Sort by column Subnet Mask 255.255.255.0 255.255.255.0 *HOST 255.0.0.0 *NONE *NONE F6=Print list F17=Top Next Hop *DIRECT *DIRECT 9.125.87.17 *DIRECT 9.125.87.169 9.125.87.250 SYSNAM04 Route Available *YES *YES *YES *YES *YES *YES Bottom F12=Cancel F11=Display route type F18=Bottom Figure 39.
Displaying TCP/IP Connections You can request more detailed information about TCP/IP connections shown on the Work with TCP/IP Connection Status display. This information includes timing information and transmission statistics for the connection displayed. To display more information about the listed TCP/IP connections: 1. Type 5 in the option field for each connection about which you want more information. 2. Press the Enter key. A series of up to three displays for each connection appears.
Display TCP Connection Status Bytes out . . . . . . . . Outgoing bytes buffered User send next . . . . Send next . . . . . . . Send unacknowledged . . Outgoing push number . Outgoing urgency number Outgoing window number Bytes in . . . . . . . . Incoming bytes buffered Receive next . . . . . User receive next . . . Incoming push number . Incoming urgency number Incoming window number Press Enter to continue. F3=Exit F5=Refresh F14=Display port numbers . . . . . . . . . . . . . . . . . . . . . . . . . . .
(SNMP). For additional information about SNMP, see resources in the Information Center: Supplemental Manuals. Display TCP/IP Connection Totals TCP connection information: Currently established . . . Active opens . . . . . . . Passive opens . . . . . . . Attempted opens that failed Established and then reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : : : : : System: 1 0 0 0 0 TCP send information: Segments sent . . . . . . . . . . . . . . .
Managing TCP/IP Host Tables In a large network, it can be more efficient to administer iSeries TCP/IP from a central site. Working with the host table would be time consuming if each system is individually updated with the TCP/IP configuration menu. Updates can be made more quickly on one system and then copied to others. iSeries TCP/IP is designed to protect configuration files, including the host table.
A complete description of the *NIC format is found in Request for Comment (RFC) 952, Internet Host Table Specification. See the RFC Editor Site (http://www.rfceditor.org/rfc.html) to retrieve this RFC. The subset supported on the server is shown in Table 5. The *NIC continuation characters are not supported because the record length of the file can be up to 512 bytes. Table 5. *NIC Subset Supported on the AS400 System Delimiter Meaning 1 ; (semicolon) Indicates the beginning of a comment.
v Merge the information of the imported host table with the information that was entered by using option 10 (Work with TCP/IP host table entries) from the Configure TCP/IP menu. To merge the information, specify Replace Host Table (*No) on the Merge Host Table display. You can merge an imported host table with the local host table while TCP/IP is running by using the CFGTCP (Configure TCP/IP) command. The changes take affect the next time a TCP/IP application accesses the host table.
Step 4—Merge the File Type the following FTP subcommand: quote rcmd mrgtcpht fromfile(qusrsys/m03host) frommbr(host) IP Routing and Internet Control Message Protocol (ICMP) Redirecting Internet routing tables usually remain static for long periods. TCP/IP generates routing tables at activation time from configuration data and adjusts the routing tables based on ICMP redirects, SNMP manager requests, dead gateway processing and socket routing requests.
Figure 46. Example of ICMP Redirect To see routing changes due to ICMP redirect messages, select NETSTAT menu 2 or NETSTAT *RTE and then press PF11. Comparing the next hop in this display with the next hop present in the routing table, you can verify whether a route has been dynamically changed. Dead Gateway Processing RFC-1122, Requirements For Internet Hosts - Communication Layers, requires the IP layer to include a dead gateway algorithm to manage suspected gateway failures.
The data link layer passes a negative advice indicator to IP when it is unable to transmit data to a first-hop (directly-connected) gateway. In most cases, negative advice from the data link layer means that the Address Resolution Process (ARP) processing performed by the data link layer was unable to resolve the location of first-hop gateway on the directly connected physical network. (ARP is not performed on all physical network types. Some physical network types, such as X.
Note: The maximum number of interfaces that can be active on a line description at any given time is 128. This is true for all line types (for example, token-ring, Ethernet, frame relay, and so forth). Example: A Single Host on a Network over a Communications Line Your server uses one adapter for TCP/IP to attach to a LAN or WAN network. You add one TCP/IP interface. This TCP/IP interface includes the Internet address of your server.
addresses, your server appears as multiple TCP/IP hosts in the same TCP/IP network (Figure 49). Figure 49. Multihoming - Multiple Hosts, Single Network, Multiple Lines This scenario can be helpful for backup or to improve performance. However, there is no dynamic backup or performance balance function. Example: Multiple Hosts on Different Networks over the Same Communications Line Your server uses one adapter for TCP/IP to attach to a LAN or WAN network. You add multiple TCP/IP interfaces.
an Internet address of different TCP/IP networks. With these multiple Internet addresses, you take part in different TCP/IP networks (Figure 51). This example is a combination of all of the previous examples discussed. Figure 51. Multihoming - Multiple Hosts, Multiple Networks, Multiple Lines Example: The Multihoming function Assume servers SYSNAM02 and SYSNAM03 are connected with a public or private X.25 network. The Internet address of this network is 9.4.73.64.
Work with TCP/IP Interfaces Type options, press Enter. 1=Add 2=Change 4=Remove Internet Opt Address __ _______________ __ 9.4.73.65 __ 127.0.0.1 __ 223.1.1.17 F3=Exit F12=Cancel 5=Display Subnet Mask 9=Start F6=Print list F18=Bottom SYSNAM03 10=End Line Line Description Type 255.255.255.192 X25LINE 255.0.0.0 *LOOPBACK 255.255.255.0 X25LINE F5=Refresh F17=Top System: *X25 *NONE *X25 F11=Display interface status Figure 53.
The following table shows which type of services your server uses for some of the TCP/IP applications: Table 6.
a specific route defined. The system allows up to eight default routes, but each route must have a unique next hop value. An example of a multiple route table can be found in Figure 54. Work with TCP/IP Routes Type options, press Enter. 1=Add 2=Change 4=Remove Opt _ _ _ _ _ _ _ Route Destination ______________ *DFTROUTE *DFTROUTE *DFTROUTE 9.4.70.0 9.4.70.0 9.4.70.0 System: SYSNAM003 5=Display Subnet Mask ______________ *NONE *NONE *NONE 255.255.255.0 255.255.255.0 255.255.255.
the specified port. If no match is found, the requesting program is not allowed to use the specified port. If any port in the 1-1023 range is restricted, the following message is posted: Port restriction added but may affect TCP/IP processing If no user profiles are associated with a specific port, there are no restrictions. It is not necessary to configure port restrictions unless you are writing your own TCP/IP applications and you want to reserve the use of the applications to certain user profiles.
Add TCP/IP Port Restriction (ADDTCPPORT) Type choices, press Enter. Range of port values: Lower value . . . . Upper value . . . . Protocol . . . . . . . User profile . . . . . F3=Exit F4=Prompt F24=More keys . . . . . . . . . . . . . . . . F5=Refresh . 1060 . > *ONLY . *tcp . gerry 1-65535 1-65535, *ONLY *UDP, *TCP Character value F12=Cancel Bottom F13=How to use this display Figure 56.
Related Tables and the Host Table Socket applications require a set of tables from which they can retrieve specific TCP/IP network data when needed. These are as follows: v Host table v Service table v Protocol table v Network table The host table contains a list of host names and corresponding Internet addresses. Socket applications requesting host data obtain it either from the server host database file or from the domain name server.
The services table stores the mapping of services to ports or ports to services as shown in Figure 59. The mapping information is usually accessed with the getservbyname() and getservbyport() socket functions. Work with Service Table Entry System: Type options, press Enter.
The network table contains the networks and the Internet address associated with the network. Socket applications use the getnetbyname() and getnetbyaddr() functions to access the information in the network table (Figure 61). Work with Network Table Entry Type options, press Enter. 1=Add 4=Remove 5=Display Opt _ _ Network _____________________________________ IBM System: SYSNAM03 Internet address _______________ 9.0.0.
The TCP/IP interface now points to a specific PVC instead of a pool of SVCs. ADDTCPIFC INTNETADR('9.4.73.65') LIND(X25LINE) SUBNETMASK('255.255.255.192') PVCLGLCHLI(001) MAXSVC(0) The TCP/IP remote system information no longer includes the X.25 address to be called. Instead, the entry points to the PVC channel ID. ADDTCPRSI INTNETADR('9.4.73.66') PVCLGLCHLI(001) IP Multicasting IP multicasting is the process of transmitting an IP datagram to a host group.
supported on multi-access nonbroadcast networks. IP multicast is also not currently supported on Frame Relay, FDDI/SDDI, or ATM networks. To determine whether an interface supports multicast, enter option 14 on the Work with TCP/IP Interface Status display. If the interface supports multicast, there will be at least one Host Group entry for the All Hosts group 224.0.0.1. Otherwise, the interface does not support multicast.
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Chapter 3. TCP/IP Performance The following are performance items that should be considered when using TCP/IP. *BASE Pool Size The TCP/IP protocol and application code always runs in the *BASE pool on the iSeries 400 server. If the *BASE pool is not given enough storage, TCP/IP performance, especially SMTP performance, can be adversely affected.
v v v v Checksum calculation of outgoing TCP and UPD datagrams (prior to V4R4) Checksum verification of incoming TCP and UPD datagrams (prior to V4R4) Outbound batching of TCP and UDP datagrams. Fragmentation of TCP and UDP datagrams into segments that match the MTU size. v Starting with V4R2, iSeries collects all TCP datagrams in one batch and UDP datagrams in a second batch. Ports and IP addresses are ignored.
| | Note: If you configure your 100 Mbps ethernet line for TCPONLY, all IOP assist functions are disabled. TCP/IP-assist functions that are available on frame relay IOAs are: v #2699 Two-Line WAN IOA v #2720 PCI WAN/Twinaxial IOA v #2721 PCI Two-Line WAN IOA Communications restrictions apply if any of the following communication functions are required when using the frame relay IOAs, as listed above: v X.
If you have one of these configurations, you can use the TCPONLY parameter when you create or change your Ethernet line descriptions. Setting TCPONLY to *YES in other hardware configurations has no effect on the line.
Appendix A. Configuring a Physical Line for TCP/IP Communication On the iSeries 400, communication occurs through objects called lines, controllers, and devices. The communications objects for iSeries TCP/IP are the line descriptions, the network controller descriptions, and the network device descriptions. TCP/IP communicates over a variety of physical line types and network interfaces (NWI).
You can describe the characteristics of the communications devices using the by Create Device Description (Network) (CRTDEVNET) command or by letting the system create the device automatically when you activate TCP/IP. If you want to change controller or device descriptions, use the Change Controller Description (Network) (CHGCTLNET) and Change Device Description (Network) (CHGDEVNET) commands. For more information on changing controller or device descriptions, see Control Languages (http://publib.boulder.
If the Ethernet standard prompt is *ETHV2, the system sends and receives all TCP/IP data in Ethernet Version 2 frames. You do not need to configure any additional SSAPs for TCP/IP. Setting the Maximum Transmission Unit The maximum transmission unit (MTU) parameter that you can enter on the Add TCP/IP Interface (ADDTCPIFC) command, Add TCP/IP Route (ADDTCPRTE) command, Change TCP/IP Interface (CHGTCPIFC) command, or Change TCP/IP Route (CHGTCPRTE) command depends on the type of line that you use.
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Appendix B. TCP/IP Application Exit Points and Programs Certain TCP/IP applications provide exit points that enable them to call customer-written exit programs.
OS/400 Registration Facility Exit points for TCP/IP applications are automatically registered when the parent product or option is installed, using the OS/400 registration facility. The registration facility contains a repository that allows customers to associate their exit programs with specific exit points. TCP/IP applications check the registration facility repository to determine which exit program to call for a particular exit point.
Table 9. TCP/IP Application Exit Points (continued) TCP/IP Application Exit Point Exit Point Format Note: | | | 1 The same interface format is used for request validation for the FTP client, FTP server, REXEC server, and TFTP server. This allows the use of one exit program for request validation of any combination of these applications. 2 The same interface format is used for server log-on processing for the FTP server and REXEC server applications.
Work with Registration Information Type options, press Enter.
Work with Exit Programs Exit point: QIBM_QTMT_WSG Format: Type options, press Enter. 1=Add 4=Remove 5=Display Opt Exit Program Number Exit Program QAPP0100 10=Replace Library (No exit programs found.) Figure 65. Adding an Exit Program — Display 1 Step 2: Select the Add Exit Program option Select the add option by typing a 1 (Add) in the Opt column as shown in Figure 66. Work with Exit Programs Exit point: QIBM_QTMT_WSG Type options, press Enter.
When you add workstation gateway server exit programs, you do not need to end and restart the workstation gateway server. The WSG server checks for the exit program dynamically. When you add REXEC server exit programs, you do not need to end and restart the REXEC server. The REXEC server checks for the exit programs dynamically. Add Exit Program (ADDEXITPGM) Type choices, press Enter. Exit point . . . . Exit point format Program number . . Program . . . . . Library . . . . Text 'description' . . . . . .
Exit Point Interfaces for TCP/IP Application Exit Points | | | The exit point interfaces for TCP/IP application exit points are: v TCP/IP application request validation exit point interface v TCP/IP remote execution server command processing selection exit point interface Note: For a detailed description of the DHCP exit points and how to use them, see System API Reference (http://publib.boulder.ibm.com/pubs/html/as400/v5r1/ic2924/info/apis/ api.htm) in the Information Center.
3 TFTP server program Operation identifier INPUT; BINARY(4) Indicates the operation that the user is attempting to perform.
For operation identifiers 1 through 3, the operation-specific information contains the name of the directory or library on which the operation is to be performed. The directory or library name is formatted as an absolute path name. For operation identifiers 4 through 8, the operation-specific information contains the name of the file on which the operation is to be performed. The file name is formatted as an absolute path name.
Table 10. Application Request Validation Operation-Specific Information Operation Identifier Operation-Specific Information 0 NONE if application ID=0 0 Dotted decimal format IP address of client host when application ID=1 or 2 1-3 Absolute path name of library or directory /QSYS.LIB/QGPL.LIB1 /QOpenSys/DirA/DirAB/DirABC2 4-8 Absolute path name of file /QSYS.LIB/MYLIB.LIB/MYFILE.FILE/MYMEMB.MBR1 /QOpenSys/DirA/DirAB/DirABC/FileA12 9 CL command string : 1 QSYS.
3. If any exception is encountered when calling the exit program, the REXEC server will not allow the operation and the message ″Exception encountered for REXEC exit program &1 in library &2 for exit point &3.″ is issued to the job log. The following note applies to the TFTP server (application identifier 3): 1. For the TFTP server program, operation identifier 6 indicates the TFTP Read Request (RRQ) operation; operation code 7 indicates the TFTP Write Request (WRQ) operation.
Command processor identifier OUTPUT; BINARY(4) Indicates the command processor that you want the server to use for interpreting and running the command. The following values are valid: | | | | 0 | iSeries Control Language The server processes the command as an iSeries control language (CL) command. This is the default value. | | 1 | Qshell command The Qshell command interpreter processes the command. The server uses the spawn() application program interface (API) to call QShell as a child job.
| | | | | | If the Qshell Interpreter option of OS/400 is not installed, the REXEC client receives (in the stdout stream) a REXEC protocol diagnostic message that says “Qshell interpreter not installed”. v When you set the Command processor identifier parameter to 1 or 2: – The server maps the REXEC stdin, stderr, and stdout streams to file descriptors 0, 1, and 2, respectively. | | – The server sets the QIBM_USE_DESCRIPTOR_STDIO environment variable to Y.
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Notices This information was developed for products and services offered in the U.S.A. IBM may not offer the products, services, or features discussed in this document in other countries. Consult your local IBM representative for information on the products and services currently available in your area. Any reference to an IBM product, program, or service is not intended to state or imply that only that IBM product, program, or service may be used.
programs and other programs (including this one) and (ii) the mutual use of the information which has been exchanged, should contact: IBM Corporation Software Interoperability Coordinator 3605 Highway 52 N Rochester, MN 55901-7829 U.S.A. Such information may be available, subject to appropriate terms and conditions, including in some cases, payment of a fee.
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Index Special Characters *AIX format 51 *AS400 format 51 *BASE pool size 71 *IOSYSCFG authority 10 *NIC format 51 *SYSGEN default value 10, 76 (Transmission Control Protocol/Internet Protocol) attributes 16 A AA entry 76 Add TCP/IP Remote System Information (ADDTCPRSI) command 17 Add TCP/IP Route (ADDTCPRTE) command 14 adding default routes 15 TCP/IP remote system information 17 TCP/IP route 12 ADDTCPRSI (Add TCP/IP Remote System Information) command 17 ADDTCPRTE (Add TCP/IP Route) command 14 application e
dead gateway processing 55 default route adding 15 display TCP/IP connections 48 displaying system name and address 19 distributed data interface (DDI) fiber distributed data interface (FDDI) 2 shielded twisted pair distributed data interface (SDDI) 2 domain name 22 E End TCP/IP Connections (ENDTCPCNN) command 41 End TCP/IP Interfaces (ENDTCPIFC) command 36 ending interfaces, route-to-interface binding 36 TCP/IP connections 41 ENDTCPCNN (End TCP/IP Connections) command 41 ENDTCPIFC (End TCP/IP Interfaces)
N NETSTAT (Network Status) command 33 network interface types supported 75 Network Status (NETSTAT) command 33 network status for TCP/IP connections display 40, 48 display totals 49 end 40 general information 38 ending interfaces 36 interface display associated routes 44 work with configuration status 41 interface status display 43 work with 34 route information, display 37, 46 starting interfaces 35 work with 33 next hop 13 definition 13 Notices 93 P packet forwarding 16 Packet Internet Groper (PING) comm
TCP/IP (Transmission Control Protocol/Internet Protocol) (continued) QTSMTPSRVR 25 planning for installation and configuration 2 QSYSWRK subsystem 25 starting 24 TCP/IP Administration (TCPADM) menu 2 TCP/IP servers starting 24 TCPONLY parameter 73 Transmission Control Protocol/Internet Protocol (TCP/IP) attributes 16 interface entry 10 job description 71 QAPPCTCP 25 QSNMPSA 25 QTCPIP 25 QTFTPxxxxx 25 QTGTELNETS 25 QTLPDxxxxx 25 QTMSNMP 25 QTMSNMPRCV 25 QTSMTPBRCL 25 QTSMTPBRSR 25 QTSMTPCLNT 25 QTSMTPSRVR 25
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