Transcript TCP/IP Management

TCP/IP Management
GO TCPADM
TCP/IP Management
• Using the TCP/IP management tools to keep TCP/IP
on your AS/400 robust, reliable and effective.
• Each option of the menu GO TCPADM has an
associated command.
GO TCPADM
GO CFGTCP
CFGTCPAPP
STRTCP
ENDTCP
STRTCPSVR
ENDTCPSVR
WRKTCPSTS=NETSTAT
VFYTCPCNN=PING
STRTCPFTP
STRTCPTELN
SNDTCPSPLF
WRKSBSJOB
The components of TCP/IP
processing on the AS/400 include:
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The TCP/IP jobs
The physical connection over the line
The logical connection to the network
Optional SNMP services
TCP/IP Jobs
• One of the jobs that is running named QTCPIP is the
controlling TCP/IP job.
• Other jobs such as QTFTP*****, QTGTELNETS,
QTSMTP*****, QTWSG*****, QTLPD*****, QTPO***** ,
QTHTT***** also executed in QSYSWRK depending
on your configuration.
The jobs that accompany QTCPIP
are started in two ways:
• Automatically, when the STRTCP is issued
• Manually, through the use of the STRTCPSVR
• TCP/IP functions that can be autostarted are
FTP, Telnet, SMTP, LPD, HTTP, WSG ,POP.
• STRTCPSVR : options for the SERVER
parameter are *SNMP , *TELNET, * FTP ,
*SMTP, *LPD, *HTTP, *WSG , *POP
GO TCPADM
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WRKCFGSTS
To check the status of resources
VRYCFG
To specify the names of the configuration objects to be varied on or off.
PING
To confirm network connections and configuration
NETSTAT = WRKTCPSTS
To display network status ( *IFC *RTE *CNN )
DSPMSG MSGQ(QTCP)
DSPLOG LOG(QHST)
WRKSBSJOB(QSYSWRK)
PING
• Can help find problems in logical connections
• If the connection is successful ,receives a return reply.
• If the packet never returns, there is no route from the
source to the destination system and back again. This
does not mean that TCP/IP is not configured correctly;
it may mean that the routing is not established properly.
• If the packet does make a successful round trip, the
time that it takes to make the round trip may be
excessive. You may need to examine your network for
potential performance or bottleneck problem
VFYTCPCNN
• After configuring a system for TCP/IP communications
,use PING command to ping the address ( or name) of
the newly configured system.
• A successful PING doesn’t necessarily indicate that the
system is properly configured to communicate in the
network (routing and DNS issues may remain), but it
does indicate the TCP/IP protocol is loaded properly.
NETSTAT/WRKTCPSTS
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The network status you can view are
TCP/IP interface status
*IFC
TCP/IP route information *RTE
TCP/IP connection status *CNN
TCP/IP interface status
• This display shows the interfaces currently configured
on the system, including the loopback interface.
• The interface status are: Active, Inactive, Ending,
Failed ,Starting ,RCYPND, RCYCNL
• It’s a good idea to print the interface status fro
documentation purpose.
TCP/IP Route Information
• The route destination
• The subnet mask of the destination network
,sunnetwork, or system
• The next hop IP address
• A route available indication
*yes --- the router is active and available
*no --- the router is not available ,possibly due to an
inactive interface or a nonfunctioning router.
TCP/IP Route Information
• The Route Information detail display is valuable for determining
whether a route exists in the AS/400 routing table.
• For instance, PING is unsuccessful , you can examine the
routing table to determine whether a route exists to the remote
system .If the route is available, the problem might be in the
TCP/IP configuration of the remote system, the routing on the
remote system, or invalid routing information . If the route is not
available, direct your attention to the routers and lines in the
network that are logically between the source and the
destination systems.
TCP/IP connection status
• Listen--- the AS/400 is listening at the local port for an
incoming connection
• Established--- the connection is established and the
system are communicating
• Closed --- the connection has ended
• Other states may be seen during a transition period
• The ports( both remote and local) can use well-known
names rather than a port number. These names are
defined in the service table modified by the command
WRKSRVTBLE
TCP/IP connection details
• The number of bytes in and out ( from AS/400
perspective) for this connection.
• The retransmission information gives the number of
segments retransmitted by the AS/400 due to an
acknowledgement not being received.
• If the number of retransmission is higher than the
number that has been historically present for this
connection, it could be an indication that there are
network problems.
TCP/IP connection details
• The send window information identifies the current and
largest size of the send window, or the number of bytes
that can be transmitted without an acknowledgment.
• A large send window indicates that the network is
successfully transmitting large packets without the
need for retransmission.
• A small send window size means that the system has
detected problems and has reduced the window size in
an attempt to reduce the number of retransmissions.
Trouble Shooting
• If the TCP/IP services you want to enable are not
functioning
Solution: Check QSYSWRK---- make sure the
appropriate job is running in this subsystem
Trouble Shooting
• If a server process has been running but no
longer functions and cannot be seen when
WRKSBSJOB QSYSWRK
• Solution: Check the joblog for the missing
process. By default joblogs go to the output queue
QEZJOBLOG
Trouble Shooting
• If you got physical connection problem
• Solution: WRKCFGSTS ---- make sure
*LIN, *CTL , *DEV are all in ACTIVE
status. That enables communications
across a line and start the QTCPIP job and
associating the job with the line.
Trouble Shooting
• If you got logical connection problem
• Solution:
PING VFYTCPCNN
If the connection is successful ,you can receive a
return reply
NETSTATWRKTCPSTS
Trouble Shooting
• If the connection is active and data is
being transferred, F5 to refresh the
screen should show a change in the byte
counts. Otherwise probably means a
recently broken connection, a network
problem or a problem at the remote
system.
AS/400 database—DB2
STRSQL
CREATE
INSERT
UPDATE
SELECT
DELETE
ALTER
DROP