Ref: 11020036
Title: Troubleshooting 3+Open TCP
Date: 5/3/91

Copyright 3Com Corporation, 1991.  All rights reserved.

Supporting a network requires a great deal of knowledge about all the
parts of the network, from the cabling to the software applications.
If there is a problem on the network, it can be difficult to know what
information you need to solve it.  Following are questions that 3Com
Technical Services uses to troubleshoot networks with 3+Open TCP.  You
can use these questions to assist in your own troubleshooting or when
preparing to call 3Com Technical Services.

Also have a copy of the PROTOCOL.INI file available for review.


HOST CONNECTIVITY

1.  What product is used for host connectivity?  3+Open TCP? 3VT? FTP?

2.  What type of third-party emulator is being used?

3.  If connecting to a Comm Server, what type of flow control is used?

4.  What type of host?

5.  How is workstation connected to host?  modem? gateway? bridge? router?

6.  Is the workstation on the same wire as the network?

7.  If workstation is locking up, can the session be reconnected?

8.  What commands are being executed at the workstation?

9.  What commands are being executed during the host session?


TROUBLESHOOTING 3+OPEN TCP

To verify that the addresses of the host nodes are correct, load tcptsr,
dnrtsr, and nmtsr only and then ping an address or host:

   ping <ip address> | <host name>

If you get a response, your addresses are correct for configuration and
cabling.  You might see

   No response from 123.123.123.123

If you can ping but still cannot connect, take a LAN packet-level trace.

The program NMTSR.EXE shows the configuration of the workstation.  You can
tell if an attempt to logon was successful, or if a router was found.

1.  Load TCPTSR.EXE
2.  Load NMTSR.EXE
3.  Type netstat -a


You will get a readout that looks like the following sample:

TCP/IP Protocol Driver Configuration:

TCP/IP Driver Version     1.0
NetMan Driver Version     1.0
Internet Address          129.213.33.19
Subnet Mask               255.255.252.0
Physical Address          02:60:8C:0B:61:35

TCP Statistics:

Minimum retransmission timeout (msec)                            18
Maximum retransmission timeout (msec)                         19392
Maximum number of connections                                     8
Number of active TCP Opens                                        0
Number of passive TCP Opens                                       0
Number of connection attempts failed                              0
Number of TCP connection resets                                   0
Number of current connections                                     0
Number of segments received                                       0
Number of segments sent                                           0
Number of segments re-transmitted                                 0

TCP Connection Information:

Local IP Address/Port      Remote IP Address/Port      Connection State

    ** no entries **

UDP Statistics:

Total inbound UDP datagrams delivered to UDP users                0
Total inbound UDP packets with no receiving application           0
Total inbound UDP packets dropped for lack of resources           0
Total outbound UDP datagrams sent from this station               0

IP/ICMP Statistics:

Total IP datagrams received                                       2
Inbound datagrams dropped due to IP header errors                 0
Inbound datagrams dropped due to invalid dest address             0
Inbound datagrams dropped due to unknown protocol                 0
Inbound datagrams dropped due to lack of resources                0
Inbound datagrams successfully delivered to users                 0
Inbound datagrams forwarded to another station                    0
Total outbound IP datagram requests                               0
Outbound IP datagrams dropped due to lack of resources            0
Outbound IP datagrams dropped due to no route found               0
Maximum time to hold fragments for re-assembly (secs)            15
Number of IP fragments received                                   0
Number of IP datagrams successfully re-assembled                  0
Number of failures detected by IP re-assembly algorithm           0
Number of ICMP Destination Unreachable msgs received              0
Number of ICMP Source Quench messages received                    0
Number of ICMP Destination Unreachable messages sent              0
Number of ICMP Source Quench messages sent                        0

ARP

3Com TCP/IP Network Maintenance Facility v1.0
Copyright (C) 3Com Corporation, 1989.  All rights reserved.
Usage:  arp hostname     displays the host's ARP entry
        arp IP-address   displays the host's ARP entry
        arp -a           displays all ARP entries
        arp -c           clears the ARP table
        arp              displays this usage message



To find out if the Domain Name Resolver is loaded, type

   arp XXX.XXX.XXX.XXX

(For XXX.XXX.XXX.XXX, substitute the host's IP address.)

You might see:

   NMF1012: Domain name resolver not loaded.
                 or
   No ARP entry for 129.213.33.25    (which also means the DNR is not loaded)

Note:  You do not need the Domain Name Resolver if you are connecting with
the IP address.
