ITEM: I2646L

Problems pinging other RS/6000 machines from a brand new install.



Question:
I have a brand new RS/6000 model 365 running 3.2.5.  I have configured 
this machine on my ethernet network.  I have two other RS/6000 boxes and 
two non IBM Unix machines on this ethernet network.  The ethernet consists
of thick net.  These machines are able to ping each other, but can not ping
my new RS/6000 model 365 machine.  I am able to ping myself and I do have a 
current /etc/hosts file.  Why am I not able to ping the network?

ANS:   There are multiple reasons that you might not be able to ping the
network.  Some of the possible causes are bad cables, bad configuration,
integrated card not jumpered, incompleted /etc/hosts file, bad hardware.  
To determine what is causing the problem follow the steps below:

lssrc -g tcpip          -Verify that all necessary daemons are running, 
                         inetd must be running.  If the daemons need
                         to be started then type the command, 
startsrc -g tcpip

vi /etc/hosts           -Verify that this file is up to date and contains
                         a loopback entry.

127.0.0.1       loopback localhost              \# loopback (lo0) address

smitty tcpip            -Verify that the entries are correct.  Note
                         that the cable type should match the following
                         table.

Adapter       High Performance    Totally Integrated    Partially Integrated
Connectors      DIX and BNC            DIX only             DIX, BNC or UTP
10Base5            DIX                   N/A                   N/A
10Base2            BNC                   N/A                   N/A
10BaseT            DIX                   N/A                   N/A

netstat -i              -This command will give you information on what 
                         network interfaces that you have configured.  
                         Since you are only on a ethernet network you 
                         should have 4 entries.  You should have two 
                         entries for loopback and two entries for your 
                         ethernet network, ie en0.  This command showed 
                         that et0 was also configured.  This is not the 
                         type of of interface that you are using.  Note 
                         that your tcpip problems could be caused by this.  
                         The rest of your machines are configured with the 
                         interface en0 and this machine has both interfaces 
                         configured with the same IP address for each interface.
                         The en0 and et0 interfaces are not compatible since 
                         they both have different packet formats.  Remove the 
                         ent0 configuration and restart the tcpip daemons with 
                         the following commands:

ifconfig et0 down 
ifconfig et0 detach 
rmdev -l et0 -d
stopsrc -g tcpip
startsrc -g tcpip

                         Try to ping the machines on your network now.  If you 
                         are still unable to ping continue to the next step.

arp -a                   -this command will show the arp table.
                         The arp table is used to resolve the
                         software IP address to the hardware
                         address of the actual adapter.  This
                         hardware address is known as Media
                         Access Control (MAC) address.  
                         This command showed that the arp table 
                         had "incomplete" entries.  The table
                         showed the hostname and software address 
                         but not the hardware address of the
                         machine that was pinged.

hostname.fulldomain.name (192.9.200.5) at (incomplete)

                         The arp table can be set with;

arp  -s Type HostName Address

                         I do not think that this would help in this case 
                         since the machine does not seem to be able to send 
                         or receive any broadcasts on the network.  This could 
                         be caused by a loose cable, a bad adapter, or a bad 
                         cable.  Confirm that the cables are good and have good 
                         connections.  Check the error report to see if the 
                         adapter is reporting any problems.  This can be done 
                         with the following command;
errpt   

                         Note that since the machine is able to ping itself 
                         the adapter is more then likely functioning properly.
                         The loopback is used when the machine pings itself.  
                         If the hardware is correct and working properly then 
                         continue to next step.

lscfg -l ent0 -d         This command will give information on the
                         type of ethernet card that is in the
                         machine.  If only one line of information is
                         is shown then the card is a partially integrated
                         ethernet.  These type of cards have a jumper
                         that is set either for thick or thin.  
                                  
DEVICE          LCOATION                DESCIRPTION

ent0            00-01                   standard ethernet adapter

                         In the past if the jumper was not set properly an 
                         error message would be echoed on the console to 
                         check the jumper setting.  At 3.2.5 and above
                         this might no longer be the case.  Therefore it if 
                         the card is jumpered to the wrong cable type then 
                         you would not be able to send or receive broadcasts 
                         from the network.   If this is the case, the only 
                         way to change the cable type is by moving the jumpers 
                         on the riser card, a job that an IBM C.E. should 
                         perform if the RISC is under warranty.  There is no 
                         change in the software configuration for this card.  
                         Once the jumper is set correctly then reconfigure the 
                        interface via smit.

smit tcpip
   Minimum Configuration & Startup
      et0
  \

Try to ping.  If the RISC is still not able to ping the network then check
to make sure that there is not an alternate ethernet address set.

smit commodev
  Ethernet
    Adapters
      Change/Show
         ent0 
Verify that the ALTERNATE ETHERNET address option looks like:
  
     ALTERNATE ETHERNET address                         [0x]



Support Line: Problems pinging other RS/6000 machines from a brand new install. ITEM: I2646L
Dated: January 1995 Category: N/A
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