ITEM: F2393L

Can't use 'talk' command on system not attached to network.


We are at 3.2.X. I'm trying to use the talk command on a system that
is not connected to a network.  The system has no network adapters of
any kind.  When I try to use the command, I get the message:

error on write to talk daemon: no route to host

We tried the following:

We could not ping ourself (SLIP interface). 
The /etc/hosts file was correct.  
The ip address is 
Vi the /etc/inetd.conf and uncomment the talk line.  
Issue 'inetimp' and then 'refresh -s inedt'. 
host 'hostname' returns the proper name and ip address.

This didn't change the problem.
The error we're getting refers to the system being down.


Infoexplorer on the command says for two users on a standalone
machine, they should use

talk user1@loopback [Tty] [Pty]

to which user1 responds,

talk user2@loopback [Tty] [Pty]

I was telnet'd out to another machine, telnet'd back to my machine and
logged in.  No problem talking from root to user, just

root> talk user@loopback

user> talk root@loopback


To send messages from one user to another user on a system that is not
connected to a network and does not have a network adapter, you should
use the "wall" or the "write" command.  If you must use the "talk"
command, you should be aware that this will not be a supported
configuration, and that the "talk" command was not designed to be used
this way.

You can force "talk" to work by doing the following:

1)  Create a SLIP interface.          
        - The addresses can be anything. ( ->

2)  Name the local host (          
        - 'hostname mickey'

3)  Create a static route from ->          
        - smitty
              further configuration               
                static routes
                  add a static route

                             Add Static Route
                                                        [Entry Fields]
  Destination TYPE                                     host           + 
* DESTINATION Address                                  []
  (dotted decimal or symbolic name) 
* Default GATEWAY Address                              []
  (dotted decimal or symbolic name) 
* METRIC (number of hops to destination gateway)       [1]

4)  Check your host's route table.          
        - smitty tcpip
            further configuration
              static routes
                list all routes       UGH     ...     lo0         UH      ...     sl0
        127          U       ...     lo0

5)  Make sure your loopback interface is up.          
        - ifconfig lo0

lo0: flags=b\
        inet netmask 0xff000000 broadcast

6)  Make sure the proper entries are in your /etc/hosts file.
        - cat /etc/hosts              loopback localhost      \# loopback (lo0) name/address                mickey

7)  You should now be able to use the following commands and syntaxes:
        - talk \         
        - talk \@loopback         
        - talk \@mickey         
        - All uses of the "!" and ":" should also function.

By setting the route for the SLIP interface address of to which is the address of the local loopback, we have fooled
the system into thinking that it has a network interface connected to
an active network.  All talk requests use the hostname of the system,
and the hostname must resolve to an active address.  Be aware that
this internal routeing may effect other things on the system, like
mail, which use the local loopback address to talk to local daemons.
While this may be dangerous, it is much better than binding your
system name to the local loopback address or nameing your system
"loopback" which also works.


In addition to the above steps, we also had to remove 
the file /etc/resolv.conf.

Support Line: Can't use 'talk' command on system not attached to network. ITEM: F2393L
Dated: December 1993 Category: N/A
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