wall command + broadcast message not appears on second cluster machine

Question

I have two cluster solaris machine ( machine1 , machine2 ) I have connection between two machines ping and ssh work fine ( cluster is fine )

 more /var/tmp/mesg
 TEST

I execute the following command:

    wall –a /var/tmp/mesg on machine1  ( on machine1 )

on machine 1 I see the message “TEST”

But when I check the message “TEST” also on machine2 , then I not see the message “TEST”

Please advice what chuld be the problem – on machine2 I not get the broadcast message “TEST”

details from machine1 and machine2

 machine1 - details


 [root@machine1 /var/tmp]#ifconfig -a


    lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1
    inet 127.0.0.1 netmask ff000000 
e1000g0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
    inet 10.20.24.137 netmask ffffff80 broadcast 10.20.24.255
    groupname Data_ipmp
    ether 0:21:28:d2:31:3e 
e1000g0:1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
    inet 10.20.24.141 netmask ffffff80 broadcast 10.20.24.255
nxge0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
    inet 0.0.0.0 netmask ff000000 broadcast 0.255.255.255
    groupname Data_ipmp
    ether 0:21:28:e1:1:aa


machine2 – details


[root@machine2 /var/tmp]# ifconfig -a
lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1
    inet 127.0.0.1 netmask ff000000 
e1000g0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
    inet 10.20.24.140 netmask ffffff80 broadcast 10.20.24.255
    groupname Data_ipmp
    ether 0:21:28:4f:e9:1e 
nxge0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
    inet 0.0.0.0 netmask ff000000 broadcast 0.255.255.255
    groupname Data_ipmp
    ether 0:21:28:e0:15:8a







netstat -rn

Routing Table: IPv4
Destination           Gateway           Flags  Ref     Use     Interface 
-------------------- -------------------- ----- ----- ---------- --------- 
default              10.20.24.129         UG        1          0           
10.20.24.128         10.20.24.137         U         1        160 e1000g0   
10.20.24.128         10.20.24.141         U         1          0 e1000g0:1 
224.0.0.0            10.20.24.137         U         1          0 e1000g0   
127.0.0.1            127.0.0.1            UH       40     373257 lo0

score 5 · Accepted Answer · answered May 18 '12 at 14:43

5

Working as Designed.

wall writes a message to the terminal of any user currently logged in to the local machine.
It has no concept of "cluster", and no ability to talk to other machines (and even if it did, having such behavior as the default would be highly undesirable in the majority of situations).

If you want to write a message to users on multiple machines you need to connect to each machine and broadcast the message (or use a messaging facility provided by your cluster software, if such a facility exists).

answered May 18 '12 at 14:43

voretaq7

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but the two machines are connected ( i Have ping and ssh and no network problem - so why wall not send msg to other terminal machine ? – Eytan May 18 '12 at 15:38
@Eytan because **That's not how `wall` works**. A *terminal* (in the context of how `wall` defines it) is a **tty device connected to the local machine**. See also MikeyB's answer describing `rwall`, which is the *right* tool to do what you're trying to accomplish (provided you specify which machines you want it to talk to...) – voretaq7 May 18 '12 at 17:10

score 3 · Answer 2 · answered May 18 '12 at 14:54

You're probably thinking of the rwall service.

Description

The rwall command sends messages to all users on the network. To do this, the rwall command reads a message from standard input until it reaches an end-of-file character. The rwall command takes this message, which begins with the line Broadcast Message..., and broadcasts it to all users logged in to the specified host machines. Users receive messages only if they are running the rwalld daemon, which is started by the inetd daemon.

Note: The time out is fairly short. This enables the rwall command to send messages to a large group of machines (some of which may be down) in a reasonable amount of time. Thus the message may not get through to a heavily loaded machine.

wall command + broadcast message not appears on second cluster machine

2 Answers2