Bug 20441

Command executed on system "dndsd4" RH7.0 to remote system "dndsd3" RH6.2:

# rexec dndsd4 date

<Hostname>: Connection refused
rexec: Error in rexec system call
rexec: The following system error may itself be in error
rexec: Connection refused.

I tried the same command on a RH6.2 and it works just fine. I moved 
the /usr/bin/rexec executable to the RH7.0 system and that works fine on 
the RH6.2 system but fails on the RH7.0 system. I used strace to trace 
both situations:

1) rexec from RH7.0 to RH6.2 => Good trace

2) rexec from RH6.2 to RH7.0 => Bad trace


rexec command trace analysis
============================

strace shows initiation of a connection on a socket fails because of a bad 
destination socket number parameter for connect() function for rexec 
command.


From rexec good trace (rexec RH6.2 to RH7.0)
============================================

dndsd3                                   dndsd4
[RH6.2] <---- rexec dndsd3 date ------> [RH7.0]


I'm showing only two lines of trace produced from:
"strace -v rexec dndsd3 date"

... trace clipped...

socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3
connect(3, {sin_family=AF_INET, sin_port=htons(512), sin_addr=inet_addr
("15.114.20.110")}}, 16) = 0
...

where input parameters for connect() function are: 

1) file descriptor to a socket = 3

2) socket address data structure for destination address =
 	{sin_family=AF_INET, sin_port=htons(512), sin_addr=inet_addr
("15.114.21.111")}}

3) address length = 16


From rexec bad trace (rexec RH7.0 to RH6.2)
===========================================

dndsd4                                   dndsd3
[RH7.0] <---- rexec dndsd3 date ------> [RH6.2]

I'm showing only two lines of trace produced from:
"strace -v rexec dndsd4 date"

.... trace clipped...

socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3
connect(3, {sin_family=AF_INET, sin_port=htons(2), sin_addr=inet_addr
("15.114.21.112")}}, 16) = -1 ECONNREFUSED (Connection refused)
....

Return value for connect() shows: ECONNREFUSED (No one listening on remote 
address)

The above shows that the problem lies with NOT getting a good end-point 
with a good destination socket number on RH7.0.

Is this a problem with RH7.0 rexec or is it a problem with the network 
stack on RH7.0 since I've moved the RH7.0 /usr/bin/rexec executable onto a 
RH6.2 system and it works just fine in RH6.2 environment.