[plug] Network query

[Bret Busby]

Hello, all.

A LAN is as follows:


    Server/firewall/gateway
             |
             |
   _____________________
   |         |         |
   |         |         |
Client1   Client2   Client3


The server is running RH 6.2, Client1 is running RH 6.2, Client2 is 
running RH 7.3, and Client 3 is running Debian (testing).

The server is shutdown at night (dodgy power supply/fan), and Client2 is 
left running overnight. Client1 and Client3 are not running.

This procedure is done over a number of nights, without any problem. 
Then, due to a decreasing free disk space on the server, archived log 
files (*.<x>.gz) are deleted from /var/log, on the server.

Then, the server/firewall/gateway is connected to the Internet (as it 
is, almost each day), and fetchmail downloads email messages which are 
sorted by postfix, in to mailboxes.

Then, using Client2, user tries to access mail (using PINE) on server, 
as is usual. Attempt fails.

User tries to ping server from Client2. Destination host unreachable. 
User tries to ping Client2 from server. Destination host unreachable. 
User pings server from server, and, Client2 from Client2; pings are 
successful for pinging same machine. User boots up Client1, and tries to 
ping Client2 then server, from Client1, and tries to ping Client1 from 
Server then from Client2. Destination Host unreachable in each case. 
User pings Client1 from Client1; pings are successful for pinging same 
machine. User "jiggles connections at network cards", to find whether it 
makes any difference. No difference. User boots up Client3, and pings 
server. Client 3 successfully pings server, and then server successfully 
pings Client3. User then pings Client2 from Client3, then pings Client3 
from Client 2, and server from Client2 and Client2 from server. pings 
are each successful. Client1 ping is similarly "awoken". Client3 is 
shutdown, and pings between remaining live computers, are successful, 
each way.

This all happened within the last couple of hours.

Any ideas as to what has happened, and why?

Thanks in anticipation.

-- 
Bret Busby
Armadale
West Australia
..............

"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
  Chapter 28 of 
  "The Hitchhiker's Guide to the Galaxy:
  A Trilogy In Four Parts",
  written by Douglas Adams, 
  published by Pan Books, 1992 
....................................................

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