Re: Dell-Oracle-Linux: Anyone else run this...because its not working for us!

From: 時期精霊 <kuon_at_goyman.com>
Date: Tue, 22 Nov 2005 22:03:24 +0100
Message-ID: <4383879C.8020205@goyman.com>

Rodd Holman wrote:
> Henry,
> I can't answer much to what flakiness you are observing, but you are
> correct in your assumption about direct connect. You need the crossover
> cable so that tx goes to rcv and vise-verse. You'll get a network cable
> unplugged error if you try to direct connect two servers with a straight
> pass through cable.
>
> Rodd
>
> Henry Poras wrote:
>

>> OK, time to demonstate some network ignorance. Our SA says we have 
>> straight
>> through ethernet cables, not crossover (switch has been ordered, just not
>> here yet). From what I can tell, crossover cables are needed to 
>> connect same
>> devices so the transmit pin from one connects to the receive pin of the
>> other device. If so, shouldn't server to server direct connections use
>> crossover? Would straight through work at all? If they both worked, I am
>> assuming the network flakiness would be observed in either direct connect
>> and a switch would always be necessary. Correct?
>>
>> Henry
>>
>>

Some nic now have auto crossover detection, then a straight cable will work. Otherwise, just google on crossover rj45 cable.

But you should not use crossover cable for servers, you will have the following problems:

Server a will have network down if server b reboot. This can be bad in many situation.
Some OS can do weird auto detect stuff (like windows), I never read to much about windows network detection, but you can have infinite loop (up down up down...).
Some gigabit ethernet nic will fail if you use a crossover cable. (they use 8 pin)
Perhaps something else:)

And having a switch give you the folowing advantages:

- Statistics ability.
- More than two servers.
- Security management. (sometimes you might need to cut the link for any

reason, but often security, and being able to type a command is far more convenient than running to the datacenter) - Only things in my head right now.

Regards

Kuon

--
http://www.freelists.org/webpage/oracle-l

Received on Tue Nov 22 2005 - 15:48:09 CST