[CentOS] Centos hold me back from work - sshd ...bull

[Valeri Galtsev]

On Thu, April 28, 2016 11:25 am, Gordon Messmer wrote:
> On 04/28/2016 02:09 AM, Andreas Benzler wrote:
>> ine-imac-andy:~ andy$ ssh -vvvandy at 141.52.135.21
> ...
>> debug1: Enabling compatibility mode for protocol 2.0
>> write: Broken pipe
>> ine-imac-andy:~ andy$ ssh -vvvandy at 141.52.135.21
> ...
>> debug1: SSH2_MSG_SERVICE_REQUEST sent
>> ssh_packet_read: Connection reset by peer
>
>
> I see one possibility that explains both the key change and the
> connection resets:
>
> You installed a new server and used an IP address that was already in
> use on another server.  That's why you already had an SSH key for that
> address.  The connection resets occur when the client you're using to
> connect updates its ARP table and swaps from the MAC address on the new
> host to the MAC address on the old host (or visa versa).

Oh yes, and bizarre may happen if you have two machines with the same
static IP _simultaneously_ on the network. To check if that is the case
(for particular IP, say 192.168.2.7) from the machine with different IP on
the same subnet 192.168.2.x do

arping 192.168.2.7

you will get ARP responses from all machines, and if there is more than
one, you will see responces coming from different MAC addresses.

Valeri

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Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
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