Strange Overload Issue on Network

SUSE Linux Enterprise Server SLES Networking
1

Hello,

There are several customers of ours using SLES under database servers and for a few weeks their network connections have been crashing while server machines which SLES installed on in the same lan. Every customer has one server machine in their LAN. (Individual customers + individual LANs + individual internet routers etc.)

If server machine is not in the lan everything goes well but when we switch it to the network it causes a network overload and internet connection reduces by almost 99%.

Is there any action you would suggest us to perform in order to determine a proper solution for this problem.

Thank you in avance for your support!

Regards,

2

hgunen,

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3

On 06/16/2014 02:34 AM, hgunen wrote:[color=blue]

There are several customers of ours using SLES under database servers
and for a few weeks their network connections have been crashing while
server machines which SLES installed on in the same lan. Every customer
has one server machine in their LAN. (Individual customers + individual
LANs + individual internet routers etc.)[/color]

Customers all over the world are using SLES as hosts for DBs as well as
other services, many on shared networks. The chance of one server somehow
causing another server’s network connection to “crash” is pretty small,
and without a lot of evidence I’d bet this is coincidental.
[color=blue]

If server machine is not in the lan everything goes well but when we
switch it to the network it causes a network overload and internet
connection reduces by almost 99%.[/color]

Oh, the network isn’t crashing, it’s just overloaded? What’s happening on
the network to cause it to be overloaded? Get/Post a LAN trace from the
router/switch that services these machines.
[color=blue]

Is there any action you would suggest us to perform in order to
determine a proper solution for this problem.[/color]

Determine what “overloaded” means in specific terms. SLES servers are
used all over the world, on both fast and slow networks. Unless something
is installed on them to take down a connection the chances of there mere
existence doing this is really, really small.

–
Good luck.

If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…

4

[QUOTE=ab;22119]On 06/16/2014 02:34 AM, hgunen wrote:[color=blue]

There are several customers of ours using SLES under database servers
and for a few weeks their network connections have been crashing while
server machines which SLES installed on in the same lan. Every customer
has one server machine in their LAN. (Individual customers + individual
LANs + individual internet routers etc.)[/color]

Customers all over the world are using SLES as hosts for DBs as well as
other services, many on shared networks. The chance of one server somehow
causing another server’s network connection to “crash” is pretty small,
and without a lot of evidence I’d bet this is coincidental.
[color=blue]

If server machine is not in the lan everything goes well but when we
switch it to the network it causes a network overload and internet
connection reduces by almost 99%.[/color]

Oh, the network isn’t crashing, it’s just overloaded? What’s happening on
the network to cause it to be overloaded? Get/Post a LAN trace from the
router/switch that services these machines.
[color=blue]

Is there any action you would suggest us to perform in order to
determine a proper solution for this problem.[/color]

Determine what “overloaded” means in specific terms. SLES servers are
used all over the world, on both fast and slow networks. Unless something
is installed on them to take down a connection the chances of there mere
existence doing this is really, really small.

–
Good luck.

If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…[/QUOTE]

Hi ab,

Firstly, I have greatly appreaciated your informative and helpful response to this thread. To find out what causes the problem we face, your reply forced me to go deeper on some of the servers which we struggled with that overload/outage issue, I googled and have seen that someones are having the same problem.

There are some malware, IptabLex & IptabLes that was put onto the servers and wrote themselves in /boot and /usr.

The infected servers flooded and crashed the networks which they are on because the malware ping and send data to some destinations located in China and some of are in Japan.

Well, I removed the malware from our customers’ servers but according to the information I got from the Internet, those servers are likely to get infected again.

Now I am working on making our servers much safer than the currents.

Thank you!

Regards,