server goes offline and online back offline. etc....

[LordGarfield]

Hi,

somethimes my server does something verry strange.
It goes offline and online in some kind off loop.

If I restart my server everything is ok.

my server is connected to a router where all servers are connected to. and somethimes my other server has the same problem. they are both win2000 server family.

The problem first came when I did a manual back up of navision attain. then both servers went offline after a few seconds again online. then offline again etc..

Today only my mail server did this. All the others where fine. Nothing special whas happening at that time.

What could cause this problem?

best regards.


tank you,

(>" "<)
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LORD_GARFIELD
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[NoWittyName]

had this myself when a new switch had been installed, not all servers experienced this and some did even though they were not directly connected to the switch.

Master of Disaster.....Recovery

 

[fs483]

Have you checked for viruses. Anything else changed other than the manual backup ? Power fluctuations... Bad network cable, bad switch...

 

[LordGarfield]

yep I checked for viruses. I would say is is a bad NIC but somethimes another server has the same problem but they do not have it on the same time..


Is it possible that the switch where the servers are connected to becomes overloaded on a certain port and that this could cause the problem on the overloaded port?

tank you,

(>" "<)
(='o'=)
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LORD_GARFIELD
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[trusted]

It could be that your switch does not have the internal bandwith (switching fabric)to handle the load. What size is your network? What type of switches are you using?

 

[SGTRawlins]

We had simmilar issues on out serers, it turned out to be a bandwidth issue. install some sniffer software to monitor transfer activities.

 

[LordGarfield]

hi,

we have a actualy 2 buildings. one building is connected with fiber optic cable to the other and with a simple convertor it it plugged in in a small switch.
On the other end of the fiber optic it is connected to a 3com switch and about 10 pc and 2 printers are on it.

starting back from this small switch.
except for the fiber there are 3 servers on it. mailserver + domain controller, printserver and navision server.

the infrastructure of the building where this server room is in is connected to 2 24 port switches. they are connected toghetter and one of them is then connected to this small swith.

everything is 100mbit.

at last this small swith is connected to a us robotics broadband router for internet connection.

Would it solve the problem if we change the small switch with a better one?

best regards.

tank you,

(>" "<)
(='o'=)
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LORD_GARFIELD
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[fs483]

It's worth a try !

 

[dearingkr]

If your switches have the feature, make sure Spanning Tree protocol is disabled.

This can cause switch ports to go into 'Listening' mode which temporarily blocks traffic.

MCSE CCNA CCDA

 

[dkediger]

From your description, it sounds like this "small" switch is the backbone switch of your network?

IOW: You have connected to this switch:
3 servers - Including a SQL database server (Navision),
Broadband connection,
A stack of 2 switches that serve 48 ports,
A fiber connection to other building that serves 12 devices.

What brand/model is this "small" switch?

If the description above is correct, any/all packets on your network must pass through that "small" switch. Let us know what brand/model switch this is, but I'm betting its a big portion of your problem.

 

[LordGarfield]

hi..

tanks for the answers.

Yep I know it is allot for this small switch. And it goes even futher. the small swith has a blanco brand. the only words on it are "Fast-switch". witch means it is 100mbit. It is probably way to bad to serve as a backbone switch. That is why I'm suspecting this will be the problem.

But I need some oppinions. i can not go to the shop and buy another 3com switch wich are expensive and then see that this has nothing to do with it or doesn't do anything at all.

best regards

tank you,

(>" "<)
(='o'=)
-(,,)-(,,)------------------------------
LORD_GARFIELD
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[zebratech]

Is it a "smart" switch? Does it have software to monitor port traffic loads? If not you can prove out the problem by sniffing.

 

[LordGarfield]

It is powered so it's probably a smart switch but there is no software monitor for it.

I found out that it has almost no buffer and it has a verry low back plane. Whatever that means.

tank you,

(>" "<)
(='o'=)
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LORD_GARFIELD
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