Wird Fedora Problem

[QatQat]

Hi everybody,

I am experiencing a very weird behavior from a Fedora 8 box.

It stops loading internet pages before they are complete. Sometimes it will display a simple page, but when a complex and heavier page is called it will only display the beginning of the page and then keep on waiting without even giving an error.

Network is working with all other boxes, just this one behaves like I described above.

I can connect to the box from the Internet via SSH, FTP etc.. but the speed is incredibly slow.

Named is turned off;
address is assigned via DHCP server;
kernel updated to 2.6.24-5.85.i686 as somebody on the net experienced same problem and fixed it with a kernel upgrade; I updated it but no joy.
Tryed to load older 2.6.23 kernel as well. no luck either.

I assume it is a kernel problem as this box is the host for a VMWare server; guests OS on the server behave the same so something around the networking of the host is serioulsy gone weird.

Any idea?



QatQat


If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[QatQat]

MOre info:

I have tried a second network card with no results.
Out of desperation I have re-installed Fedora but still nothing happening.

I have tried to load a live distro but behaves the same.

Could it be some kind of ARP problem?

MAC addresses on the routers are correctly registered, but it really looks like ARP problem at this point.

What other test can I do?

QaTQat

If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[elgrandeperro]

Check your switch speed and negotiation. That would not be fixed by switching network cards.

 

[QatQat]

Hi elgrandeperro,

switch is a non-managed one. SO no way of getting info on ARP cache there.

Ethtool reports that the PC's NIC negotiatio is set on auto and the link is correctly assigned as 100Mbit/s
DUplex is full (not very relevant for ARP problems anyway).

A bit more info on the configuration of the network.

The machine affected by this connects to a router with 192.168.0.1 address.

That router routes the machine (and other machines on the same subnet) to the external router. External router is 192.168.1.1

All PCs on 192.168.0.0 behave perfectly; some run linux, some run FreeBSD, one windoz server also works well.

Only this box gives problems as described above; even running Live distros, it only loads partial pages.

It works instead perfectly on internal addresses. Both normal network traffic and internet traffic on internal web servers go normally and pages of the internal Intranet load perfectly.

Routed internet traffic from outside stops after a few bytes. Routers are obviously fine otherwise other PCs would not connect.

ARP entry on 192.168.0.1 router shows correct match between MAC address and ip address of the machine (192.168.0.10).

Any other suggestion?

QatQat

If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[Annihilannic]

A shot in the dark, but try adjusting the MTU size perhaps?

Annihilannic.

 

[QatQat]

Hi Annihilannic,

you gave me a bit of hope.

I found out, in fact, that MTU of my Provider is lower than the one my 192.168.0.1 router was negotiating.

I have aligned the two but the problem persists.

Thanks for the try anyway.

This is the first time, I must admit, that I cannot see other solution than buying a new PC.

Can the motherboard have something to do with it? And if yes, why only when I visit Internet sites and not Intranet?

QatQat


If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[Annihilannic]

Try lowering the MTU again so that it is lower than your provider's, that way any headers or trailers that are added to it on your network should be acommodated. What size is it by the way?

It definitely sounds like something networky to me, but the symptoms sure are strange! What did you mean exactly by "I have tried to load a live distro but behaves the same."? did that involve booting into a completely different OS, like Knoppix?

Annihilannic.

 

[QatQat]

That's correct.

I even re-installed Fedora completely.
So it must be definitely something hardware/netowrk related.


MTU recommended by provider is quite low 1400.
My router defaults to 1500, not even the standard 1492.

Anyway, I will try to lower it < 1400.

What are the implications of a too low MTU by the way?

QatQat

If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[QatQat]

and Yes I also tried live distro (Ubunbtu).

I lowered MTU to 1300 but no difference.

Today it definitely loads lages more than what it did yesterday. most pages arrive to almost 80%.

What the hell is going on? I have not changed anything since yesterday and today, even with MTU back to original settings, it has improved.

I think the PC is slowly remembering how to use the internet (I have nothing else to do than laugh at it.).

QaTQat

If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[Annihilannic]

Freaky.

See the first paragraph here for the implications of changing MTU:

http://en.wikipedia.org/wiki/Maximum_transmission_unit

Annihilannic.

 

[QatQat]

Thanks for link,
so higher is better. I have 20Mbit/s line so it should definitely be high.

QatQat

If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[geirendre]

You can also try and use a network sniffer like wireshark
and see if you can find any info in the traffic on your
system that can reveale what happens.
Wireshark should be available in the repositories.

HTH

 

[elgrandeperro]

Check "netstat -in".
ARP, BTW has nothing to do with this. The only ARP (to external) is to the default router, and it is getting that from cache.

Possible to switch ports on your switch?
And are you doing any "funny" things to get redundancy, like
multiple default routes?

 

[QatQat]

Hi Elgrandeperro,

I am away from the office for a few days.

Will try that and post the output.

In the meantime, thanks to all of you for your suggestions.


QatQat

If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[QatQat]

Hi all,

I have finally decided to call the provider.
Technician advised to try and establish connection using normal adsl-setup suite.

It worked after that; so they will send a new router. What I do not understand is why all other machines worked fine.

I am sure that new router won't solve the problem but at least I now know that connecting through ppp0 will work fine. Cheap solution but better than unusable internet.


Thanks all for your time, and if anybody can make any sense of this last development, please any suggestion is welcome.

QatQat

If I could have sex each time I reboot my server, I would definitely prefer Windoz over Linux!

 

[danomac]

Have you tried changing/checking the network cable? I had a similar problem with a linux server. Internal sites seemed to be fine (maybe because the latency is lower?) It turned out there was a badly crimped end. I was actually trying to download updates when I found out it was acting up - the server runs bind+dhcp and was running on the internal LAN just fine!

It really makes me wonder as all the guest OS installs are acting that way.

Total shot in the dark here.