Slow internet connection when I use a switch

bucovaina78 · 03-08-2009, 12:27 PM

This is my situation:

ADSL internet connection with wireless/LAN router. One LAN connection in my bedroom splitted with a USR7905 Ethernet switch, 3 computers attached on the switch. 2 of them are Ubuntu, one of them is a Packard Bell Dot with WINXP.

My ubuntu boxes are surfing really slowly but the packard bell windows laptop is going normally. If I pull out the ethernet switch and plug one of the ubuntu boxes into the wall my connection is perfect ???

So it's the combination with Ubuntu and the switch I guess?

tredegar · 03-08-2009, 12:48 PM

Do you have a lot of traffic on your LAN? If you unplug the win PC and one ubuntu PC, do things speed up on the remaining PC?

Is someone stealing bandwidth from your wireless connection?

Do you have IPV6 enabled? If so, you could try disabling it (you'll need to make these entries in /etc/modprobe.d/aliases

Code:

alias net-pf-10 off
alias ipv6 off

then reboot.)

If you are using firefox, you can turn off firefox trying to use IPV6 by going to

Code:

about:config

in the address bar, and then IPV6 in the search box then set network.dns.disableIPv6 to true

Any better?

lazlow · 03-08-2009, 01:11 PM

I would use ethtool to make sure you are running at 100 and not 10. It could be something as simple as a bad cable.

Quote:

[root@localhost ~]# ethtool eth0
Settings for eth0:
Supported ports: [ MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: MII
PHYAD: 9
Transceiver: external
Auto-negotiation: on
Supports Wake-on: g
Wake-on: d
Link detected: yes

bucovaina78 · 03-23-2009, 01:25 PM

Finally I (someone else

) solved the problem. I was wrong when i said the packard bell laptop was surfing fast. It doesn't ...

I told my problem to the IT-guy at my work. He told me to switch the speed/duplex on my windows laptop from auto negotiate, to 100base full duplex. That didn't work, but 10base full duplex works just fine.

My next questions? How do I switch my Ubuntu boxes to 10base full duplex?

tredegar · 03-23-2009, 02:52 PM

Quote:

How do I switch my Ubuntu boxes to 10base full duplex?

lazlow has already given you the answer: ethtool
Please read up on it.

bucovaina78 · 03-27-2009, 01:10 PM

ok, I didn't read that well I guess

to be complete I'll post what solved my problem:

Code:

sudo apt-get install ethtool
sudo ifconfig eth0 down
sudo ethtool -s eth0 eth0 duplex full speed 10 autoneg off
sudo ifconfig eth0 up

I don't know if it is nessecary to bring eth0 down, I just did it

And after a few months of slow internet on my Ubuntu box, I have no reason left to use my windows puter

haha