[SOLVED] noob getting slow downloads

[spazdaddy]

I am a very inexperienced Linux user in the process of emancipating myself from Redmond. I am running a dual boot with Ubuntu 10.04 and vista. Anyway both systems are very healthy as far as I can see. I have a very fast internet connection at 50Mbs. Under vista I can pull around 4 - 5MBs where under Ubuntu I can only get about 350KBs. I have a single PC hard wired into a Netgear WNR3500 router/firewall. Anyway, I was wondering if there is anything I can do with my packet sizes or receive windows to help it along? I am only using a very small part of my available bandwidth obviously. Is there a kind soul here who could tell me how to optimize my internet connection in Lucid? Any assistance would be very appreciated, thanks.

[oz]

I don't know if it will help in your case but some users get much better download speeds under Linux by disabling IPv6, so you might want to try it if you haven't done so already:

https://help.ubuntu.com/community/We...ngSlowIPv6IPv4

[spazdaddy]

Thank you, the article describes the symptoms perfectly. My router setup interface was getting kind of goofy and saying "no internet connection available, please run setup" while I was checking for new firmware - first time its ever done that, mind you I was online at the time hahah. I will see if it solves the prob.

[oz]

If you are running Firefox, you can test the situation quickly by going to about:config and entering IPv6 into the filter, then disabling it within Firefox. If that helps your speed issues with Firefox, you might want to consider disabling IPv6 on a system-wide basis.

[spazdaddy]

Well, it sounded like that could be it but "lsmod | grep inet6" produced no output and network.dns.disableIPv6 is set to true in FF. So it sounds like it's disabled on both systems.
I've always kept ipv6 disabled inside of vista.
However if I attempt to enter my router setup from FF while using Lucid it does indeed seem to exhibit "broken" behavior (the connection seems to stutter and sometimes drops)and I have to do a power cycle with the router to get it happy again. I've had no such probs under vista which is officially supported by my ISP, grrrr. I will off course avoid using the router interface while using Linux for the time being. (the connection will at least remains stable even if relatively slow)
I'd be pulling my hair out if I could.

[Kloschüssel]

I don't know if you're still searching for a solution, but have you some kind of QoS (Quality of Service) activated on your router device? And second, would you please post the output of:

iptables --list

[spazdaddy]

Hey thanks! Actually I got it sorted out finally. I wish I could retrace the steps I took exactly but it came down to getting the firewall set up properly for this machine. Being a paranoid windows alumni and pretty Linux stupid I was hobbling the system myself. NOTHING wrong with Ubuntu! I can't get quite the downstream I was getting under winders vista but I was able to get about a 250% increase with 0 packet fragmentation using an mtu of 1500 with decent latency, I can live with that for now. As I learn more I'll fine tune it and see if I can squeeze a little more out. (it was a process under vista too) The biggest prob is that I don't know what the f^^^ I'm doing yet and a little knowledge can be a dangerous thing in the wrong hands. I am learning though, actually for me fixing what I break is about the best way for me to learn - I don't forget. I've been doing a LOT of reading in the process too. All is well in any case and thank you very much for the replies!

[Kloschüssel]

Just to put the note:

MTU is the maximum bytes to be sent in one packet. Setting it to 1500 would send a packet with max 1500bytes. For large files it decreases the amount of payload significantly, which in turn speeds up the transfer. The MTU is set based on the hardware of the network. 100mbit Ethernet has a MTU of 1500, gigabit ethernet 9000 and so on. But note that commonly a MTU over 1500 is nowadays mostly not supported by mainstream routers (they would need more memory and other things that increase the costs of producing the unit) and can harm flawless network functionality.

Please mark the thread as SOLVED.

[spazdaddy]

Yeah, it's the default for this router and connection - 50Mbs cable(guaranteed minimum speed from comcast.) The biggest issue with it right now is trying to normalize things for both the teenager's netbook and my hard wired connection. Switching to WEP helped quite a lot it seems. 0% fragmentation with an "okay" round trip, I haven't pinged since I switched it but going from 350 - 400KBs to about 1,000-1,200KBs average isn't too bad for now.
Not as fast as it is under windoze but it'll get there(I'd still rather use Linux.) The anomalous behavior was occuring when she logged on which is what gave me the clue. Sometimes you can't see the forest for the trees.
Thanks all!

[Kloschüssel]

Probably Off-topic but WEP can be regarded as insecure just like an open system would be. With enough traffic a WEP key can be cracked within few minutes.

So if you have sensitive data flowing/existing in your network (i.e. you do things like internet banking), consider to use WPA2. Recent hardware should not be hit by performance problems and there should be literally NO difference from the performance point of view.