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Phydoux
n00b
Joined: 22 Nov 2003
Posts: 5
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 Posted: Wed Jan 28, 2004 9:40 pm Post subject: FTP transfers limited to ~50 KB/s, what's wrong?? |
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Hello, I was hoping a networking guru could help me with an issue I'm having with my Gentoo Linux firewall.
I've got an IIS server providing FTP services behind a Gentoo Linux box providing NAT and firewall services. The IIS server is using a 192.168.3.3 IP address, and the Linux box has a routable IP address, i.e. it is NATing the FTP server.
I used fwbuilder to build the firewall rules. As far as I can tell from the resulting script, there is nothing in it that appears to be setting limits or throttles on the FTP traffic.
If I log in to the FTP server from the firewall and download a file, it comes down to me at ~6 megabytes per second. That seems to indicate the IIS will send the data as fast as possible.
If I log in to the FTP server from a host on the Internet and download the same file, the transfer is throttled at ~50 KB/s. The connection is on a DSL line and can theoretically transfer ~ 128 KB/s +. I have also connected and copied a file from the firewall via scp and it has copied down at the much faster (and expected) ~128 KB/s.
I have not done anything to deliberately try to throttle the FTP bandwidth and I would like it to transfer the data at the full speed allowed by the connection. I can't figure out what is wrong. Does anybody have any ideas of where I can begin looking or settings that I should check to try and fix this? I'm starting to wonder if mod_conntrack_ftp is introducing overhead or a throttle of some sort.
Any help would be appreciated. |
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fleed
l33t
Joined: 28 Aug 2002
Posts: 756
Location: London
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| Posted: Thu Jan 29, 2004 11:35 am Post subject: |
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Do you have wondershaper running, maybe? What's the CPU usage of the gentoo box when you're transferring? Anything in dmesg about dropped packets?
I think conntrack_ftp is for outgoing connections, am I right? I could be mistaken, obviously.
Also, is it KB or Kb per sec? (could certainly be 1024KB but sounds like a lot for a dsl connection, I only get 256KB). |
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Phydoux
n00b
Joined: 22 Nov 2003
Posts: 5
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| Posted: Tue Feb 03, 2004 6:28 pm Post subject: |
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| fleed wrote: | Do you have wondershaper running, maybe? What's the CPU usage of the gentoo box when you're transferring? Anything in dmesg about dropped packets?
I think conntrack_ftp is for outgoing connections, am I right? I could be mistaken, obviously.
Also, is it KB or Kb per sec? (could certainly be 1024KB but sounds like a lot for a dsl connection, I only get 256KB). |
Hi, thanks for the reply. Sorry it took me so long to respond.
I don't even know what wondershaper is. I certainly haven't gone out of my way to install it. It isn't possible that it was installed as a dependency of another package, is it? What is the package name in portage? Is it even in portage?
CPU usage is at 100% due to ntop running in the background. I started a transfer and let it run for a few minutes, and it shows the load average at 1.25, 1.07, 1.02. No messages regarding dropped packets. I could stop ntop but I am pretty sure that I had this problem even without ntop running.
The server is a P3 1 GHz, which should be more than adequate to handle a 1.2 Gbps DSL line. Oh, yeah, you asked about that. The DSL line is for the company I work for. It is rated at ~ 1.2 Gbps (according to ntop we sometimes peak at ~ 1.4 Gbps usage.) Much cheaper than a T1.
So what is confusing to me is that the FTP transfer ought to allow me to use the full ~ 1.2 Gbps (i.e. approximately 128 KB per second), for some reason it hovers at about 50 KB per second. A little less than half of the full bandwidth available. |
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triwebb1
Tux's lil' helper
Joined: 19 Oct 2003
Posts: 87
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| Posted: Tue Feb 03, 2004 10:31 pm Post subject: |
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| You mean 1.2 Mbps, right? DSL doesn't go anywhere near 1.2 Gbps, as far as I know. What is your upload rated at? You can only download from the firewall as fast as it can upload, so that may be your bottleneck. |
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Phydoux
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Joined: 22 Nov 2003
Posts: 5
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| Posted: Wed Feb 04, 2004 12:15 am Post subject: |
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| triwebb1 wrote: | | You mean 1.2 Mbps, right? DSL doesn't go anywhere near 1.2 Gbps, as far as I know. What is your upload rated at? You can only download from the firewall as fast as it can upload, so that may be your bottleneck. |
Sorry, yes that was a typo on my part. I did mean 1.2 Mbps, and that is supposed to be for both up and down. ntop has shown this to be the case.
A co-worker and I have also tested from our homes. We both have 640 Kbps DSL connections. When either of us start a download, the download rate always settles down to about 50 KB per second. We should be able to get about 65 KB per second with our DSL lines. We both easily get that from other places on the Internet.
If we both start our downloads at the same time from the FTP server at work, we both still get about 50 KB per second, so there is plenty of bandwidth available for the server to handle both of our connections. For some reason, the download rate is always capped at that speed. We have had customers report the same thing to us, so we know we aren't the only ones with the problem. |
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Cr0t
l33t
Joined: 27 Apr 2002
Posts: 945
Location: USA
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| Posted: Wed Mar 09, 2005 1:05 am Post subject: |
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| Phydoux wrote: | | triwebb1 wrote: | | You mean 1.2 Mbps, right? DSL doesn't go anywhere near 1.2 Gbps, as far as I know. What is your upload rated at? You can only download from the firewall as fast as it can upload, so that may be your bottleneck. |
Sorry, yes that was a typo on my part. I did mean 1.2 Mbps, and that is supposed to be for both up and down. ntop has shown this to be the case.
A co-worker and I have also tested from our homes. We both have 640 Kbps DSL connections. When either of us start a download, the download rate always settles down to about 50 KB per second. We should be able to get about 65 KB per second with our DSL lines. We both easily get that from other places on the Internet.
If we both start our downloads at the same time from the FTP server at work, we both still get about 50 KB per second, so there is plenty of bandwidth available for the server to handle both of our connections. For some reason, the download rate is always capped at that speed. We have had customers report the same thing to us, so we know we aren't the only ones with the problem. |
If it's ADSL then it makes sense, but if you have SDSL then it shouldn't happen!
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cya |
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KayJay
n00b
Joined: 13 May 2005
Posts: 2
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| Posted: Fri May 13, 2005 7:59 am Post subject: |
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Sorry, I can't help you with your problem as I'm experiencing a similar problem. In recent months I have installed Gentoo twice. One with a 2.4 Kernal and the latest with 2.6. Both boxes have the same problem, in that the NATed network would experience roughly 50% bandwidth throttling. I can connect to various FTP and HTTP download sites directly from the server and download at 360K/s (Cable 3mbps), yet any PC connected to the server can only download at 180K/s. I have followed several guides for setting up a home router. I have used Shorewall and used iptables manually. Nothing seems to work.
Can anyone help? |
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