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-   -   Bandwidth very slow 28 kbps with EtherAnt II (https://www.linuxquestions.org/questions/linux-networking-3/bandwidth-very-slow-28-kbps-with-etherant-ii-446296/)

QtCoder 05-18-2006 11:59 PM

Bandwidth very slow 28 kbps with EtherAnt II
 
Greetings.

Whenever I get connected to the Internet in Linux (currently Slax 5.1.4) via my dad's EtherAnt II antenna, I consistently get 28 to 30 kbps download speed. In Windows, however, I can get the full 450 to 550 kbps that I should be getting.

This EtherAnt antenna sits on top of the house and connects wirelessly to a tower across town. It connects to my computer via a direct ethernet connection, no drivers needed. The Linux computer I connected it to is a homemade AMD Athlon 1 Ghz with 128 MB ram and SiS PCI900 Fast Ethernet onboard nic. My main goal here is to set up a gateway/firewall for my dad's lan.

I have tried everything I could possibly think of to resolve this, including:

* checking all cables to make sure they are securely connected
* using different cat5 cables
* trying another NIC
* making sure all IP addresses, gateway, dns, etc are correct
* trying another computer with Linux!
* trying several other distros (DSL, ClarkConnect, Smoothwall)
* connecting the EtherAnt to a switch, then to the computer (I thought perhaps the signal was degrading)
* eliminating any sources of interference

All of those actions (and almost every combination of them) produce exactly the same result: 28 to 30 kbps throughput. This is not intermittent. It's constantly 28 to 30.

There is only one thing that has allowed me to attain max throughput: connect the EtherAnt to a Windows XP PC (with two NICS); connect the XP PC to a switch; connect the Linux box to the switch. This "fixes" the problem!! However, it completely destroys my initial plan. Running a Linux PC through a Windows gateway is exactly the opposite of what any sane person would want to do, right? ;)

So, what's the problem here? I've been doing some Googling on this EtherAnt II, but haven't found anything helpful yet. I do not know how to check the configuration (essid, etc) of it either. I suppose more googling is in order.

In the meantime, if anyone has a suggestion, I'd love to hear it! :)

QtCoder 05-24-2006 08:08 PM

Well, apparently no one has any ideas on this.

I've tried running Ethereal (through Knoppix 4.0.2) on the gateway computer to see just what is happening to my packets. I immediately saw a bunch of PPPoE Active Discovery Initiation packets coming in at a rate of ~1/min. No big deal really; they're small packets. My WISP doesn't use PPPoE, nor does the other WISP in town. Clearwire recently came to town, and perhaps they use PPPoE. Regardless, Windows XP receives exactly the same packets and does just fine.

I then figured I'd try Windows 98 on the gateway. However, it behaved exactly like the Linux distros I've tried. If I had an extra copy of XP, I'd try that as well.

A friend suggested two possibilities: 1) A speed mismatch (as in 100baseT NIC vs 10baseT Etherant) or 2) Some difference in the implementation of the TCP/IP stack between Linux and Windows. Using ethtool in Knoppix, I could see that it was correctly using 10baseT/half-duplex. Number 2 just seems very unlikely to me.

So at this point, I'm completely stumped! Again, any suggestion is appreciated.

QtCoder 06-20-2007 01:09 AM

ROFL!

I was looking over my past posts today and came across this one. The problem was simple: the MAC address of the gateway/firewall wasn't registered with the ISP. I had heard at one time that they did authentication by MAC address, but completely forgot about it... although it is a little odd that I was able to connect at all.

Oh well, that's ancient history. No one will probably ever read this anyway!


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