Local net

lackluster · 09-10-2005, 09:42 AM

Peeps -

Here's the deal: On my local network I have a file/web/ftp/etc server, and some wireless goons. On the server it's wired into the router, and gets pretty good (~450Kbps) download and so-so (~65Kbps) upload. The goons, however, have a different story to tell. When downloading files from the server locally, th5ey get crappy rates (~35Kpbs). But when they upload they get acceptable rates (~500Kpbs (802.11(a))).

To illustrate the point:

Server:
===========================
Download (from internet): ~450
Upload (across internet): ~65

Goons (linux, osx):
===========================
Download (from internet): ~400
Upload (across internet): unknown/who cares

Download (from server): ~35
Upload (to server): ~500

Anyone know how to get the download from server on internal network rate up? Please treat me as a networking layman, 'cause I don't know much about it :-/.

Thanks!

Half_Elf · 09-10-2005, 12:49 PM

It would be easier if you could draw some ASCII schema of your network, I'm a bit loss there, what is connected to what?

Sometime, slowdown is due to fragmentation, caused by a too high MTU. My first guess would be to reduce the MTU a bit to see if it does any good. The command is like "ifconfig eth0 mtu 1444". The higher is the better, but if you pass throught a router, it could create fragmentation, which is always bad.

Still, on a local network, "450KB/sec" is sluggish... are you on the net at some point in there? A lot of ISP will give you a very good download speed, but will limit the upload (mine give me 385KB down, but only 85KB down).

lackluster · 09-10-2005, 02:06 PM

I'm glad you want me to draw an ascii schema. I love ascii tables, schemas, and diagrams

Code:

[ ========= ]
[  internet ] ---------- { linksys router }
[ ========= ]                     |                             [ ====================== ]
                                  | <-- ethernet cable          [      wireless B        ]
                                  |                             [ ====================== ]
                 [ ============================= ]
                 [          file   server        ]               [ ==================== ]
                 [ ============================= ]               [     wireless A       ]
                                                                 [ ==================== ]

Pretty standard setup, really.

I get moderate speeds on my local network because I'm accessing over 802.11(a) (least that's why I thought so).

I'll try the mtu thing, thanks for the help thus far.

lackluster · 09-10-2005, 02:25 PM

The mtu thing didn't seem to have any effect.

Half_Elf · 09-10-2005, 02:38 PM

It's a bit weird that only download is slowed down... have you changed the MTU on clients or on server as well? It might be a good guess to try this on the server network card as well...
The problem is probably on the server or (worst case) on the router... I would suggest the usual tricks, like listenning to the network connection using tcpdump or taking a look in logfiles (dmesg and such), maybe it could give you some hints... :/

lackluster · 09-10-2005, 02:48 PM

I think my problems may be larger. I logged into the router and looked at the 'DHCP Clients Table'. It had an unknown computer listed as 10.1.1.104 over ethernet. The only possibility I see is that there's somebody in my basement using all my bandwidth. When I deleted that name from the table, I got my usual speeds back. Does this sound like the work of a 'hacker'? (there is nobody in the basement)

Half_Elf · 09-10-2005, 04:16 PM

Well if you haven't secured your wireless, it's (sorry to be rude) your damn fault. It's less a hacker than just a bright teenager. It's very very important to secure a wireless network, at the very least with WEP key (WEP key are bad, could be craked in 15mins but it will keep most teens away... WPA is quite better). You have no idea how far your network can go,it may not even be in your basement but 3 streeet away, it is always very hard to predict.

Snowbat · 09-10-2005, 04:29 PM

I have a schematically identical setup and my goons (using 802.11b) can pull 650 kilobytes/sec off the file server.

lackluster · 09-10-2005, 04:34 PM

Yeah, I'm aware of the implications. I don't mind a surfer on the network, but a snooper or malicious kid is another thing. I'm actually pretty confused now because my rates have dropped again, and I seem to be the only one on the network. Maybe I'll try yelling at it.