topic Re: Slow internet speed in Operating System - Linux

Slow internet speed

Vernon Brown_4 — Thu, 28 Apr 2005 16:19:55 GMT

I'm running Apache on Fedora core 1 with the server acting as a router with eth1 connected to my LAN and eth0 connected to a dsl modem to the internet. It worked fine when CentruyTel, my ISP, served advertised speed of 750 kbps. Now they serve advertised speed of 3000 kbps. When they changed speed I noticed very sluggish internet access from my LAN.

Speed tests from my LAN only show 16 kbps.

I get close to the 3000 kbps when connected direct from a Windows laptop through the same dsl modem using the same cable that plugs into my server.

Does anyone know of a speed issue with pppoe on Fedora Core 1 ?

Re: Slow internet speed

Steven E. Protter — Thu, 28 Apr 2005 16:59:00 GMT

Its possible its a Fedora Core issue. Have you run yum or up2date and still had the problem?

It could be a problem with the network driver for the lan card you are using or the system is merely overloaded with other work.

I've succesfully used Fedora Core and Red Hat ES for this function and goten maximum throuhput.

Are you using iptables to handle the routing? Its better than ipchains.

SEP

Re: Slow internet speed

Vernon Brown_4 — Thu, 28 Apr 2005 19:03:41 GMT

I'm using IPtables; top shows 85% idle, this while running UpToDate from the icon. I haven't updated since the ISP increased advertised speed to 3.0 mbps. Updating now; I'm hoping.

Re: Slow internet speed

Stuart Browne — Thu, 28 Apr 2005 20:50:07 GMT

Slow throughput can be caused by a number of things. What to look out for:

NIC incompatability. This is pretty rare these days, but what NIC's do you have, and what drivers are you using?

TC and IPTables limiting. using 'iptables -nvL | grep limit' to see if IPTables is doing any throttling (doubtful), and also check the output of the following commands:

tc -s qdisc dev eth0
tc -s class dev eth0
tc -s qdisc dev eth1
tc -s class dev eth1

The 'qdisc' ones should return something simliar to this:

qdisc pfifo_fast 0: [Unknown qdisc, optlen=20]
Sent 32744469947 bytes 58074299 pkts (dropped 0, overlimits 0)

The other two should return nothing. If they do, you've got some QoS stuff happening.

Cabling.. You have the DSL plugged directly into 'eth0' right? The other interface, is that plugged into a Hub or a Switch? or Cross-over directly to the other PC? Make sure there isn't network congestion.

Next... You said you clicked on the 'Up2Date icon'. So you're running X on the Linux box. Are you using it as an active desktop computer, or only as a webserver/router/etc. ? If not a desktop, then shut X down (telinit 3). It saps resources!

Resources.. Use top, see how much memory is in use, how much is as swap. If the kernel code is swapping too much, packet-monkey stuff will be slowed down considerably.

I'm doing pretty much what you're doing. I've got a FC1 box here running Squid, Apache, Sendmail, firewall, packet monkey etc. for my LAN through a DSL, with LAN via a switch on one interface and DSL on the other. I've only got a 1536Kbps (1.5Mbit) pipe, but have no issues such as you're witnessing.

Re: Slow internet speed

Huc_1 — Fri, 29 Apr 2005 06:04:29 GMT

Stuard, maybe a typo error in you reply ? I try your tc command but they did not work as such, I am trying this on Fedora core 3 as I do not have a Fedora core 1

I found that after reading the man page that the following invocation works.

#tc -s qdisc show dev eth0
#tc -s class show dev eth1

Thank for passing on this command, reading the man page open up a whole lot of stuff I did not know about how the kernel works with the network interfaces.

Vermon, maybe this also the right syntax on Fedora core 1 ?

Jean-Pierre Huc

Re: Slow internet speed

Stuart Browne — Fri, 29 Apr 2005 06:33:52 GMT

err, yea, you're right.. I left the 'ls' (or 'list' or 'show') out.

Hrm.. FC3.. *pokes the FC3 box down the street*...

qdisc pfifo_fast 0: bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
Sent 913658944 bytes 2233772 pkts (dropped 0, overlimits 0 requeues 0)

would be what the 'qdisc' would show... slightly different.

Re: Slow internet speed

Florian Heigl (new acc) — Fri, 29 Apr 2005 07:12:49 GMT

You tested from the lan, from a directly connected laptop - please also test from the server itself.

If You don't get the 3Mbit's there, You should try lookup at Your pathmtu and window size settings, maybe something got mixed up.

if that looks okay, then go on searching into the PPPoE issues.

Re: Slow internet speed

Vernon Brown_4 — Fri, 29 Apr 2005 08:05:29 GMT

I shutdown IPtables with
service iptables stop
Shutdown apache, named, and mysql, disconnected the LAN and tested directly from the server, using X only to do the tests. Normally the box in in run level 3.

Top shows 93% idle.

Retest; still very sluggish; shows 16.4 kbps.

I notice the link light on the modem blinks during the test. Normally it is solid green when the cable between the DSL modem and eth0 is plugged in. It didn't blink when it worked at the slower 750 kbps ISP service.

I'm not sure of the eth0 card, it's been about 5 years since I installed it.

Re: Slow internet speed

Stuart Browne — Fri, 29 Apr 2005 09:50:16 GMT

Hrm.. What class of machine are we talking about here? 5 years ago?

Figure out what sort of processor, but more importantly, what type of network card is in there.

Start with 'lsmod' and /proc/{cpuinfo,ioports}

Re: Slow internet speed

Florian Heigl (new acc) — Fri, 29 Apr 2005 10:14:39 GMT

The first guy to tell that a 586 won't be able to handle a DSL line without nat/filtering, I'll shoot.

:))

Re: Slow internet speed

W.C. Epperson — Fri, 29 Apr 2005 10:52:40 GMT

The throughput with the Windows machine says the issue is probably the Ethernet setup between the FC1 box and the modem. If it were a PPPoE issue it would probably show up under Windows as well.

The flashing light is probably indicating collisions, which shouldn't happen on the TP link you're presumably using. This is usually because of an half-duplex/full-duplex mismatch, and that usually results from an autonegotiation failure. Which usually results from only one side being set to autonegotiate, with the other side locked to FD or HD.

"/sbin/ethtool eth0" will show you your interface settings on the Fedora box (if the command was there in FC1). See the man (man ethtool) for manipulation of the settings. There's also the deprecated "mii-tool", which may be present in your version. Good luck.

Re: Slow internet speed

Vernon Brown_4 — Fri, 29 Apr 2005 16:36:21 GMT

I replaced both eth cards with D-Link DFE-5330TX+ cards thinking that W.C. probably nailed it. So I'm saving the bunny until I get back up and running.

I mistakenly checked On Boot, for eth0 so it timed out on boot and DSL didn't start. Now I'm trying to remember the setup.

I think I have pppoe.conf and pap-secrets set up right, ifconfig shows ppp0 with the correct IP. adsl-stop and adsl-start seem to function correctly. adsl-status shows the correct IP.

I can ping the IP from the box itself but not from outside it. Can't get to the internet yet.

Re: Slow internet speed

Vernon Brown_4 — Fri, 29 Apr 2005 17:54:03 GMT

I think I don't have the gateway setup correctly on eth0. When I look at the gateway listed it is the address of the box itself. Is that what it should be ?

Re: Slow internet speed

Vernon Brown_4 — Sat, 30 Apr 2005 07:11:09 GMT

Problem solved; it was the old card that was a 100 not a 10/100. W.C. had it right.

My problem getting back up was that I forgot that 127.0.0.1 would work as the gateway for the DHCP assigned IP.