Hi all. I tried looking around, but was not able to locate any other posts that quite match what my problem is. If i missed something, please put a link here for me?


Heres the skinny:

redhat 9 running kernel 2.6.2
bellsouth dsl connecting through a westell modem (ethernet).

for some strange reason, i cannot connect to some websites. not all, just some.
a good example is www.mwave.com, or www.eluniversal.com, or www.universalcard.com.

at any rate, i am getting a bit frustrated here.

i have a small 4 port switch connected to the dsl modem for this box and my laptop. my laptop is rh9 with the vanilla 2.4.20-8 kernel. the laptop can connect to these sites with no problem. but i cannot get to them on this machine.

i remember reading somewhere about issues with MTU or RWIN values or something. anyone with any pointers for a direction to fix my problem?

appreciate any help at all!

I could not find the first two sites, DNS error I believe, and the 3rd one only loaded partially with errors.

Those sites look problematic to begin with.

well, the headscratcher is that my winxp box has no problems finding the sites at all. the first two are just a computer parts supplier and a venezuelan newspaper, but the last site is citibank!

drivin me NUTS that i cannot get to those sites. and why in the world would my xp box be able to reach em...

Another thing you can try on linux box is to try telnetting to port 80 then issue HTTP commands


telnet <website address> 80
GET /index.html

This is just for testing to see if website is responding.

i've posted the same problem here (though, i'm not the thread starter):

http://www.linuxquestions.org/questi...hreadid=154465


i cannot connect to those three sites either. i'm also in the southern US and use a 2.6 kernel. i have a winxp box on the same network that connects to these sites just fine. bizarre, isn't it?

when i try to connect to mwave, for example, i get a "connection refused" which is different from being "timed out"

i hope someone can help us, this is driving me right outside my mind : {

i found the problem. it is with Explicit Congestion Notification (ECN). if you are having these problems check whether ecn is on. to do this, on the command line type:

cat /proc/sys/net/ipv4/tcp_ecn

if this returns "1" then ecn is on. to turn it off type:

echo 0 > /proc/sys/net/ipv4/tcp_ecn

now try and go to www.mwave.com

let me know if this works for you

OMG, quantum! You are my new official lovemonkey god! That hit it perfectly. Cheers to you man. out of curiousity, how did you manage to figure that one out?

I cant thank you enough for that little nugget!

What is this...
Explicit Congestion Notification (ECN). ?

Why would someone want it on?

unfortunately, i cannot take the credit. i googled "mwave.com" and "connection refused" and got a debian forum thread:

http://lists.debian.org/debian-user/.../msg04129.html

it describes the same problem. the sites that we couldn't connect to must be running ecn-enabled servers. what i don't understand is why the 2.6 kernel has this enabled by default, with seemingly no way to turn it off through a gui. i think i'll submit a bug report to fedora requesting this.

i'm just glad to be rid of the problem, and even more so since it helped someone else.

i found this informative page:

http://lis1.ph-freiburg.de/~peter/ecn.html

and, here is the ecn home page:

http://www.icir.org/floyd/ecn.html

I am having very similar issues with my new installation of suSE 9.0 on my laptop. after the networking is configured, i can connect to and receive my e-mail, guessing port 110, fairly new. i also have an applet running in gnome that tells me my current weather forcast. both the e-mail and the weather applet work without a hitch. however when i try to connect to a web page, it just times out. now when i had fedora, mandrake, and lindows on the same machine, all connections worked without a hitch.

another intersting thing is, that i use vmware, to run windows 200 pro, and it connects to the internet and the email, through a virtual machine on the same box that can't do it by itself. i dual boot my laptop with windows xp pro, and of course it has no issues at all, but i would like to get rid of windows all together.

any help for me, i am going to try this ecn thing, i'll edit sysconfig with yast to disable it, but i am stumped.

i just installed fedora in a virtual machine with vmware, and it connects to the internet through the virtual connection as well. maybe suse doesn't allow port 80 to be accessed. prot 110 works great, my email downloads no problem, but no web sites.

help me please

seth

sjerome,

did you have a chance to try the ecn fix? if so, did it work out for you?

tried the first 2 sites, loading failed...citibank site came up though...strange though....when i executed the ecn line...it came up 0...didn't have to turn it off....but when i tried mwave again it came up...I'm using 2.4.22 within Mandrake 9.2...

the question(s)...did executing the line initialize something?...i'm still a newbie 2 months into Linux..O'reilly say's "cat" is useful sending files into the shell pipeline...is what what happened?

also wondering if i'll have to repeat the line after powerdown? guess i'll find that out later...don't want to powerdown right now to test....

Thanks in advance
Tom

Was anyone who got a zero return for ECN able to figure this out. I have the exact same problem. Fedora Core 2 final.