[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

TCP not working over ppp connection (repost)

Sorry for the repost. I am new to the list and I was just informed by
another user that due to the way I posted my original thread, it got buried
as a reply to another thread... This is my 6th day using linux and 3 of it
have now been spent with this problem - I am about ready to pull my hair

I am Using Debian 2.6 Kernel and the Kyocera KPC650 PCMCIA modem card over
Verizon. I do not know how to better describe my OS, but I downloaded the
180MB install image from debian.org and I type in "debian26" to get my
install working.

I am starting with a fresh load - nothing on there that was not installed by
default. Set it up with ONLY the ppp interface. The goal right now is just
to get TCP working over my ppp0 connection before I do anything else to the

To get my modem to work I had to do the following: (I got these instructions
from other people using this modem in a Linux environment and some that I
figured out by dumb luck) 

modprobe usbserial vendor=0xc88 product=0x17da maxSize=2048 (I have to do
this every time I reboot. I am not sure why, but it is very annoying) 

ln -s /dev/ttyUSB0 /dev/modem (this I think links my USB port to a generic
name "modem" used by dialers) 

nano -w /etc/ppp/options
(I add these because they are not supported by my modem and cause a
disconnect every 2 minutes) 

After all this, I can dial-up using pppd, I get an IP from the ISP, I get
DNS servers from the ISP, the connection seems great, I can ping IPs and
domain names on the Internet - DNS resolution works like a champ, etc. 

The problem is that outbound TCP traffic is being somehow blocked from going
over ppp0. ICMP works just fine. I do not know how to test if inbound TCP
works, but everything that I try that requires TCP, does not work. wget gets
locked up. Aptitude cannot find servers over http or ftp. ez-ipupdate locks
up while trying to reach members.dyndns.org:80 

What would cause this?! Is there some TCP package that I need to install?
Some "enable TCP" command that needs to go into a file somewhere? Please

PS: I know for a fact that this is not a problem with my ISP. Same modem and
account work fine in Windows. Also, before I blew away my Linux box and
started over, I had a web server behind my Linux box connected via Eth0 and
routed the ppp0 connection over to it. I was able to browse from the web
server and pull up the websites on the web server via my ppp0 connection,
all of which requires TCP. At that configuration, my linux box was still
unable to get it's own TCP connection to work via ppp. 

That configuration has now been blown away and all I have is the default
load of Debian running pppd and nothing else. No custom routhing - nothing
that would cause this problem.

Tyson Varosyan
Technical Manager, Uptime Technical Solutions LLC.
206-715-TECH (8324)


Reply to: