Date: Thu, 26 Dec 2002 04:26:24 -0800 (PST) From: Rostislav Krasny <rosti_bsd@yahoo.com> To: freebsd-net@freebsd.org Cc: freebsd-questions@freebsd.org Subject: PPPoE and troubles with TCP Message-ID: <20021226122624.79372.qmail@web14812.mail.yahoo.com>
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Hello I have Alcatel Speedtouch Home ADSL modem. I use PPPoE protocol for connection with my Internet Service Provider (ISP) through this ADSL modem. I use FreeBSD 4.7-RELEASE and ppp (a.k.a. user-ppp) for this. In the /etc/ppp/ppp.conf file I have ' set MRU 1492' and ' set MTU 1492' options. This is because the maximum MTU one can use with PPPoE is 1492 according to RFC 2516. I have no problems with "dialing" to my ISP. But after the PPPoE connection is established I have troubles with TCP connections to some hosts. For example I can't go to hhtp://www.ssh.com/ but to http://www.freebsd.org/ or http://www.gnu.org/ I can. If I run 'telnet www.ssh.com 80' and enter HTTP request according to HTTP 1.1 or 1.0 protocol I don't get any answer. If I enter just 'GET /' I get some short answer. 'GET /' is an HTTP request according to the old HTTP 0.9 version of the protocol and it is rarely used today. But the problem is not HTTP, I think. If I do HTTP request according to HTTP 1.1 from my friends' computer I do have some long answer. Furthermore if I change the MRU and MTU to 1484 or smaller I have no problem with www.ssh.com. So it looks like TCP packet overflow or something like that. Besides FreeBSD I have Windows 98 Second Edition in my computer. I use PPPoE with Win98SE too. I use RASPPPOE driver fo it, go to http://www.raspppoe.com/ for more information. I have no problems with www.ssh.com when I use Win98SE with this impimentation of PPPoE protocol. I have MTU == 1492 set by default in RASPPPOE. I don't get error messages about fragmentation when I run 'ping -f -l 1464 www.ssh.com' in my Win98SE (ICMP+IP=1464+28=1492). Why in FreeBSD I cannot use MTU == 1492 without problems with some hosts like www.ssh.com ? How to fix it in FreeBSD? P.S. ping have different syntax in Windows, so don't be wondered about -f flag. -f sets "no fragmentation" flag in IP headers of all outgoing packets. __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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