North American Network Operators Group|
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical
Re: PPPOE, MTU, and boom.
On Wed, 18 Jul 2001, Chris Wedgwood wrote: > On Wed, Jul 18, 2001 at 07:57:23AM +0100, Stephen J. Wilcox wrote: > > Could it be Path MTU/fragmentation issues on account of the low > MTU you have in combination with some ICMP issues where network > admins have some screwy setup? > > That's exactly what it is... a large (1500 byte probably) TCP datagram > with the DF bit set will be heading towards his edge device which are > PPPoE connected. Great domain, btw (f00f.org, brings back memories of division)... Anyway, a great stride was just made in my lab^H^H^Hbasement. First off, it appears a 'ip mtu 1492' on the Virtual-Template of the IOS Router aggregating the PPPOE session is not strictly enforced, especially with windows. Another words, I saw in the PPP debug that the MRU wasn't being negotiated. So, I found this really nifty utility, aptly named 'Mr. TCP': http://www.dslreports.com/front/drtcp.html It allows you to tinker with the Windows settings of TCP. I adjusted MTU to 1400, wham-o, all the sites I listed started working; including, what I didn't list before, the downloading of transactions via Quicken. Seems to be a fixall. -- Alex Rubenstein, AR97, K2AHR, firstname.lastname@example.org, latency, Al Reuben -- -- Net Access Corporation, 800-NET-ME-36, http://www.nac.net --