nanog mailing list archives
Re: PPPOE, MTU, and boom.
From: Simon Lockhart <simonl () rd bbc co uk>
Date: Wed, 18 Jul 2001 07:53:09 +0100
I have confirmed that when I block all ICMP to/from a website, we cannot browse that site -- which is somewhat obivious. The question is, how, as an internet community as a whole, do we fix this? Seems to me that most people using PPPOE would have a problem here. Or, am I alone? My testing has been limited to Win2k, but I've heard similar reports on WinME, 98, etc.
We've come across this too, and spent quite a while diagnosing. The problem exists wherever there's an MTU reduction, and is caused by a combination of ICMP filtering (breaks PMTUD), and Microsoft's attempt at PMTUD (they just set the DF bit on all packets and expect to get an ICMP reply back if the packet is too large). Simon -- Simon Lockhart | Tel: +44 (0)1737 839676 Internet Engineering Manager | Fax: +44 (0)1737 839516 BBC Internet Services | Email: Simon.Lockhart () bbc co uk Kingswood Warren,Tadworth,Surrey,UK | URL: http://support.bbc.co.uk/
Current thread:
- PPPOE, MTU, and boom. Alex Rubenstein (Jul 17)
- Re: PPPOE, MTU, and boom. Simon Lockhart (Jul 17)
- Re: PPPOE, MTU, and boom. Stephen J. Wilcox (Jul 17)
- <Possible follow-ups>
- Re: PPPOE, MTU, and boom. Alex Rubenstein (Jul 18)
- Re: PPPOE, MTU, and boom. Alex Rubenstein (Jul 18)
- Re: PPPOE, MTU, and boom. Jamie Bowden (Jul 18)
- Re: PPPOE, MTU, and boom. Alex Rubenstein (Jul 18)
- Re: PPPOE, MTU, and boom. Charles Sprickman (Jul 18)
- Re: PPPOE, MTU, and boom. Robert Boyle (Jul 18)
- Re: PPPOE, MTU, and boom. Alex Pilosov (Jul 18)
- Re: PPPOE, MTU, and boom. Jeff Mcadams (Jul 18)
- Re: PPPOE, MTU, and boom. Miquel van Smoorenburg (Jul 18)
- Re: PPPOE, MTU, and boom. Alex Rubenstein (Jul 18)