I'm once again considering trying to improve on the <a href="http://test-ipv6.com">test-ipv6.com</a> PMTUD failure detection. Due to limitations on the client side I can't use raw sockets to generate test packets. The client is JavaScript and runs in a browser; all I can do is try fetching urls from multiple locations, each with a different MTU. <div>
<br></div><div>I know that the various operating systems tend to cache any PMTUD issues that they can detect; future connections to that destination will use smaller packets accordingly. What I can not see to find is an adequate description of what granularity this gets cached with. /128? /64? Also, I the absence of Packet Too Big messages, what does each OS do?</div>
<div><br></div><div>If anyone has pointers, please share. It will affect what and how I can improve the site, given the restrictions I have with the client side.</div><div><br></div><br><br><br>-- <br><div dir="ltr"><div>
Jason Fesler, email/jabber <<a href="mailto:jfesler@gigo.com" target="_blank">jfesler@gigo.com</a>> resume: <a href="http://jfesler.com" target="_blank">http://jfesler.com</a></div><div> "Give a man fire, and he'll be warm for a day;</div>
<div> set a man on fire, and he'll be warm for the rest of his life."</div><div><br></div></div><br>