Hi Paul,<br><br><div class="gmail_quote">On Tue, Dec 2, 2008 at 10:10, Paul Black <span dir="ltr"><<a href="mailto:paul%2Bfedora@saturnine.org.uk">paul+fedora@saturnine.org.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div class="Ih2E3d">2008/12/2 Andre Costa wrote:<span dir="ltr"></span><br></div><div class="gmail_quote"><div class="Ih2E3d"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Actually, is this a problem at all or can I safely ignore this?<br>
</blockquote></div><div><br>As Wireshark suggested, this is happens the NIC calculates the checksums for the packet. Since the HW is doing this, the SW doesn't bother, hence the wrong value that appears to be in the outgoing packet. You would need to verify at the receiving end whether there was an actual problem but this is unlikely to be the case.<br>
</div></div><br></blockquote></div><br>Thks, so it's probably nothing to worry about.<br><br>I digged even further and found out that Google-related queries (GMail, GReader etc.) are returning very short TTL values, as can be seen by the wireshark capture snippet below:<br>
<br> Answers<br> <a href="http://www.google.com">www.google.com</a>: type CNAME, class IN, cname <a href="http://www.l.google.com">www.l.google.com</a><br> Name: <a href="http://www.google.com">www.google.com</a><br>
Type: CNAME (Canonical name for an alias)<br> Class: IN (0x0001)<br> Time to live: 10 hours, 31 minutes, 12 seconds<br> Data length: 18<br> Primary name: <a href="http://www.l.google.com">www.l.google.com</a><br>
<a href="http://www.l.google.com">www.l.google.com</a>: type A, class IN, addr <a href="http://74.125.77.99">74.125.77.99</a><br> Name: <a href="http://www.l.google.com">www.l.google.com</a><br> Type: A (Host address)<br>
Class: IN (0x0001)<br> Time to live: 1 minute, 50 seconds<br> Data length: 4<br> Addr: <a href="http://74.125.77.99">74.125.77.99</a><br> <a href="http://www.l.google.com">www.l.google.com</a>: type A, class IN, addr <a href="http://74.125.77.147">74.125.77.147</a><br>
Name: <a href="http://www.l.google.com">www.l.google.com</a><br> Type: A (Host address)<br> Class: IN (0x0001)<br> Time to live: 1 minute, 50 seconds<br> Data length: 4<br>
Addr: <a href="http://74.125.77.147">74.125.77.147</a><br>[...]<br><br>(first one is <a href="http://www.google.com">www.google.com</a>, which has a TTL of 1 day)<br><br>I bet this is why no local DNS cache can help with Google addresses since they expire so quickly. Weird thing is that, on this short monitoring I did (a couple of minutes only), none of the Google sites (aside from the main sites such as <a href="http://www.google.com">www.google.com</a> and <a href="http://mail.google.com">mail.google.com</a>) had a TTL > 5min. Has this always been this way?<br>
<br>Regards,<br><br>Andre<br>