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<div>Hi Tore,</div>
<div> </div>
<div>>Does anyone know what tricks, if any, the major 6RD deployments (AT&T,</div>
<div>>Free, Swisscom, others?) are using to alleviate any problems stemming</div>
<div>>from the reduced IPv6 MTU? Some possibilities that come to mind are:</div>
<div> </div>
<div>>* Having the 6RD CPE lower the TCP MSS value of SYN packets as they</div>
<div>>enter/exit the tunnel device</div>
<div>>* Having the 6RD BR lower the TCP MSS value in the same way as above</div>
<div>>* Having the 6RD CPE advertise a lowered MTU to the LAN in RA Options</div>
<div>>* Several (or all) of the above in combination</div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"> </span></font></div>
<div>We advertise an MTU of 1472 in the RA Options. We still have a small<br>
number of PPPoE users and the max-payload-tag is not working reliably</div>
<div>enough on third-party devices. <br>
<br>
Hence: 1500 Bytes – 20 Bytes IPv4 – 8 Bytes PPPoE = 1472 Bytes</div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"> </span></font></div>
<div>\Martin</div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"> </span></font></div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"> </span></font></div>
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