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<div class="moz-cite-prefix">On 10/01/2014 02:37 PM, Chuck Anderson
wrote:<br>
</div>
<blockquote class=" cite"
id="mid_20141001143734_GD16762_angus_ind_WPI_EDU"
cite="mid:20141001143734.GD16762@angus.ind.WPI.EDU" type="cite">
But the LAN interface of that router has an MTU of 1500, as does
my
desktop system. I believe the issue is that the juniper.net web
server has an MTU of 1500 and their network or somewhere along the
path is blocking ICMP Packet Too Big messages that would be sent
by
the HE.net tunnel router.<br>
</blockquote>
<br>
Perhaps, though IMO unlikely.<br>
<br>
I too have a LAN MTU of 1500, and have a (HE.net) tunnel MTU of
1480. I do not see any PMTU problems to <a class="moz-txt-link-abbreviated" href="http://www.juniper.net">www.juniper.net</a> or
elsewhere.<br>
<br>
However, I <i>am</i> explicitly advertising MTU 1480 in LAN RAs.<br>
<br>
Here is a partial outbound route from my origin:<br>
<pre>gapinski@eins:~$ traceroute -6 -A <a class="moz-txt-link-abbreviated" href="http://www.juniper.net">www.juniper.net</a>
traceroute to <a class="moz-txt-link-abbreviated" href="http://www.juniper.net">www.juniper.net</a> (2600:1408:17:293::720), 30 hops max, 80 byte packets
…
3 ge3-4.core1.chi1.he.net (2001:470:0:6e::1) [AS6939] 43.778 ms 43.892 ms 43.876 ms
4 twcable-backbone-as7843.10gigabitethernet1-1-6.switch3.chi1.he.net (2001:470:0:2bb::2) [AS6939] 55.905 ms 55.988 ms 55.983 ms
5 2001:1998:0:4::171 (2001:1998:0:4::171) [AS7843] 39.962 ms 2001:1998:0:4::ed (2001:1998:0:4::ed) [AS7843] 40.635 ms 2001:1998:0:4::171 (2001:1998:0:4::171) [AS7843] 42.125 ms
6 2001:1998:0:4::a3 (2001:1998:0:4::a3) [AS7843] 63.789 ms 49.818 ms 2001:1998:0:4::b1 (2001:1998:0:4::b1) [AS7843] 50.215 ms
7 2001:1998:0:4::80 (2001:1998:0:4::80) [AS7843] 54.505 ms 2001:1998:0:4::a4 (2001:1998:0:4::a4) [AS7843] 55.892 ms 2001:1998:0:4::80 (2001:1998:0:4::80) [AS7843] 55.006 ms
8 2001:1998:0:4::5c (2001:1998:0:4::5c) [AS7843] 57.100 ms 57.060 ms 58.693 ms
9 2001:1998:0:4::90 (2001:1998:0:4::90) [AS7843] 56.811 ms 57.152 ms 2001:1998:0:4::86 (2001:1998:0:4::86) [AS7843] 57.956 ms
10 2001:1998:0:4::f4 (2001:1998:0:4::f4) [AS7843] 55.055 ms 2001:1998:0:4::1a1 (2001:1998:0:4::1a1) [AS7843] 55.153 ms 2001:1998:0:4::f4 (2001:1998:0:4::f4) [AS7843] 55.107 ms
11 2001:1998:0:8::2c6 (2001:1998:0:8::2c6) [AS7843] 56.198 ms 56.771 ms 55.622 ms
12 2600:1408:17::17dc:947c (2600:1408:17::17dc:947c) [AS20940] 49.388 ms 59.963 ms 60.354 ms
gapinski@eins:~$
</pre>
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