www.rit.edu possible PMTUD issue?

gistfile1.txt

rtucker@ernestine:~$ ip -6 addr
[...]
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 2001:470:8aed:100::22/64 scope global 
       valid_lft forever preferred_lft forever
[...]

rtucker@ernestine:~$ mtr --report --report-wide www.rit.edu
Start: Thu Feb 25 21:24:41 2016
HOST: ernestine                                     Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 2001:470:8aed:100::                            0.0%    10    0.4   0.4   0.3   0.4   0.0
  2.|-- InterlockRoc-1.tunnel.tserv4.nyc4.ipv6.he.net  0.0%    10   29.9  29.2  27.5  30.5   0.7
  3.|-- ge3-8.core1.nyc4.he.net                        0.0%    10   32.2  29.9  23.7  39.2   5.4
  4.|-- 10ge5-1.core1.nyc6.he.net                      0.0%    10   26.3  28.4  24.4  36.0   3.4
  5.|-- 2001:504:1::a500:4323:1                        0.0%    10   28.2  28.0  25.7  36.9   3.2
  6.|-- 2001:4871:ffff:f000:168:215:52:164             0.0%    10   40.1  40.9  34.6  65.8   9.2
  7.|-- 2001:4870:c1c2:d::2                            0.0%    10   43.3  43.3  35.3  72.1  13.0
  8.|-- rit-core2-pp-rit2-vlan2812.rit.edu             0.0%    10   34.8  39.7  34.8  64.8   9.0
  9.|-- 2620:8d:8000::48                              10.0%    10   37.6  37.5  35.1  39.9   1.3
 10.|-- ???                                           100.0    10    0.0   0.0   0.0   0.0   0.0

rtucker@ernestine:~$ curl -v http://www.rit.edu/
* Hostname was NOT found in DNS cache
*   Trying 2620:8d:8000:0:aba:ca:daba:217...
* Connected to www.rit.edu (2620:8d:8000:0:aba:ca:daba:217) port 80 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.35.0
> Host: www.rit.edu
> Accept: */*
> 
[hangs here for many minutes until I give up]
^C