DPC3941B Firmware Upgrade Broke IPV6

Phone apps and some websites no longer work properly if IPv6 is "half broken" as we seem to be experiencing with Comcast. If IPv6 is detected at all, some apps and websites try their best to stick with IPv6, and Comcast's "half broken" situation just leaves those apps/websites waiting forever, ultimately leaving users with a broken app. Comcast, please dig deep into this and fix it.

My modem was rebooted by comcast again last night, and of course, it broke IPv6 again by giving me a different prefix ... ARRRGGGHHH. .now playing PD roulette until I get the old prefix back.

How do you get a new prefix ("PD roulette")? I seem to be stuck with the same 6ecX prefix (my /56 is 6e00)

@mahdi_c : you need to delete the DUID on your firewall/router. This is the latest iteration of a script I am using for my opnsense firewall:

#!/usr/local/bin/bash
while [ "1" == "1" ] ; do
prefix=$(cat /tmp/em0_pdinfo)
if [ "$prefix" == "<insert your dream prefix here>" ]; then
  echo "all good"
  exit
fi
cat /var/db/dhcp6c_duid | hexdump | grep 0000000
rm /var/db/dhcp6c_duid
if [ ! -f /tmp/em0_pdinfo ]; then
  echo "no prefix file yet"
  exit
fi
pid=$(cat /var/run/dhcp6c.pid)
kill -9 $pid
echo dhcp6c killed
sleep 10
/usr/local/sbin/dhcp6c -c /var/etc/dhcp6c.conf -p /var/run/dhcp6c.pid
tcpdump -i em0 -vc2 -nn port 546
echo dhcp6c restarted
sleep 10
ls -l /tmp/em0_pdinfo
cat /tmp/em0_pdinfo
done

Here is an updated script for opnsense (note there are two spots where you need to insert your desired IPv6 prefix):

#!/bin/csh
set prefix=0
while ( $prefix != '<DESIRED IPv6 PREFIX>' )
  if ( -f /tmp/igb0_pdinfo) then
     set prefix=`cat /tmp/igb0_pdinfo`
     if ( prefix == '<DESIRED IPv6 PREFIX>' ) then
       exit
     endif
  else
     set prefix=0
  endif
  set pid=`cat /var/run/dhcp6c.pid`
  kill -9 $pid
  sleep 5
  rm /var/db/dhcp6c_duid
  rm /tmp/igb0_pdinfo
  /usr/local/sbin/dhcp6c -c /var/etc/dhcp6c.conf -p /var/run/dhcp6c.pid
  while ( ! -f /tmp/igb0_pdinfo )
    sleep 1
  end
  cat /tmp/igb0_pdinfo
end