Hello all,
This is an issue that had me stumped for quiet a while but thankfully i had the help of a CCIE with tons of experience. So i will briefly describe my issue, how we narrowed it down, and so forth.
Prior changes made: switch upgrade for one of our locations from a 3850 to a C9200 with 17.03.05. IP phone 7821 lost its "Park" soft key option a few weeks after the upgrade.
We duplicated every config with a separate phone (same model) at a different location and it maintained the right soft key configuration so something was lost in the transit from that location to the main site. I, a novice, was at a loss. So CCIE traveled with me to location and hooked up wire shark to the switch to find there was no FTP between the phones and the DHCP server.
Solution: In our DHCP server under the scope options of the locations IP phone, add option 150 (Cisco IPT) and reboot phones. after that the correct configurations were restored. This has happed at one other location after an upgrade but we still have yet to find a correlation as to why but if you have a similar issue i hope this post finds you well and if you have anything to add that i said incorrectly feel free to correct me.
But if any one could tell me as to why after an upgrade to the switch my DHCP server needed this, and as to why it took almost a month for the issue to show itself that may be helpful to me and others.
