Hostname of C3850 changed to a weird IP address after IOS upgrade

[ab_ahmadi]

I tried to upgrade my C3850 stack to the latest IOS-XE (16.6.6) and everything goes fine without any error.but after rebooting the stack , the hostname of the switches change to a weird ip address (188.92.184.163) !!! i am 100% sure that i didn't change the hostname accidentally by no mean . the hostname on the config file also changed so that is not only about running-config. that ip address was not even in my stack configuration and i double checked my terminal that i execute the upgrade command and everything was normal . any clue ???

that is my terminal log :

SUCCESS: Software provisioned. New software will load on reboot.
[1]: Finished install successful on switch 1
[2]: install package(s) on switch 2
--- Starting list of software package changes ---
Old files list:
Removed cat3k_caa-guestshell.16.03.07.SPA.pkg
Removed cat3k_caa-rpbase.16.03.07.SPA.pkg
Removed cat3k_caa-rpcore.16.03.07.SPA.pkg
Removed cat3k_caa-srdriver.16.03.07.SPA.pkg
Removed cat3k_caa-wcm.16.03.07.SPA.pkg
Removed cat3k_caa-webui.16.03.07.SPA.pkg
New files list:
Added cat3k_caa-guestshell.16.06.06.SPA.pkg
Added cat3k_caa-rpbase.16.06.06.SPA.pkg
Added cat3k_caa-rpcore.16.06.06.SPA.pkg
Added cat3k_caa-srdriver.16.06.06.SPA.pkg
Added cat3k_caa-webui.16.06.06.SPA.pkg
Finished list of software package changes
SUCCESS: Software provisioned. New software will load on reboot.
[2]: Finished install successful on switch 2
Checking status of install on [1 2]
[1 2]: Finished install in switch 1 2
SUCCESS: Finished install: Success on [1 2]
EDGE#reload
Reload command is being issued on Active unit, this will reload the whole stack
Proceed with reload? [confirm]Connection closing...Socket close.

Connection closed by foreign host.

Disconnected from remote host(EDGE) at 14:50:29.

Connecting to 1xxxxxx:22...
Connection established.
To escape to local shell, press 'Ctrl+Alt+]'.

188.92.184.163>
188.92.184.163>

188.92.184.163#sh run | i 188.92.
hostname 188.92.184.163

[Reza Sharifi]

Is DNS enabled on the switch?

It appears that the switch was looking for hostname "EDGE" and since it could not find it, it changed it to an IP.

HTH 

[Georg Pauwen]

Hello,

on a side note, the range 188.92.184.0/24 is reserved to internal infrastructure of Milano Teleport SRL in Italy. Is there any relation between your company and Milano Teleport ?

[ab_ahmadi]

Hello guy.the mystery solved .we used object-group in our ACL (for PBR path optimization) to better manage the IP addresses that need special routing via BPR. the mentioned IP address was part of a large object-group and it look like the 16.6.6 don't support object-group !!! the command object-group is missing (no CLI command exist on 16.6.6) and for that reason when we upgrade from 16.3.7 to 16.6.6 all object-group flushed from the config and then some magic happened (thanks  cisco development teams) and put that IP address as hostname of switches !!!.

i am rolling back to 16.3.7 and add the missing object-group from backup file.

thank you guy and thank Cisco for removing object-group from 16.6.6 .