updated zd1200 to fw 9.13.3.0.157 , r600 ap's at local site updated ok but remotes sites fail

[Anonymous]

WE have two zd1200's and 5 sites, the main site has the Zd's and 25 r600 aps, all connected by vpn and each of 5 remote sites has 5 r600 aps
Have successfully updated two ZD and 25 AP's to 9.13.3.0.157 and is working ok, the remote sites have 5 r600's each but these just continually show in zone director with message
Ap {****} joins with different firmware / custom file version and is being upgraded.
These doesnt complete and they can not connnct

[Anonymous]

have you check to see if the r600 is compatible with 9.13.3.0.157?  What model are the APs that successfully upgraded

[Anonymous]

Need to update remote APs, upload image manually

[david_black_594]

Generally the cause for this symptom is an MTU mismatch. Change the ZD’s to a lower number such as 1200 and that should take care of it.