Solved
Forum Discussion
Andy_McGrath
Nov 13, 2017Cumulonimbus
You trying to add this on the GUI or TMSH?
If the GUI and the Partition Default Route Domain is set to 3 then you will not need to add the %3 when adding routes.
Also under TMOS 12.x you can use default as the destination for a default route instead of 0.0.0.0/0, try the following on under TMSH:
create net route default_rd3 network default%3 gw 10.0.21.1%3
If that doesn't work might need to share your LTM's net config.