I have an ASA 5505 with the boot error 15 no file found.
I have tried with the following commands in ROMMON
address 10.1.1.2
server 10.1.1.1
interface ethernet0/0
file asa924-k8.bin
"the ping between asa and server is good"
tftpdnld
The download times out after 20 sec
What to do?