Hi Rene!
You mention that passive-interface command is preventing an interface from sending hello packets.
I’d like to know technically does it prevent interface from RECEIVING hello packets as well?
Also, I read in an official Cisco literature that it is recommended ISP facing interfaces to be passive for security.
However I don’t understand, if this is the case how is my router going to receive routing to external destinations using OSPF if it doesn’t become neighbor
with the next hop.
Thank you in advance!