After having a laptop assigned to a new subnet, a user is no longer able to login to the SSH

server with an error message like Connection closed by remote host. Which of the following
are possible approaches to determine and fix the cause of this problem? (Choose TWO
correct answers.)

A.
Check that there are no netfilter rules that reject SSH connections from the new IP
address.

B.
Add the new IP address of the client to the AllowHosts configuration setting on the SSH
server.

C.
Flush the ARP table and the neighbor discovery cache on both the SSH server and the
client.

D.
Generate a new host key on the client and replace the current client host key on the SSH
server.

E.
Verify that the settings in /etc/host.allow and /etc/host.deny are not preventing access.