Как вставить строки в комментарии в heredoc?

Это не работает, комментарий не содержит строку IP_ADDR

SSH_UN='user'
IP_ADDR='192.168.1.101'

cat <<"EOF" >> .ssh/config
# VirtualBox (VB) on user's laptop at $IP_ADDR
Host laptopvb
  Hostname $IP_ADDR
  User $SSH_UN
  ForwardAgent yes
EOF

ssh heredoc

Удалите двойные кавычки вокруг EOF:

IP_ADDR='192.168.1.101'
cat <<EOF >> .ssh/config
# VirtualBox (VB) on hobs laptop at $IP_ADDR
Host laptopvb # manually set as a static IP on the VB
  Hostname $IP_ADDR
  User $SSH_UN
  ForwardAgent yes
EOF

Согласно руководство по bash:

The format of here-documents is:

       <<[-]word
               here-document
       delimiter

No parameter expansion, command substitution, arithmetic expansion, 
or pathname expansion is performed on word. If any characters in word are quoted, 
the delimiter is the result of quote removal on word, and the lines in the
here-document are not expanded. If word is unquoted, all lines of the
here-document are subjected to parameter expansion, command substitution,
and arithmetic expansion.