type: u32
help: Set refresh timer
syntax:expression: $VAR(@) >= 10 && $VAR(@) <= 1800; "must be between 10-1800"
val_help: u32:10-1800; Timer value in seconds

update: vtysh -c "configure terminal" \
          -c "router ospf"                                        \
          -c "no refresh timer" -c "refresh timer $VAR(@)"; 

delete: vtysh -c "configure terminal" \
          -c "router ospf"                                        \
          -c "no refresh timer $VAR(@)";