You can also restrict that IP (using the Restrict IP module) from which the node/add was tried to access. Here is a quote about this module (from the module's project page):

... allows administrators to restrict access to the site to an administrator defined set of IP addresses. Anyone trying to access the site from an IP address not in the list of allowed IP addresses will be redirected to an access denied page with the message "Your address is not in the list of allowed IP addresses". No blocks will be rendered, and no javascript will be added to the page. This will happen for any and all pages these users try to access.

You can also use Restrict IP module to restrict the IP from which the node/add was visited.

Here's an excerpt from module's project page:

... allows administrators to restrict access to the site to an administrator defined set of IP addresses. Anyone trying to access the site from an IP address not in the list of allowed IP addresses will be redirected to an access denied page with the message "Your address is not in the list of allowed IP addresses". No blocks will be rendered, and no javascript will be added to the page. This will happen for any and all pages these users try to access.

You can also restrict that IP http://drupal.org/project/restrict_ip from which the node/add was tried to access.

You can also restrict that IP (using the Restrict IP module) from which the node/add was tried to access. Here is a quote about this module (from the module's project page):

... allows administrators to restrict access to the site to an administrator defined set of IP addresses. Anyone trying to access the site from an IP address not in the list of allowed IP addresses will be redirected to an access denied page with the message "Your address is not in the list of allowed IP addresses". No blocks will be rendered, and no javascript will be added to the page. This will happen for any and all pages these users try to access.