|  |  | The key to having read/write access to an SNMP-enabled router is the community string. Once the hacker has this string, he can change the configuration of your router. This includes anything from changing an Access Control List and opening holes in it, to adding a static route to direct your traffic to a non-existent network, thus providing a Denial of Service attack on your network. It is recommended that you disable SNMP on your router, or at least limit its access only to internal interfaces.