A method of managing a network, comprising: accessing a network topology map for a network comprising a set of probe servers, a set of name servers, and a set of connections between the set of probe servers and the set of name servers; accessing a set of reliability data for the network; generating a network model for the network based on the network topology and the set of reliability data; and identifying, based on the network model, a minimum number of probe servers for use in the set of probe servers required to support a target service level to monitor the set of name servers, wherein the network topology map comprises a set of pyramids, each pyramid having one name server of the set of name servers at a peak and representing connections between at least two probes in the set of probe servers and said name server, wherein the set of reliability data comprises: a predicted failure rate for the set of probe servers, a predicted failure rate for the set of name servers, and a predicted failure rate for the set of connections, wherein generating a network model comprises, based on the set of reliability data: calculating a probability of failure of at least one of the pyramids, wherein an entire pyramid is considered out of service if no more than one probe connected to the subject name server at an apex of the pyramid is in service, and that name server is also out of service; and calculating a probability of having one or more false positives for the whole topology, wherein a false positive corresponds to a false detection of a name server failure and wherein a false positive corresponds to a case when a name server is in service but the network is down along the lines connecting the probe servers and the name server, and wherein identifying, based on the network model, a minimum number of probe servers depends on these probabilities. accessing a network topology map for a network comprising a set of probe servers, a set of name servers, and a set of connections between the set of probe servers and the set of name servers; accessing a set of reliability data for the network; generating a network model for the network based on the network topology and the set of reliability data; and identifying, based on the network model, a minimum number of probe servers for use in the set of probe servers required to support a target service level to monitor the set of name servers, wherein the network topology map comprises a set of pyramids, each pyramid having one name server of the set of name servers at a peak and representing connections between at least two probes in the set of probe servers and said name server, wherein the set of reliability data comprises: a predicted failure rate for the set of probe servers, a predicted failure rate for the set of name servers, and a predicted failure rate for the set of connections, wherein generating a network model comprises, based on the set of reliability data: calculating a probability of failure of at least one of the pyramids, wherein an entire pyramid is considered out of service if no more than one probe connected to the subject name server at an apex of the pyramid is in service, and that name server is also out of service; and calculating a probability of having one or more false positives for the whole topology, wherein a false positive corresponds to a false detection of a name server failure and wherein a false positive corresponds to a case when a name server is in service but the network is down along the lines connecting the probe servers and the name server, and wherein identifying, based on the network model, a minimum number of probe servers depends on these probabilities. a predicted failure rate for the set of probe servers, a predicted failure rate for the set of name servers, and a predicted failure rate for the set of connections, wherein generating a network model comprises, based on the set of reliability data: calculating a probability of failure of at least one of the pyramids, wherein an entire pyramid is considered out of service if no more than one probe connected to the subject name server at an apex of the pyramid is in service, and that name server is also out of service; and calculating a probability of having one or more false positives for the whole topology, wherein a false positive corresponds to a false detection of a name server failure and wherein a false positive corresponds to a case when a name server is in service but the network is down along the lines connecting the probe servers and the name server, and wherein identifying, based on the network model, a minimum number of probe servers depends on these probabilities. calculating a probability of failure of at least one of the pyramids, wherein an entire pyramid is considered out of service if no more than one probe connected to the subject name server at an apex of the pyramid is in service, and that name server is also out of service; and calculating a probability of having one or more false positives for the whole topology, wherein a false positive corresponds to a false detection of a name server failure and wherein a false positive corresponds to a case when a name server is in service but the network is down along the lines connecting the probe servers and the name server, and wherein identifying, based on the network model, a minimum number of probe servers depends on these probabilities.