A BSTRACT  
1 Introduction  
2 Methods and Notation  
2.1 Internet Robustness  
2.2 Layer Models and Graph Models of the Internet  
2.3 Challenges and Aspects of Robustness  
2.4 Metric Selection and Article Structure  
2.5 Features of Metrics  
2.6 List of Symbols  
3 Adjacency  
4 Clustering  
5 Connectivity  
6 Distance  
7 Throughput  
8 Spectral Methods  
9 Geographical Metrics  
10 Comparison and Discussion  
10.1 Backbone Identification and Evaluation  
10.2 Disconnection Robustness  
10.3 Transmission Speed Robustness  
10.4 Traffic Robustness  
10.5 Ambiguity and Correlations of Metrics  
11 Conclusion