Effective detection of network anomalies is crucial when it comes to security of computer networks, but traditional methods tend to fail when used to address a wide range of traffic and dynamically changing conditions. This paper provides a systematic review of eight ensemble algorithms, including Random Forest, Extra Trees, Bagging, AdaBoost, Gradient Boosting, HistGradientBoosting, Stacking and Voting, on a dataset of 4,998 samples where 35 features were statistics of network traffic. The data underwent preprocessing based on cleaning, normalization and encoding, and we evaluated the models based on stratified 10-fold cross-validation which used accuracy, precision, recall, F1-score and AUC. Our findings reveal that Stacking with a meta-ensemble produced the best results of 98.90 percent and Voting closely followed with 98.85 percent. Random Forest and Extra Trees also showed strong results of more than 98 percent, whereas the weakest result of 78 percent was obtained in Gradient Boosting, which is sensitive to the configuration of the data. These results offer solid empirical support that ensemble architectures, specifically stacking and voting, offer highly precise, scalable, and practical solutions to state of the art intrusion detection systems.