Twitter has become a virtual meeting and affinity space for teachers that allows the generation of online informal learning communities. Through the analysis of a total of 22,897 tweets that included the #Claustrovirtual distributed between the months of March 2020 and January 2022, we have analyzed the frequency and temporal distribution of publication. Through the Graphext program we have carried out an analysis of social networks, specifying the degree of centrality and betweenness centrality, which has allowed us to know the leadership roles assumed by the most active teachers in the hashtag. Through the analysis carried out, we have identified four roles in social networks: transceivers, transmitters, transcenders and traders. To descriptively analyze why and for what teachers use the #Claustrovirtual, we designed an instrument composed of 8 dimensions that was answered by 81 teachers with a high level of participation in the #Claustrovirtual. Among the results obtained, we found that these teachers use the hashtag in their publications both to locate and turn to teachers with more experience, as well as to raise doubts and questions to the community or ask for support from it.