New Q3 data from Synergy Research Group shows that Cisco’s share of the total worldwide switching and router market was 51%, with shares in the individual segments ranging from 63% for enterprise routers to 38% for service provider routers. This was its best market share performance since the first quarter of 2016. For the last four quarters in aggregate Cisco’s market share was 50%, two percentage points down from the preceding four quarters. Behind Cisco the ranking of vendors was different in each of the three main segments but in aggregate Cisco is followed by Huawei, Juniper, Nokia and HPE. Their overall switching and router market shares were in the 4% to 10% range in Q3. There is then a reasonably long tail of other vendors, with Arista and H3C being the most prominent challengers.