Extreme 7520 switches can stack with themselves and with Extreme 7720 switches. The Extreme 7520 supports data rates of 100Gbps using the Native V400 stacking method (SummitStack-V400) with QSFP28 cables, or Native-V400-Alternative-configuration with the long range AOC optics. The stacking ports on 7520-48XT-6C models are ports 53 and 54. The stacking ports on 7520-48Y-8C models are ports 55 and 56.