The S55 System | 9• Additional Fan module• Optional modules (if using)• Stacking cables, if stackingFeaturesThe S55 offers the following:• S55 CPU and switch processor• Up to 8 stacked units• Stackable switch features• 19-inch rack-mountable• Standard 1U chassis height• Hot Swappable optional modules, power supplies, and fan modules• Up to 16K MAC address entries supported with hardware assisted aging• Supports 9K jumbo framesPorts• Optional ports supporting two 2-port 10G SFP+ modules, or two 2-port 12G stacking module stackingmodules• 44 fixed 10/100/1000 Mbps auto-sensing and auto MDIX RJ45 ports• Four fixed ports supporting 100/1000 Base-T or 1000 Base-X using auto-media detection• Console port (for system access)• USB-A port (for storage)• USB-B port (for system connectivity and access)System statusS55 status information is viewed in several ways, including physical displays and boot menu options.Status information is also seen through the CLI show commands and with SNMP traps. For details onthose options, see the FTOS Command Reference for the S55 and the FTOS Configuration Guide for theS55.LED displaysAs shown in Figure 2-2, the S55 I/O panel contains several sets of LEDs. The Stacking ID LEDs is in theupper half of the chassis, next to the USB-B port. The system LEDs are located to the right of the StackID LEDs.• The Stack ID itself is in decimal format (Figure ).