Cisco SG300-10MPP

Cisco · managed switch, 10 ports, 8 with PoE · Cisco SG300-10MPP

what it is

A managed switch in a chassis 279.4 mm wide, i.e. narrower than a nineteen-inch rack. Eight gigabit ports deliver PoE (power over the cable) in the PoE+ standard, from a shared 124 W budget, up to 30 W per port. Two more are combo ports — copper or a fiber transceiver (SFP module), one or the other, not both at once. Passive cooling, no fan.

The power supply is external. At the back there is no mains power socket, only a low-voltage socket — and the power supply itself has to be put somewhere. When planning a rack, that space is easy to overlook, because the datasheet mentions it in a single word.

The height is 44.45 mm, i.e. one rack unit. The datasheet for this series gives 1.45 inches next to it, which is not the same number; the datasheet of the successor in the same chassis is consistent and gives 44 mm.

Lifecycle: vendor support for the Small Business 300 series ended on August 31, 2023. The last firmware for this family was released in June 2020 — there will be no newer one.

what we read from it

Over SNMP: the state of every port with speed and duplex, transmitted and received traffic on 64-bit counters, error counters, system name, firmware version and serial number. In addition:

• PoE on every port separately: voltage, current, actual draw, allocated limit and a status description in words. Actual draw is a different number from the allocation: an access point with a 30 W limit draws about 12 W.
• The budget of the whole switch — available power, current consumption and the device's own alarm threshold (95%).
• CPU load over the last second, minute and five minutes.
• Neighbors via CDP and LLDP. CDP sees only Cisco equipment — but with its firmware version; LLDP also sees equipment from other vendors.
• Spanning tree (STP): which bridge is the root, the path cost to it, port states and the topology change counter together with the time since the last change.

what to watch out for

• Without a time source the clock is worthless. Out of the box the switch reports "No time source" and stamps events with a date years in the past. Logs can be compared with anything only after SNTP is configured.
• The web panel does not save the configuration permanently. The save button sends nothing to the switch, and the message "You have unsaved configurations" remains. The command copy running-config startup-config on the command line works.
• SSH uses old algorithms that a modern client has disabled by default — they have to be allowed on the client side. The switch also ignores a command given together with the connection; only an interactive session works, and long output requires terminal datadump first.
• Without a DHCP server at startup it falls back to a factory address from a different subnet. When the switch powers an access point through which it has its own uplink, it starts faster than that access point — and disappears from the network, although it is working. A default gateway set while the switch is still in a different subnet is silently rejected.
• The fan table has four "not present" entries. This is a platform template, not a fault — the device has no fans.
• The standard uptime from the host resources table is always zero. Uptime is given by the system counter.

what we cannot read

• Temperature — it is neither in the standard tables nor in the vendor branch.
• Memory usage.
• VLAN names — the name table responds "no such object".
• Port layout from a vendor drawing — there is no front view for this model, and the series drawings show other models. An outline with true proportions is shown.

full parameter list

A full parameter list for this model is not here yet — the ones described above are those we have read and verified. A missing list does not mean the device exposes nothing more.