Cisco SF350-24P 24-Port 10/100 PoE Managed Switch

Performance

Switching capacity and forwarding rate

All switches are wire speed and nonblocking

Model Name

Capacity in Millions of Packets per Second (mpps) (64-byte packets)

Switching Capacity in Gigabits per Second (Gbps)

SF350-08

1.19

1.6

SF352-08

4.17

5.6

SF352-08P

4.17

5.6

SF352-08MP

4.17

5.6

SF350-24

9.52

12.8

SF350-24P

9.52

12.8

SF350-24MP

9.52

12.8

SF350-48

13.09

17.6

SF350-48P

13.09

17.6

SF350-48MP

13.09

17.6

SG350-8PD

46.13

62.0

SG350-10

14.88

20.0

SG350-10P

14.88

20.0

SG350-10MP

14.88

20.0

SG355-10MP

14.88

20.0

SG350-10SFP

14.88

20.0

SG350-20

29.76

40.0

SG350-28

41.66

56.0

SG350-28P

41.66

56.0

SG350-28MP

41.66

56.0

SG350-28SFP

41.66

56.0

SG350-52

77.38

104.0

SG350-52P

77.38

104.0

SG350-52MP

77.38

104.0

Layer 2 Switching

Spanning Tree Protocol

Standard 802.1d Spanning Tree support

Fast convergence using 802.1w (Rapid Spanning Tree [RSTP]), enabled by default

Multiple Spanning Tree instances using 802.1s (MSTP); 8 instances are supported

Per-VLAN Spanning Tree Plus (PVST+) and Rapid PVST+ (RPVST+); 126 instances are supported

Port grouping/link aggregation

Support for IEEE 802.3ad Link Aggregation Control Protocol (LACP)

VLAN

Support for up to 4,094 VLANs simultaneously

Port-based and 802.1Q tag-based VLANs; MAC-based VLAN; protocol-based VLAN; IP subnet-based VLAN,

Management VLAN

Private VLAN with promiscuous, isolated, and community port

Private VLAN Edge (PVE), also known as protected ports, with multiple uplinks

Guest VLAN; unauthenticated VLAN

Dynamic VLAN assignment via RADIUS server along with 802.1x client authentication

CPE VLAN

Voice VLAN

Voice traffic is automatically assigned to a voice-specific VLAN and treated with appropriate levels of QoS

Auto voice capabilities deliver networkwide zero-touch deployment of voice endpoints and call control devices

Multicast TV VLAN

Multicast TV VLAN allows the single multicast VLAN to be shared in the network while subscribers remain in separate VLANs. This feature is also known as Multicast VLAN Registration (MVR)

VLAN Translation

Support for VLAN One-to-One Mapping. In VLAN One-to-One Mapping, on an edge interface C-VLANs are mapped to S-VLANs and the original C-VLAN tags are replaced by the specified S-VLAN

Q-in-Q

VLANs transparently cross a service provider network while isolating traffic among customers

Selective Q-in-Q

Selective Q-in-Q is an enhancement to the basic Q-in-Q feature and provides, per edge interface, multiple mappings of different C-VLANs to separate S-VLANs

Selective Q-in-Q also allows configuring of Ethertype (TPID) of the S-VLAN tag

Layer 2 protocol tunneling over Q-in-Q is also supported

Generic VLAN Registration Protocol (GVRP)/Generic Attribute Registration Protocol (GARP)

Generic VLAN Registration Protocol (GVRP) and Generic Attribute Registration Protocol (GARP) enable automatic propagation and configuration of VLANs in a bridged domain

Unidirectional Link Detection (UDLD)

UDLD monitors physical connection to detect unidirectional links caused by incorrect wiring or cable/port faults to prevent forwarding loops and blackholing of traffic in switched networks

Dynamic Host Configuration Protocol (DHCP) Relay at Layer 2

Relay of DHCP traffic to DHCP server in different VLAN; works with DHCP Option 82

Internet Group Management Protocol (IGMP) versions 1, 2, and 3 snooping

IGMP limits bandwidth-intensive multicast traffic to only the requesters; supports 2K multicast groups (source-specific multicasting is also supported)

IGMP Querier

IGMP querier is used to support a Layer 2 multicast domain of snooping switches in the absence of a multicast router

Head-Of-Line (HOL) blocking

HOL blocking prevention

Loopback Detection

Loopback detection provides protection against loops by transmitting loop protocol packets out of ports on which loop protection has been enabled. It operates independently of STP

Layer 3

IPv4 routing

Wirespeed routing of IPv4 packets

Up to 990 static routes and up to 128 IP interfaces

IPv6 routing

Wirespeed routing of IPv6 packets

Layer 3 Interface

Configuration of Layer 3 interface on physical port, LAG, VLAN interface, or loopback interface

Classless Interdomain Routing (CIDR)

Support for classless interdomain routing

Policy-Based Routing (PBR)

Flexible routing control to direct packets to different next hop based on IPv4 or IPv6 ACL

DHCP Server

Switch functions as an IPv4 DHCP server serving IP addresses for multiple DHCP pools/scopes

Support for DHCP options

DHCP relay at Layer 3

Relay of DHCP traffic across IP domains

User Datagram Protocol (UDP) relay

Relay of broadcast information across Layer 3 domains for application discovery or relaying of bootP/DHCP packets

Security

Secure Shell (SSH) Protocol

SSH is a secure replacement for Telnet traffic. SCP also uses SSH. SSH v1 and v2 are supported

Secure Sockets Layer (SSL)

SSL support: Encrypts all HTTPS traffic, allowing highly secure access to the browser-based management GUI in the switch

IEEE 802.1X (Authenticator role)

802.1X: RADIUS authentication and accounting, MD5 hash; guest VLAN; unauthenticated VLAN, single/multiple host mode and single/multiple sessions

Supports time-based 802.1X

Dynamic VLAN assignment

Web-based authentication

Web based authentication provides network admission control through web browser to any host devices and operating systems

STP Bridge Protocol Data Unit (BPDU) Guard

A security mechanism to protect the network from invalid configurations. A port enabled for BPDU Guard is shut down if a BPDU message is received on that port

STP Root Guard

This prevents edge devices not in the network administrator’s control from becoming Spanning Tree Protocol root nodes

STP loopback guard

Provides additional protection against Layer 2 forwarding loops (STP loops)

DHCP snooping

Filters out DHCP messages with unregistered IP addresses and/or from unexpected or untrusted interfaces. This prevents rogue devices from behaving as DHCP Servers

IP Source Guard (IPSG)

When IP Source Guard is enabled at a port, the switch filters out IP packets received from the port if the source IP addresses of the packets have not been statically configured or dynamically learned from DHCP snooping. This prevents IP Address Spoofing

Dynamic ARP Inspection (DAI)

The switch discards ARP packets from a port if there are no static or dynamic IP/MAC bindings or if there is a discrepancy between the source or destination addresses in the ARP packet. This prevents man-in-the-middle attacks

IP/MAC/Port Binding (IPMB)

The preceding features (DHCP Snooping, IP Source Guard, and Dynamic ARP Inspection) work together to prevent DOS attacks in the network, thereby increasing network availability

Secure Core Technology (SCT)

Makes sure that the switch will receive and process management and protocol traffic no matter how much traffic is received

Secure Sensitive Data (SSD)

A mechanism to manage sensitive data (such as passwords, keys, and so on) securely on the switch, populating this data to other devices, and secure autoconfig. Access to view the sensitive data as plaintext or encrypted is provided according to the user-configured access level and the access method of the user

Trustworthy systems

Trustworthy systems provide a highly secure foundation for Cisco products

Run-time defenses (Executable Space Protection [X-Space], Address Space Layout Randomization [ASLR], Built-In Object Size Checking [BOSC])

Private VLAN

Private VLAN provides security and isolation between switch ports, which helps ensure that users cannot snoop on other users’ traffic; supports multiple uplinks

Layer 2 isolation Private VLAN Edge (PVE) with community VLAN

PVE (also known as protected ports) provides Layer 2 isolation between devices in the same VLAN, supports multiple uplinks

Port security

Ability to lock source MAC addresses to ports and limits the number of learned MAC addresses

RADIUS/TACACS+

Supports RADIUS and TACACS authentication. Switch functions as a client

RADIUS accounting

The RADIUS accounting functions allow data to be sent at the start and end of services, indicating the amount of resources (such as time, packets, bytes, and so on) used during the session

Storm control

Broadcast, multicast, and unknown unicast

DoS prevention

Denial-Of-Service (DOS) attack prevention

Multiple user privilege levels in CLI

Level 1, 7, and 15 privilege levels

ACLs

Support for up to 1K rules

Drop or rate limit based on source and destination MAC, VLAN ID or IPv4 or IPv6 address, IPv6 flow label, protocol, port, Differentiated Services Code Point (DSCP)/IP precedence, TCP/UDP source and destination ports, 802.1p priority, Ethernet type, Internet Control Message Protocol (ICMP) packets, IGMP packets, TCP flag; ACL can be applied on both ingress and egress sides

Time-based ACLs supported

Quality of Service

Priority levels

8 hardware queues

Scheduling

Strict priority and Weighted Round-Robin (WRR)

Queue assignment based on DSCP and class of service (802.1p/CoS)

Class of service

Port based; 802.1p VLAN priority based; IPv4/v6 IP precedence/Type of Service (ToS)/DSCP based; Differentiated Services (DiffServ); classification and remarking ACLs, trusted QoS

Queue assignment based on DSCP and class of service (802.1p/CoS)

Rate limiting

Ingress policer; egress shaping and rate control; per VLAN, per port, and flow based; 2R3C policing

Congestion avoidance

A TCP congestion avoidance algorithm is required to minimize and prevent global TCP loss synchronization

Standards

Standards

IEEE 802.3 10BASE-T Ethernet, IEEE 802.3u 100BASE-TX Fast Ethernet, IEEE 802.3ab 1000BASE-T Gigabit Ethernet, IEEE 802.3ad Link Aggregation Control Protocol, IEEE 802.3z Gigabit Ethernet, IEEE 802.3x Flow Control, IEEE 802.1D (STP, GARP, and GVRP), IEEE 802.1Q/p VLAN, IEEE 802.1w Rapid STP, IEEE 802.1s Multiple STP, IEEE 802.1X Port Access Authentication, IEEE 802.3af, IEEE 802.3at, IEEE 802.1AB Link Layer Discovery Protocol, IEEE 802.3az Energy Efficient Ethernet, RFC 768, RFC 783, RFC 791, RFC 792, RFC 793, RFC 813, RFC 826, RFC 879, RFC 896, RFC 854, RFC 855, RFC 856, RFC 858, RFC 894, RFC 919, RFC 920, RFC 922, RFC 950, RFC 951, RFC 1042, RFC 1071, RFC 1123, RFC 1141, RFC 1155, RFC 1157, RFC 1213, RFC 1215, RFC 1286, RFC 1350, RFC 1442, RFC 1451, RFC 1493, RFC 1533, RFC 1541, RFC 1542, RFC 1573, RFC 1624, RFC 1643, RFC 1700, RFC 1757, RFC 1867, RFC 1907, RFC 2011, RFC 2012, RFC 2013, RFC 2030, RFC 2131, RFC 2132, RFC 2233, RFC 2576, RFC 2616, RFC 2618, RFC 2665, RFC 2666, RFC 2674, RFC 2737, RFC 2819, RFC 2863, RFC 3164, RFC 3176, RFC 3411, RFC 3412, RFC 3413, RFC 3414, RFC 3415, RFC 3416, RFC 4330

IPv6

IPv6

IPv6 host mode; IPv6 over Ethernet; Dual IPv6/IPv4 stack

IPv6 neighbor and router discovery (ND); IPv6 stateless address autoconfiguration; Path Maximum Transmission Unit (MTU) discovery

Duplicate Address Detection (DAD); ICMP version 6

DHCPv6 stateful client

IPv6 over IPv4 network with Intrasite Automatic Tunnel Addressing Protocol (ISATAP) tunnel support

USGv6 and IPv6 Gold Logo certified

IPv6 QoS

Prioritize IPv6 packets in hardware

IPv6 ACL

Drop or rate limit IPv6 packets in hardware

IPv6 First Hop Security

RA guard

ND inspection

DHCPv6 guard

Neighbor binding table (snooping and static entries)

Neighbor binding integrity check

Multicast Listener Discovery (MLD v1/2) snooping

Deliver IPv6 multicast packets only to the required receivers

IPv6 applications

Web/SSL, Telnet server/SSH, ping, traceroute, Simple Network Time Protocol (SNTP), Trivial File Transfer Protocol (TFTP), SNMP, RADIUS, syslog, DNS client, Telnet Client, DHCP Client, DHCP Autoconfig, IPv6 DHCP Relay, TACACS+

IPv6 RFCs supported

RFC 4443 (which obsoletes RFC2463): ICMP version 6

RFC 4291 (which obsoletes RFC 3513): IPv6 address architecture

RFC 4291: IPv6 addressing architecture

RFC 2460: IPv6 specification

RFC 4861 (which obsoletes RFC 2461): neighbor discovery for IPv6

RFC 4862 (which obsoletes RFC 2462): IPv6 stateless address autoconfiguration

RFC 1981: path MTU discovery

RFC 4007: IPv6 scoped address architecture

RFC 3484: default address selection mechanism

RFC 5214 (which obsoletes RFC 4214): ISATAP tunneling

RFC 4293: MIB IPv6: textual conventions and general group

RFC 3595: textual conventions for IPv6 flow label

Management

Web user interface

Built-in switch configuration utility for easy browser-based device configuration (HTTP/HTTPS)

Supports simple and advanced mode, configuration, wizards, customizable dashboard, system maintenance, monitoring, online help, and universal search

Smart Network Application

Smart Network Application (SNA) is an innovative network-level monitoring and management tool embedded in Cisco 100 to 500 Series switches. It can discover network topology, display link status, monitor events, apply configurations, and upgrade software images across multiple switches in the network

(Note: Management of your network using Smart Network Application requires the use of either a 350, 350X, or 550X Series switch model as a part of your network)

SNMP

SNMP versions 1, 2c, and 3 with support for traps, and SNMP version 3 User-based Security Model (USM)

Standard MIBs

lldp-MIB

lldpextdot1-MIB

lldpextdot3-MIB

lldpextmed-MIB

rfc2674-MIB

rfc2575-MIB

rfc2573-MIB

rfc2233-MIB

rfc2013-MIB

rfc2012-MIB

rfc2011-MIB

RFC-1212

RFC-1215

SNMPv2-CONF

SNMPv2-TC

p-bridge-MIB

q-bridge-MIB

rfc1389-MIB

rfc1493-MIB

rfc1611-MIB

rfc1612-MIB

rfc1850-MIB

rfc1907-MIB

rfc2571-MIB

rfc2572-MIB

rfc2574-MIB

rfc2576-MIB

rfc2613-MIB

rfc2665-MIB

rfc2668-MIB

rfc2737-MIB

rfc2925-MIB

rfc3621-MIB

rfc4668-MIB

rfc4670-MIB

trunk-MIB

tunnel-MIB

udp-MIB

draft-ietf-bridge-8021x-MIB

draft-ietf-bridge-rstpmib-04-MIB

draft-ietf-hubmib-etherif-mib-v3-00-MIB

draft-ietf-syslog-device-MIB

ianaaddrfamnumbers-MIB

ianaifty-MIB

ianaprot-MIB

inet-address-MIB

ip-forward-MIB

ip-MIB

RFC1155-SMI

RFC1213-MIB

SNMPv2-MIB

SNMPv2-SMI

SNMPv2-TM

RMON-MIB

rfc1724-MIB

dcb-raj-DCBX-MIB-1108-MIB

rfc1213-MIB

rfc1757-MIB

Private MIBs

CISCOSB-lldp-MIB CISCOSB-

brgmulticast-MIB CISCOSB-

bridgemibobjects-MIB

CISCOSB-bonjour-MIB

CISCOSB-dhcpcl-MIB

CISCOSB-MIB

CISCOSB-wrandomtaildrop-MIB

CISCOSB-traceroute-MIB

CISCOSB-telnet-MIB

CISCOSB-stormctrl-MIB

CISCOSB-ssh-MIB

CISCOSB-socket-MIB

CISCOSB-sntp-MIB

CISCOSB-smon-MIB

CISCOSB-phy-MIB

CISCOSB-multisessionterminal-MIB

CISCOSB-mri-MIB

CISCOSB-jumboframes-MIB

CISCOSB-gvrp-MIB

CISCOSB-endofmib-MIB

CISCOSB-dot1x-MIB

CISCOSB-deviceparams-MIB

CISCOSB-cli-MIB

CISCOSB-cdb-MIB

CISCOSB-brgmacswitch-MIB

CISCOSB-3sw2swtables-MIB

CISCOSB-smartPorts-MIB

CISCOSB-tbi-MIB

CISCOSB-macbaseprio-MIB

CISCOSB-policy-MIB

CISCOSB-env_mib

CISCOSB-sensor-MIB

CISCOSB-aaa-MIB

CISCOSB-application-MIB

CISCOSB-bridgesecurity-MIB

CISCOSB-copy-MIB

CISCOSB-CpuCounters-MIB

CISCOSB-Custom1BonjourService-MIB

CISCOSB‑dhcp-MIB

CISCOSB-dlf-MIB

CISCOSB-dnscl-MIB

CISCOSB-embweb-MIB

CISCOSB-fft-MIB

CISCOSB-file-MIB

CISCOSB-greeneth-MIB

CISCOSB-interfaces-MIB

CISCOSB-interfaces_recovery-MIB

CISCOSB-ip-MIB

CISCOSB-iprouter-MIB

CISCOSB-ipv6-MIB

CISCOSB-mnginf-MIB

CISCOSB-lcli-MIB

CISCOSB-localization-MIB

CISCOSB-mcmngr-MIB

CISCOSB-mng-MIB

CISCOSB-physdescription-MIB

CISCOSB-Poe-MIB

CISCOSB-protectedport-MIB

CISCOSB-rmon-MIB

CISCOSB-rs232-MIB

CISCOSB-SecuritySuite-MIB

CISCOSB-snmp-MIB

CISCOSB-specialbpdu-MIB

CISCOSB-banner-MIB

CISCOSB-syslog-MIB

CISCOSB-TcpSession-MIB

CISCOSB-traps-MIB

CISCOSB-trunk-MIB

CISCOSB-tuning-MIB

CISCOSB-tunnel-MIB

CISCOSB-udp-MIB

CISCOSB-vlan-MIB

CISCOSB-ipstdacl-MIB

CISCOSB-eee-MIB

CISCOSB-ssl-MIB

CISCOSB-qosclimib-MIB

CISCOSB-digitalkeymanage-MIB

CISCOSB-tbp-MIB

CISCOSMB-MIB

CISCOSB-secsd-MIB

CISCOSB-draft-ietf-entmib-sensor-MIB

CISCOSB-draft-ietf-syslog-device-MIB

CISCOSB-rfc2925-MIB

CISCO-SMI-MIB

CISCOSB-DebugCapabilities-MIB

CISCOSB-CDP-MIB

CISCOSB-vlanVoice-MIB

CISCOSB-EVENTS-MIB

CISCOSB-sysmng-MIB

CISCOSB-sct-MIB

CISCO-TC-MIB

CISCO-VTP-MIB

CISCO-CDP-MIB

Remote Monitoring (RMON)

Embedded RMON software agent supports 4 RMON groups (history, statistics, alarms, and events) for enhanced traffic management, monitoring, and analysis

IPv4 and IPv6 dual stack

Coexistence of both protocol stacks to ease migration

Firmware upgrade

Port mirroring

Traffic on a port can be mirrored to another port for analysis with a network analyzer or RMON probe. Up to 8 source ports can be mirrored to one destination port. A single session is supported

VLAN mirroring

Traffic from a VLAN can be mirrored to a port for analysis with a network analyzer or RMON probe. Up to 8 source VLANs can be mirrored to one destination port. A single session is supported

DHCP (options 12, 66, 67, 82, 129, and 150)

DHCP options facilitate tighter control from a central point (DHCP server) to obtain IP address, autoconfiguration (with configuration file download), DHCP relay, and hostname

Secure Copy (SCP)

Securely transfer files to and from the switch

Autoconfiguration with Secure Copy (SCP) file download

Enables secure mass deployment with protection of sensitive data

Text-editable config files

Config files can be edited with a text editor and downloaded to another switch, facilitating easier mass deployment

Smartports

Simplified configuration of QoS and security capabilities

Auto Smartports

Applies the intelligence delivered through the Smartport roles and applies it automatically to the port based on the devices discovered over Cisco Discovery Protocol or LLDP-MED. This facilitates zero-touch deployments

Textview CLI

Scriptable command-line interface. A full CLI as well as a menu-based CLI is supported. User privilege levels 1, 7, and 15 are supported for the CLI

Cloud services

Support for Cisco FindIT Network Manager and Cisco Active Advisor

Embedded Probe for FindIT Network Manager

Support for embedded FindIT Network Probe running on the switch. Eliminates the need to set up a separate hardware or virtual machine for the FindIT Network Probe on site

Cisco Network Plug and Play (PnP) agent

The Cisco Network Plug and Play solution provides a simple, secure, unified, and integrated offering to ease new branch or campus device rollouts or for provisioning updates to an existing network. The solution provides a unified approach to provision Cisco routers, switches, and wireless devices with a near-zero-touch deployment experience

Supports Cisco PnP Connect

Localization

Localization of GUI and documentation into multiple languages

Login banner

Configurable multiple banners for web as well as CLI

Other management

Traceroute; single IP management; HTTP/HTTPS; SSH; RADIUS; port mirroring; TFTP upgrade; DHCP client; BOOTP; SNTP; Xmodem upgrade; cable diagnostics; ping; syslog; Telnet client (SSH secure support); automatic time settings from Management Station

Time-based port operation

Link up or down based on user-defined schedule (when the port is administratively up)

Time-based PoE

Capability for power to be on or off based on a user-defined schedule to save energy

Power Efficiency

Energy Detect

Automatically turns power off on Gigabit Ethernet and 10/100 RJ-45 port when detecting link down. Active mode is resumed without loss of any packets when the switch detects the link up

Cable length detection

Adjusts the signal strength based on the cable length for Gigabit Ethernet models. Reduces the power consumption for shorter cables

EEE Compliant (802.3az)

Supports IEEE 802.3az on all copper Gigabit Ethernet ports

Disable port LEDs

LEDs can be manually turned off to save on energy

Time-based port operation

Link up or down based on user-defined schedule (when the port is administratively up)

Time-based PoE

Capability for power to be on or off based on a user-defined schedule to save energy

General

Jumbo frames

Frame sizes up to 9K bytes. The default MTU is 2K bytes

MAC table

16K addresses

Discovery

Bonjour

The switch advertises itself using the Bonjour protocol

Link Layer Discovery Protocol (LLDP) (802.1ab) with LLDP‑MED extensions

LLDP allows the switch to advertise its identification, configuration, and capabilities to neighboring devices that store the data in a MIB. LLDP-MED is an enhancement to LLDP that adds the extensions needed for IP phones

Cisco Discovery Protocol

The switch advertises itself using the Cisco Discovery Protocol. It also learns the connected device and its characteristics via Cisco Discovery Protocol

Power over Ethernet (PoE)

802.3af PoE, 802.3at PoE+, or 60W PoE are delivered over the RJ-45 ports within the listed power budgets

The following switches support 802.3at PoE+, 802.3af PoE, and Cisco prestandard (legacy) PoE on any of the RJ45 network ports. 60W PoE is also supported on selected RJ-45 network ports

Maximum power of 60W is delivered to any of the 60W PoE ports, and maximum power of 30W is delivered to any of the other RJ45 network ports, until the PoE budget for the switch is reached

The total power available for PoE per switch is as follows

Model Name

Power Dedicated to PoE

Number of Ports That Support PoE

SF352-08P

62W

8

SF352-08MP

128W

8

SF350-24P

185W

24 (4 support 60W PoE)

SF350-24MP

375W

24 (4 support 60W PoE)

SF350-48P

382W

48 (8 support 60W PoE)

SF350-48MP

740W

48 (8 support 60W PoE)

SG350-8PD

124W

8

SG350-10P

62W

8

SG355-10P

62W

8

SG350-10MP

124W

8

SG350-28P

195W

24 (4 support 60W PoE)

SG350-28MP

382W

24 (4 support 60W PoE)

SG350-52P

375W

48 (8 support 60W PoE)

SG350-52MP

740W

48 (8 support 60W PoE)

PoE powered device and PoE passthrough

In addition to AC power, compact switch models can work as PoE powered devices and be powered by PoE switches connected to the uplink ports. The switch can also pass through the power to downstream PoE end devices if required

Maximum of 60W can be drawn per uplink port if the peer PoE switch supports 60W PoE. When multiple uplink ports are connected to PoE switches, the power drawn from these ports is combined

When AC power is connected and functioning properly, it will have priority over the PoE powered device function. The PoE powered device function will then act as a backup power source to the AC power. The PoE powered device function will be the primary power source for the switch if AC power is not connected