Management and IP Interfaces
The switch operates as a Layer 2 VLAN-aware switch, and has no routing capabilities. The 200 Series switches do not have Layer 3 capabilities.
Layer 2 IP Addressing
The switch has a single IP address in the management VLAN. This IP address and the default gateway can be configured manually, or by DHCP. The static IP address and default gateway are configured on the IPv4 Interface page. The switch uses the default gateway, if configured, to communicate with devices that are not in the same IP subnet as the switch. By default, VLAN 1 is the management VLAN, but this can be modified. The switch can only be reached at the configured IP address through its management VLAN.
The factory default setting of the IP address configuration is DHCP. This means that the switch acts as a DHCP client, and sends out a DHCP request during boot up.
If the switch receives a DHCP response from the DHCP server with an IP address, it sends Address Resolution Protocol (ARP) packets to confirm that the IP address is unique. If the ARP response shows that the IP address is in use, the switch sends a DHCPDECLINE message to the offering DHCP server, and sends another DHCPDISCOVER packet that restarts the process.
If the switch does not receive a DHCP response in 60 seconds, it continues to send DHCPDISCOVER queries, and adopts the default IP address: 192.168.1.254/ 24.
IP address collisions occur when the same IP address is used in the same IP subnet by more than one device. Address collisions require administrative actions on the DHCP server and/or the devices that collide with the switch.
When a VLAN is configured to use dynamic IP addresses, the switch issues DHCP requests until it is assigned an IP address from a DHCP server. The management VLAN can be configured with a static or dynamic IP address. The IP subnets to which these IP addresses belong are known as directly connected/attached IP subnets.
The IP address assignment rules for the switch are as follows:
- Unless the switch is configured with a static IP address, it issues DHCP queries until a response is received from a DHCP server.
- If the IP address on the switch is changed, the switch issues gratuitous ARP packets to the corresponding VLAN to check IP address collisions. This rule also applies when the switch reverts to the default IP address.
- The system status LED changes to solid green when a new unique IP address is received from the DHCP server. If a static IP address has been set, the system status LED also changes to solid green. The LED flashes when the switch is acquiring an IP address and is currently using the factory default IP address 192.168.1.254.
- The same rules apply when a client must renew the lease, prior to its expiration date through a DHCPREQUEST message.
- When no statically defined or DHCP-acquired IP address is available, the default IP address is used. When the other IP addresses becomes available, the addresses are automatically used. The default IP address is always on the management VLAN.