Configuring IP Information
Management and IP Interfaces
Cisco 500 Series Stackable Managed Switch Administration Guide
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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. In Layer 2 mode,
only the management VLAN can be configured with a static or dynamic IP
address. In Layer 3 mode, up to 32 interfaces (ports, LAGs, and/or VLANs) on the
switch 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:
•
When in Layer 2 mode, unless the switch is configured with a static IP
address, it issues DHCP queries until a response is received from the 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 become available,
the addresses are automatically used. The default IP address is always on
the management VLAN.
Layer 3 IP Addressing
In Layer 3 mode, the switch can have multiple IP addresses. Each IP address can
be assigned to specified ports, LAGs, or VLANs. These IP addresses are
configured in the
IPv4 Interface
page in Layer 3 mode. This provides more
network flexibility than the Layer 2 mode, in which only a single IP address can be
configured. Operating in Layer 3 mode, the switch can be reached at all its IP
addresses from the corresponding interfaces.
A predefined, default route is not provided in Layer 3 mode. To remotely manage
the switch, a default route must be defined. All DHCP-assigned default gateways
are stored as default routes. In addition, you can manually define default routes.
This is defined in the
IPv4 Static Routes
page.
