Dhcp servers, Dhcp user class options, Ddns – Brocade Mobility RFS7000-GR Controller System Reference Guide (Supporting software release 4.1.0.0-040GR and later) User Manual
Page 30: Vlan enhancements
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Brocade Mobility RFS7000-GR Controller System Reference Guide
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Software overview
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DHCP servers
Dynamic Host Configuration Protocol (DHCP) allows hosts on an IP network to request and be
assigned IP addresses as well as discover information about the network to which they are
attached. Each subnet may be configured with its own address pool. Whenever a DHCP client
requests an IP address, the DHCP server assigns an IP address from that subnet’s address pool.
When a DHCP server allocates an address for a DHCP client, the client is assigned a lease, which
expires after an pre-determined interval. Before a lease expires, clients (to which leases are
assigned) are expected to renew them to continue to use the addresses. Once the lease expires,
the client is no longer permitted to use the leased IP address. For information on defining the
switch DHCP configuration, see
DHCP user class options
A DHCP Server groups clients based on defined user-class option values. Clients with a defined set
of user-class values are segregated by class. The DHCP Server can associate multiple classes to
each pool. Each class in a pool is assigned an exclusive range of IP addresses.
DHCP clients are compared against classes. If the client matches one of the classes assigned to
the pool, it receives an IP address from the range assigned to the class. If the client doesn't match
any of the classes in the pool, it receives an IP address from a default pool range (if defined).
Multiple IP addresses for a single VLAN allow the configuration of multiple IP addresses, each
belonging to different subnet. Class configuration allows a DHCP client to obtain an address from
the first pool to which the class is assigned. For more information, see
DDNS
Dynamic DNS (DDNS) keeps a domain name linked to a changing IP address. Typically, when a user
connects to a network, the user’s ISP assigns it an unused IP address from a pool of IP addresses.
This address is only valid for a short period. Dynamically assigning IP addresses increases the pool
of assignable IP addresses. DNS maintains a database to map a given name to an IP address used
for communication on the Internet. The dynamic assignment of IP addresses makes it necessary to
update the DNS database to reflect the current IP address for a given name. Dynamic DNS updates
the DNS database to reflect the correct mapping of a given name to an IP address.
VLAN enhancements
The switch has incorporated the following VLAN enhancements:
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Network interfaces operate in either trunk or access modes.
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A network interface in access mode can only send and receive untagged packets.
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A trunk port can now receive both tagged and untagged packets. Each ethernet port is
assigned a native VLAN.