Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 111)

NOTE
When DHCP Assist is enabled on any port, Layer 2 broadcast packets are forwarded by the CPU.
Unknown unicast and multicast packets are still forwarded in hardware, although selective packets such
as IGMP are sent to the CPU for analysis. When DHCP Assist is not enabled, Layer 2 broadcast
packets are forwarded in hardware.
Configuring DHCP Assist
You can associate a gateway list with a port. You must configure a gateway list when DHCP Assist is
enabled on a BrocadeLayer 2 switch. The gateway list contains a gateway address for each subnet that
will be requesting addresses from a DHCP server. The list allows the stamping process to occur. Each
gateway address defined on the Layer 2 switch corresponds to an IP address of the Brocade router
interface or other router involved.
Up to eight addresses can be defined for each gateway list in support of ports that are multi-homed.
When multiple IP addresses are configured for a gateway list, the Layer 2 switch inserts the addresses
into the discovery packet in a round robin fashion.
Up to 32 gateway lists can be defined for each Layer 2 switch.
To create the configuration indicated in How DHCP Assist works on page 109, enter commands such
as the following.
device(config)# dhcp-gateway-list 1 10.95.5.1
device(config)# dhcp-gateway-list 2 10.95.6.1
device(config)# dhcp-gateway-list 3 10.95.1.1 10.95.5.1
device(config)# interface ethernet 2
device(config-if-e1000-2)# dhcp-gateway-list 1
device(config-if-e1000-2)# interface ethernet 8
device(config-if-e1000-8)# dhcp-gateway-list 3
device(config-if-e1000-8)# interface ethernet 14
device(config-if-e1000-14)# dhcp-gateway-list 2
Syntax:dhcp-gateway-list num ip-addr
IPv4 point-to-point GRE tunnels
NOTE
This feature is supported on FCX , ICX 6610, ICX 6450, ICX 6650, ICX 7750, and FastIron SX devices
only.
This section describes support for point-to-point Generic Routing Encapsulation (GRE) tunnels and how
to configure them on a Brocade device.
GRE tunnels support includes the following:
• IPv4 over GRE tunnels. IPv6 over GRE tunnels is not supported.
• Static and dynamic unicast routing over GRE tunnels
• Multicast routing over GRE tunnels
• Hardware forwarding of IP data traffic across a GRE tunnel.
• Path MTU Discovery (PMTUD)
Configuring DHCP Assist
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