Changing The Ttl Threshold; Dhcp Assist Configuration - Brocade Communications Systems FastIron SX 800 Configuration Manual

Configuring IP parameters - Layer 2 switches

Changing the TTL threshold

The time to live (TTL) threshold prevents routing loops by specifying the maximum number of router hops an IP packet originated by the
Layer 2 switch can travel through. Each device capable of forwarding IP that receives the packet decrements (decreases) the packet TTL
by one. If a router receives a packet with a TTL of 1 and reduces the TTL to zero, the router drops the packet.
The default TTL is 64. You can change the ttl-threshold to a value from 1 through 255.
To modify the TTL threshold to 25, enter the following commands.
device(config)# ip ttl 25
device(config)# exit
Syntax: ip ttl ttl-threshold

DHCP Assist configuration

DHCP Assist allows a Brocade Layer 2 switch to assist a router that is performing multi-netting on its interfaces as part of its DHCP
relay function.
DHCP Assist ensures that a DHCP server that manages multiple IP subnets can readily recognize the requester IP subnet, even when
that server is not on the client local LAN segment. The Brocade Layer 2 switch does so by stamping each request with its IP gateway
address in the DHCP discovery packet.
NOTE
Brocade Layer 2 switches provide BootP/DHCP assistance by default on an individual port basis. Refer to
address used for stamping BootP and DHCP requests
By allowing multiple subnet DHCP requests to be sent on the same wire, you can reduce the number of router ports required to support
secondary addressing as well as reduce the number of DHCP servers required, by allowing a server to manage multiple subnet address
assignments.
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on page 83.
Changing the IP
FastIron Ethernet Switch Layer 3 Routing
53-1003627-04