Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide User Manual
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IP global parameters - Layer 3 Switches (Continued)
TABLE 2
Parameter
Description
Default
Time to Live (TTL)
The maximum number of routers (hops) through which a packet
can pass before being discarded. Each router decreases a packet
TTL by 1 before forwarding the packet. If decreasing the TTL
causes the TTL to be 0, the router drops the packet instead of
forwarding it.
64 hops
Directed broadcast
forwarding
A directed broadcast is a packet containing all ones (or in some
cases, all zeros) in the host portion of the destination IP address.
When a router forwards such a broadcast, it sends a copy of the
packet out each of its enabled IP interfaces.
NOTE
You also can enable or disable this parameter on an individual
interface basis.
Disabled
Directed broadcast
mode
The packet format the router treats as a directed broadcast. The
following formats can be directed broadcast:
• All ones in the host portion of the packet destination address.
• All zeroes in the host portion of the packet destination address.
All ones
NOTE
If you enable all-
zeroes directed
broadcasts, all-ones
directed broadcasts
remain enabled.
Source-routed
packet forwarding
A source-routed packet contains a list of IP addresses through
which the packet must pass to reach its destination.
Enabled
Internet Control
Message Protocol
(ICMP) messages
The Brocade Layer 3 Switch can send the following types of ICMP
messages:
• Echo messages (ping messages)
• Destination Unreachable messages
Enabled
ICMP Router
Discovery Protocol
(IRDP)
An IP protocol a router can use to advertise the IP addresses of its
router interfaces to directly attached hosts. You can enable or
disable the protocol, and change the following protocol
parameters:
• Forwarding method (broadcast or multicast)
• Hold time
• Maximum advertisement interval
• Minimum advertisement interval
• Router preference level
NOTE
You also can enable or disable IRDP and configure the
parameters on an individual interface basis.
Disabled
Reverse ARP
(RARP)
An IP mechanism a host can use to request an IP address from a
directly attached router when the host boots.
Enabled
IP Configuration
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FastIron Ethernet Switch Layer 3 Routing Configuration Guide
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