Configuring IP
December 2005 © Foundry Networks, Inc. 16 - 11
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. See Table 16.3 on
page 16-13.
Disabled 16-29
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’s
destination address.
• All zeroes in the host portion of the packet’s
destination address.
All ones
Note: If you enable
all-zeroes directed
broadcasts, all-ones
directed broadcasts
remain enabled.
16-30
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 16-30
Internet Control
Message
Protocol (ICMP)
messages
The Foundry Layer 3 Switch can send the following
types of ICMP messages:
• Echo messages (ping messages)
• Destination Unreachable messages
Enabled 16-31
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. See Table 16.3 on page 16-13.
Disabled 16-44
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 16-45
Static RARP
entries
An IP address you place in the RARP table for RARP
requests from hosts.
Note: You must enter the RARP entries manually.
The Layer 3 Switch does not have a mechanism for
learning or dynamically generating RARP entries.
No entries 16-46
Table 16.2: IP Global Parameters – Layer 3 Switches (Continued)
Parameter Description Default See page...