Dell PowerConnect B-FCXs Configuration Manual page 836

26
Basic IP parameters and defaults – Layer 3 Switches
TABLE 144
Parameter
Time to Live
(TTL)
Directed
broadcast
forwarding
Directed
broadcast
mode
Source-routed
packet
forwarding
Internet Control
Message
Protocol (ICMP)
messages
ICMP Router
Discovery
Protocol (IRDP)
Reverse ARP
(RARP)
794
IP global parameters – Layer 3 Switches (Continued)
Description
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.
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.
Refer to Table 145
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.
A source-routed packet contains a list of IP
addresses through which the packet must pass to
reach its destination.
The Layer 3 Switch can send the following types of
ICMP messages:
•
Echo messages (ping messages)
•
Destination Unreachable messages
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. Refer to
page 796.
An IP mechanism a host can use to request an IP
address from a directly attached router when the
host boots.
Default
64 hops
Disabled
on page 796.
All ones
NOTE: If you enable
Enabled
Enabled
Disabled
Table 145 on
Enabled
PowerConnect B-Series FCX Configuration Guide
See page...
page 815
page 815
page 817
all-zeroes
directed
broadcasts,
all-ones directed
broadcasts
remain enabled.
page 816
page 817
page 832
page 834
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