Configuration Guide User guide

160 BigIron RX Series Configuration Guide
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Basic IP parameters and defaults
7
TABLE 46 IP global parameters
Parameter Description Default See page...
IP state The Internet Protocol, version 4 Enabled
NOTE: You cannot disable
IP.
n/a
IP address and mask
notation
Format for displaying an IP address and its network mask
information. You can enable one of the following:
• Class-based format; example: 192.168.1.1 255.255.255.0
• Classless Interdomain Routing (CIDR) format; example:
192.168.1.1/24
Class-based
NOTE: Changing this
parameter affects
the display of IP
addresses, but you
can enter addresses
in either format
regardless of the
display setting.
page 164
Router ID The value that routers use to identify themselves to other routers
when exchanging route information. OSPF and BGP4 use router
IDs to identify routers. RIP does not use the router ID.
The IP address configured on
the lowest-numbered
loopback interface.
If no loopback interface is
configured, then the
lowest-numbered IP address
configured on the device.
page 185
IP Maximum
Transmission Unit
(MTU)
The maximum length an Ethernet packet can be without being
fragmented.
1500 bytes for Ethernet II
encapsulation
1492 bytes for SNAP
encapsulation
page 183
Address Resolution
Protocol (ARP)
A standard IP mechanism that routers use to learn the Media
Access Control (MAC) address of a device on the network. The
router sends the IP address of a device in the ARP request and
receives the device’s MAC address in an ARP reply.
Enabled page 189
ARP rate limiting Lets you specify a maximum number of ARP packets the device
will accept each second. If the device receives more ARP packets
than you specify, the device drops additional ARP packets for the
remainder of the one-second interval.
Disabled page 190
ARP age The amount of time the device keeps a MAC address learned
through ARP in the device’s ARP cache. The device resets the
timer to zero each time the ARP entry is refreshed and removes
the entry if the timer reaches the ARP age.
NOTE: You also can change the ARP age on an individual
interface basis. Refer to Table 47 on page 162.
Ten minutes page 192
Proxy ARP An IP mechanism a router can use to answer an ARP request on
behalf of a host, by replying with the router’s own MAC address
instead of the host’s.
Disabled page 193
Static ARP entries An ARP entry you place in the static ARP table. Static entries do
not age out.
2048 page 193
Time to Live (TTL) The maximum number of routers (hops) through which a packet
can pass before being discarded. Each router decreases a
packet’s 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 page 197