Users Guide

1114 IP Routing
Default gateway The switch supports a single default gateway. A
manually configured default gateway is more
preferable than a default gateway learned from a
DHCP server.
ARP table The switch maintains an ARP table that maps an
IP address to a MAC address. Static ARP entries
can be created in the table and various ARP table
settings can be managed, such as the aging time of
dynamically-learned entries.
ICMP Router Discovery
Protocol (IRDP)
Hosts can use IRDP to identify operational routers
on the subnet. Routers periodically advertise their
IP addresses. Hosts listen for these advertisements
and discover the IP addresses of neighboring
routers.
Routing table entries The following route types can be configured in the
routing table:
• Default: The default route is the route the switch
will use to send a packet if the routing table does
not contain a longer matching prefix for the
packet's destination.
• Static: A static route is a route that you manually
add to the routing table.
• Static Reject: Packets that match a reject route
are discarded instead of forwarded. The router
may send an ICMP Destination Unreachable
message.
Route preferences The common routing table collects static, local,
and dynamic (routing protocol) routes. When
there is more than one route to the same
destination prefix, the routing table selects the
route with the best (lowest) route preference.
Table 29-1. IP Routing Features (Continued)
Feature Description