OmniSwitch os6900, Руководство по настройке сети, Страница: 346 / 942

IP Forwarding Configuring IP
page 15-12 OmniSwitch AOS Release 7 Network Configuration Guide June 2013
Creating a Default Route
A default route can be configured for packets destined for networks that are unknown to the switch. Use
the
ip static-route command to create a default route. Specify a default route of 0.0.0.0 with a subnet
mask of 0.0.0.0 and the IP address of the next hop (gateway). For example, to create a default route
through gateway 171.11.2.1 you would enter:
-> ip static-route 0.0.0.0 mask 0.0.0.0 gateway 171.11.2.1
Specifying the length of the mask in bits is also supported. For example, the above default route is also
configurable using the following command:
-> ip static-route 0.0.0.0/0 gateway 171.11.2.1
Note. You cannot create a default route by using the EMP port as a gateway.
Configuring Address Resolution Protocol (ARP)
To send packets on a locally connected network, the switch uses ARP to match the IP address of a device
with its physical (MAC) address. To send a data packet to a device with which it has not previously
communicated, the switch first broadcasts an ARP request packet. The ARP request packet requests the
Ethernet hardware address corresponding to an Internet address. All hosts on the receiving Ethernet
receive the ARP request, but only the host with the specified IP address responds. If present and
functioning, the host with the specified IP address responds with an ARP reply packet containing its
hardware address. The switch receives the ARP reply packet, stores the hardware address in its ARP cache
for future use, and begins exchanging packets with the receiving device.
The switch stores the hardware address in its ARP cache (ARP table). The table contains a listing of IP
addresses and their corresponding translations to MAC addresses. Entries in the table are used to translate
32-bit IP addresses into 48-bit Ethernet or IEEE 802.3 hardware addresses. Dynamic addresses remain in
the table until they time out. You can set this time-out value and you can also manually add or delete
permanent addresses to/from the table.
Adding a Permanent Entry to the ARP Table
As described above, dynamic entries remain in the ARP table for a specified time period before they are
automatically removed. However, you can create a permanent entry in the table.
Use the vrf command to add a permanent entry to the ARP table. Enter the IP address of the entry
followed by its physical (MAC) address. For example, to create an entry for IP address 171.11.1.1 with a
corresponding physical address of 00:05:02:c0:7f:11, you would enter:
-> arp 171.11.1.1 00:05:02:c0:7f:11
Configuring a permanent ARP entry with a multicast address is also supported. For example, the
following command creates a permanent multicast ARP entry:
-> arp 2.2.3.40 01:4a:22:03:44:5c
When configuring a static multicast ARP entry, do not use any of the following multicast addresses:
01:00:5E:00:00:00 to 01:00:5E:7F:FF:FF
01:80:C2:XX.XX.XX
33:33:XX:XX:XX:XX