Table of Contents
Advertisement
Configuring IP Addressing
Enable Proxy ARP
By default, the switch uses proxy ARP to help hosts learn MAC addresses of hosts on other networks or
subnets.
Beginning in privileged EXEC mode, follow these steps to enable proxy ARP if it has been disabled:
Command
Step 1
configure terminal
Step 2
interface interface-id
Step 3
ip proxy-arp
Step 4
end
Step 5
show ip interface [interface-id]
Step 6
copy running-config startup-config
To disable proxy ARP on the interface, use the no ip proxy-arp interface configuration command.
Routing Assistance When IP Routing is Disabled
These mechanisms allow the switch to learn about routes to other networks when it does not have IP
routing enabled:
•
•
•
Proxy ARP
Proxy ARP, the most common method for learning about other routes, enables an Ethernet host with no
routing information to communicate with hosts on other networks or subnets. The host assumes that all
hosts are on the same local Ethernet and that they can use ARP to learn their MAC addresses. If a switch
receives an ARP request for a host that is not on the same network as the sender, the switch evaluates
whether it has the best route to that host. If it does, it sends an ARP reply packet with its own Ethernet
MAC address. The host that sent the request then sends the packet to the switch, which forwards it to the
intended host. Proxy ARP treats all networks as if they are local and performs ARP requests for every
IP address.
Proxy ARP is enabled by default. To enable it after it has been disabled, see the
section on page
Default Gateway
Another method for locating routes is to define a default router or default gateway. All nonlocal packets
are sent to this router, which either routes them appropriately or returns an IP Control Message Protocol
(ICMP) redirect message, identifying the local router that the host should use. The switch caches the
redirect messages and forwards each packet as efficiently as possible. This method cannot detect when
the default router has failed or is unavailable.
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
39-12
Proxy ARP, page 39-12
Default Gateway, page 39-12
ICMP Router Discovery Protocol (IRDP), page 39-13
39-12. Proxy ARP works as long as other routers support it.
Purpose
Enter global configuration mode.
Enter interface configuration mode, and specify the Layer 3
interface to configure.
Enable proxy ARP on the interface.
Return to privileged EXEC mode.
Verify the configuration on the interface or all interfaces.
(Optional) Save your entries in the configuration file.
Chapter 39
Configuring IP Unicast Routing
"Enable Proxy ARP"
OL-13270-06
Hide quick links:
Advertisement
Chapters
Table of Contents
Troubleshooting
