Cisco WS-C2960-24PC-L Software Guide - Page 416
Configuring Permanent and Static ARP Entries
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Configuring Permanent and Static ARP Entries Chapter 27 Administering the Switch This example shows how to define two IP aliases, sparc, which refers to IP address 172.20.52.3, and cat4003, which refers to IP address 172.20.52.71. This example also shows how to verify the currently defined IP aliases: Console> (enable) set ip alias sparc 172.20.52.3 IP alias added. Console> (enable) set ip alias cat4003 172.20.52.71 IP alias added. This example shows what happens when you use the IP aliases with the ping command: Console> (enable) show ip alias default 0.0.0.0 sparc 172.20.52.3 cat5509 172.20.52.71 Console> (enable) ping sparc sparc is alive Console> (enable) ping cat4003 cat4003 is alive Console> (enable) Configuring Permanent and Static ARP Entries To enable your Catalyst LAN switch to communicate with devices that do not respond to Address Resolution Protocol (ARP) requests, you can configure a static or permanent ARP entry that maps the IP addresses of those devices to their MAC addresses. You can configure an ARP entry so that it does not age out, by configuring it as either static or permanent. When you configure a static ARP entry using the set arp static command, the entry is removed from the ARP cache after a system reset. When you configure a permanent ARP by using the set arp permanent command, the ARP entry is retained even after a system reset. Because most hosts support dynamic resolution, you usually do not need to specify static or permanent ARP cache entries. When a device does not respond to ARP requests, you can configure an ARP entry to be statically or permanently entered into the ARP cache so that those devices can still be reached. To configure a static or permanent ARP entry, perform this task in privileged mode: Step 1 Step 2 Step 3 Task Command Configure a static or permanent ARP entry. set arp [dynamic | permanent | static] {ip_addr hw_addr} (Optional) Specify the ARP aging time. set arp agingtime seconds Verify the ARP configuration. show arp This example shows how to define a static ARP entry: Console> (enable) set arp static 20.1.1.1 00-80-1c-93-80-40 Static ARP entry added as 20.1.1.1 at 00-80-1c-93-80-40 on vlan 1 Console> (enable) This example shows how to define a permanent ARP entry: Console> (enable) set arp permanent 10.1.1.1 00-80-1c-93-80-60 Permanent ARP entry added as 10.1.1.1 at 00-80-1c-93-80-60 on vlan 1 Console> (enable) 27-8 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01
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