I found that my arp table is very big and it consume about 3% CPU of my 1721. Will "no ip proxy-arp" command decrease my arp table? What did "ip proxy-arp" do? I know it is enabled by default, if I turn it off, will it be affect my Internet and Intranet connection? Any idea will be appreciated. Thanks!
Also check your route statements, if you have a default route pointing to a broadcast interface (ip route 0.0.0.0 0.0.0.0 ethernet 0) this will increase your arp table, if possible, change the route statement to use a next hop address.
If the 1721's ARP table is very large, it's probably because another device is doing proxy-arp for the 1721 rather than the 1721 itself doing proxy-arp. As mentioned above, static routes (especially static default routes) pointing to Ethernet interfaces rather than specific next-hop addresses are a common cause of this. A router with such a route has to ARP for every destination that uses the default route; a device with proxy-arp enabled then responds to all of these ARP requests with its MAC address so that it can forward the packets appropriately.
So, it's probably a problem with the 1721's routing table. I'd suggest fixing it, since proxy-arp essentially allows broken networks to function as if they're not broken, which is generally bad.
This document gives several answers on frequently asked questions for PFRv3 channel state behavior.
Q1: What are all the channel operational states from a BR (border role) perspective and what are the rules/conditions to be in each st...
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