Hi Everybody, I ran into a weird trouble the yesterday.. I am having a Cisco 3600 router with some 16 Class-C connected to the Fast Ethernet as secondary addresses. My host were not able to ping the router across the ethernet at all... I was seeing the ARP entry of my host on the router but not able to ping the host from the router and vice-versa across the ethernet......when i cleared the arp-cache everything is working...( Not sure when the trouble may come back!!!!) Can somebody tell 1) What is the size of the ARP-CACHE, where i can see it and how i can manipulate it. 2) If i have "n" hosts and "n" is the maximum hosts the Arp-cache can accomidate when "n+1" host try to get to a host it will send a brodcast and get the MAC and get itself into the ARP-Cache removing the oldest entry in the ARP right????? Apparently this does NOT seem to be happening...... Is my understanding wrong ???? or is this a weird cisco IOS stuff!!!!! which needs the regular upgrade???? Any help is greatly appreciated. Thanks Satish Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=12270&t=12270 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]