Hi, I have a problem very similar to the one described on "problem with vlan + arp" posted on this newsgroup on Sept , 2009 but I can't understand the answer so I kindly ask your help: let's consider the scenario described in that post: if the arp timeout in the router is lower than the mac address timeout in the mac forwarding table in the switch there should be no problem because the router will arp the dest_IP_addr and the switch will just refresh the mac forw table when the destination host will reply to the arp, right?? But (here is what I probably didn't undestand) in my opinion if the arp timeout in the router is higher than the mac addr timeout in the switch, the router will send a unicast frame (bacause he know the correct dest_mac_adress) and the switch will forward that frame on every port exept the source port of the frame (as far as I know the switches do this when they don-t know where a mac address is), if this is correct there should be no ping timeout neither is the first nor in the second scenario; so i can't imagine a scenario in wich this "timeout mismatch" could be a problem....but in my networdk I have the same problem and I solve it clearing the arp-cache on the router :-). Would someone please clarify me when the timeout mismatch can cause a problem? Thank you very much for reading. Gabriele
- posted
14 years ago