One server "storage" gets a bad arp entry in the local arp cache for all users on the network and therefore users cannot connect . Once I delete the arp entry locally on a client pc for "storage" , then receive the correct ip to mac entry it works . The "bad mac" entry for storage appears to be the cisco pix, I cleared the arp cache there as it did have a bad entry for "storage" . The pix arp cache is correct, however, users still receive a bad arp entry for "storage" , again, it is the cisco pix mac address. So again , have to use arp -d and the storage ip to get it to work again .