i have 3 vlans, vlan1 , vlan 10 and vlan 20 with vlan interface for intervlan routing and vtp configrued on my 4503-E switch because i have also two stacked 3750 switch in the network. i connect cisco 4503 switch with 3com 7700 switch using trunk ports. now the problem is that from 3com 7700 switch host are able to ping all 3 vlans but from cisco 4503 vlan 10 and vlan 20 are not able to ping host connected to 3com 7700 switch.