symptom: devices on LAN cannot be pinged from the Cisco 800 series router. MAC addresses are there, as well as ARP entries. Interface counters show counters increasing for incoming traffic, but zero traffic outgoing. In the log continously the message %PQII_PRO_FE-4-QUEUE_FULL: Ethernet Switch Module transmit queue is full.
cause: in the LAN a loop was created and spanning tree was not active (interfaces configured with spanning-tree portfast).
solution: shutdown all LAN ports, except one. Have the LAN cabling checked.
