193 Troubleshooting Functional Failuresin OperationThis chapter describes actions to be taken when the system does not operate normallyor the communication is not possible.3.1 Problems on Login Password3.2 Problems on MC3.3 Problems on Operation Terminal3.4 Network Interface Communication Failure3.5 Layer 2 Network Communication Failure3.6 IPv4 Network Communication Failure3.7 IPv4 Unicast Routing Communication Failure3.8 IPv4 Multicast Routing Communication Failure3.9 IPv6 Network Communication Failure3.10 IPv6 Unicast Routing Communication Failure3.11 IPv6 Multicast Routing Communication Failure3.12 Layer 2 Authentication Communication Failure3.13 Communication Failure on High-reliability Function3.14 SNMP Communication Failure3.15 Troubleshooting of sFlow Statistics (Flow Statistics) Function3.16 Communication Failures on Neighboring System Managing Function3.17 NTP Communication Failure3.18 Communication Failure on IEEE802.3ah/UDLD Function3.19 Problems on Redundant Configuration of Basic Control Unit (BCU)/Control and SwitchingUnit (CSU)/Management and Switching Unit (MSU) [IP8800/S6700] [IP8800/S6600][IP8800/S6300]