Troubleshooting guide
i
Contents
Preface .............................................................................................................................................. I
Safety Information .............................................................................................................. Safety-1
1. Overview ...................................................................................................................................... 1
1.1 Overview of analyzing failures ......................................................................................... 2
1.2 Overview of failure analysis for the entire Switch or a part of the Switch ........................ 3
1.3 Overview of functional failure analysis ............................................................................. 5
2. Troubleshooting Switch Failures .............................................................................................. 9
2.1 Procedure for handling switch faults ................................................................................. 10
3. Troubleshooting Functional Failures During Operation ......................................................... 13
3.1 Login-related problems ..................................................................................................... 14
3.1.1 Forgotten login password ..................................................................................... 14
3.1.2 Forgotten login user ID ........................................................................................ 14
3.1.3 Forgotten administrator mode password ............................................................. 14
3.2 Operation terminal problems ............................................................................................. 15
3.2.1 Information cannot be entered from the console or does not appear correctly ... 15
3.2.2 Login from a remote terminal is not possible ....................................................... 16
3.2.3 Login authentication using RADIUS is not possible ............................................ 17
3.2.4 Commands cannot be entered............................................................................. 18
3.3 Problems occurring while saving files ............................................................................... 19
3.3.1 Information cannot be saved in the startup configuration file .............................. 19
3.3.2 Copying or writing information to a memory card is not possible ........................ 19
3.3.3 Copying or writing information to the RAMDISK is not possible .......................... 20
3.3.4 Update by using the ppupdate operation command is not possible .................... 21
3.3.5 Restoring data by using the restore operation command is not possible ............ 21
3.3.6 Saving or restoring the binding database is not possible .................................... 23
3.4 Network interface communication failures ........................................................................ 24
3.4.1 Ethernet port cannot be connected ...................................................................... 24
3.4.2 Actions to be taken for 10BASE-T/100BASE-TX problems [AX1250S] [AX1240S]
............................................................................................................................ 25
3.4.3 Actions to be taken for 10BASE-T/100BASE-TX/1000BASE-T problems ........... 26
3.4.4 Actions to be taken for 100BASE-FX [AX1250S]/1000BASE-X problems .......... 27
3.4.5 Actions to be taken for PoE problems [AX2200S] [AX1240S] ............................. 29
3.4.6 Communication failures when link aggregation is used ....................................... 30
3.5 Layer 2 network communication failures ........................................................................... 32
3.5.1 Layer 2 communication by VLANs is not possible ............................................... 32
3.5.2 Failures occurring when the Spanning Tree functionality is used ........................ 34
3.5.3 Failures occurring when the Ring Protocol functionality is used ......................... 36
3.5.4 Failures when the DHCP snooping functionality is used ..................................... 37
3.5.5 Multicast forwarding by IGMP snooping is not possible ...................................... 42
3.5.6 Multicast forwarding by MLD snooping is not possible ........................................ 44
3.6 IPv4 network communication failures................................................................................ 47
3.6.1 Communication is not possible or is disconnected .............................................. 47
3.7 Layer 2 authentication communication failures ................................................................. 50
3.7.1 Communication failures occurring when IEEE 802.1X is used ............................ 50
3.7.2 Communication failures occurring when Web authentication is used ................. 54
3.7.3 Communication failures occurring when MAC-based authentication is used ...... 59
3.7.4 Communication failures occurring when secure Wake-on-LAN is used [OP-WOL]
............................................................................................................................ 63
3.8 Communication failures in the high-reliability functionality based on a redundant configuration
......................................................................................................................................... 66
3.8.1 Communication failures occurring when uplink redundancy is used ................... 66
3.9 SNMP communication failures .......................................................................................... 68
3.9.1 MIBs cannot be obtained from the SNMP manager ............................................ 68