Failures On Using Spanning Tree - NEC IP8800/S2400 Series Troubleshooting Manual

3.
Troubleshooting Functional Failures in Operation
[When Type displayed is Dot1x]
See "3.12.1 Communication Failure on Using IEEE
[When Type displayed is Wa]
See "3.12.2 Communication Failure on Using Web
[When Type displayed is Macauth]
See "3.12.3 Communication Failure on Using MAC
• Flooding is executed if the MAC address is not displayed.
• IP8800/S6700, IP8800/S6600, and IP8800/S6300:
If the communication still has been blocked despite no display appears, check to see if learning is suspended by
MAC address learning limitation. In addition, check to see if the threshold in the Storm Control function is not too
low.
• IP8800/S3600 and IP8800/S2400:
If the communication still has been blocked despite no display appears, check to see if the Suppress Port-to-Port
Forwarding has been enabled. In addition, check to see if the threshold in the Storm Control function is not too low.
(b) Checking MAC address learning limitation [IP8800/S6700] [IP8800/S6600] [IP8800/S6300]
Execute the show mac-address-table command with "learning-counter" parameter specified to check the
information of MAC address learning limitation for the port and the VLAN to be checked.
>show mac-address-table learning-counter port 1/1-6
Date 2005/09/21 20:00:57 UTC
Port counts:6
Port Count
1/1
1/2 1000
1/3
1/4
1/5
1/6
>show mac-address-table learning-counter vlan
Date 2005/09/21 20:00:57 UTC
VLAN counts:4
ID Count
1
100 1000
200
4095
1. MAC address learning is suspended according to the MAC address learning limitation value. Frames from the
unlearned source address are discarded without learning the MAC address. However, flooding is executed for frames
of VLAN for which MAC address learning is suppressed.
2. Suppression of MAC address learning is set. Flooding is executed for received frames.
(4) Checking filtering/QoS
Certain packets may have been discarded by filtering, or packets may have been discarded through bandwidth
monitoring, discarding control, or shaper of the QoS control. Check to see if the conditions of filtering and QoS control
in the configuration have been set up correctly and if bandwidth monitoring, discarding control, or shaper has been set
up appropriately for system operation. For the procedure, see
3.5.2

Failures on Using Spanning Tree

If the spanning tree function is in use and a layer 2 communication failure occurs or the spanning tree operation status
does not comply with the network configuration, isolate the problem according to the analysis method listed below. For
the multiple spanning trees, check for each CIST or MST instance. For example, read the CIST route bridge or the route
40
Maximum Threshold
3 -
1000 800
0 -
50 60 40
45 60 40
0 60 40
Maximum Threshold
3 -
1000 800
0 -
90 100 100
802.1X."
Authentication."
Authentication."
Status
- -
Learning
- -
Stop learning <---1
Learning
Learning
Status
- -
Stop learning <---1
- No learning <---2
Learning
3.23.1 Checking Filtering/QoS Setting Information
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