Article ID: 10798
Products
SecureStack C3, C2, B3, B2, A2; all firmware
Changes
Increased Spanning Tree logging to debug level: 'set logging application STP level 8'.
Symptoms
Warning messages are seen in Syslog and in the output of a 'show logging buffer' command, for example:<166>Jul 22 23:27:02 10.20.0.100-1 DOT1S[168229008]: dot1s_ih.c(1342) 157 %%
Setting Port(160) instance(0) State: DISCARDING
<166>Jul 22 23:27:02 10.20.0.100-1 DOT1S[168229008]: dot1s_ih.c(1264) 158 %%
Setting Port(160) instance(0) State: LEARNING
<166>Jul 22 23:27:02 10.20.0.100-1 DOT1S[168229008]: dot1s_ih.c(1303) 159 %%
Setting Port(160) instance(0) State: FORWARDING
Cause
These messages logged by the switch/stack manager unit record Spanning Tree state changes - generally the results of a Link up or Link down change.
Solution/Workaround
Functioned as Designed (FAD).
These messages are useful for debugging purposes only.
Specifically, note if a certain port is frequently reporting link state changes throughout the day, then compare its port settings - speed, duplex, and negotiation - to those of its peer (
4674). Also investigate other reasons why the port link may be cycling, and reasons why it otherwise may be seeing its view of the Spanning Tree changing.
The MIB2 Interface numbering convention used in the message may be translated as described in
12864, thereby computing the affected unit and port number.
For instance, the interface number "160" in this example translates to the 4th port of unit 4 (e.g. fe.4.4, ge.4.4).
