Troubleshooting

Unusual Network Activity

it either must match the server key or you must configure a server-specific key. If the switch already has a server-specific key assigned to the server’s IP address, then it overrides the global key and must match the server key.

Global RADIUS Encryption Key

Unique RADIUS Encryption Key for the RADIUS server at 10.33.18.119

 

Figure C-4. Examples of Global and Unique Encryption Keys

 

Spanning-Tree Protocol (STP) and Fast-Uplink

 

Problems

 

 

C a u t i o n

If you enable STP, it is recommended that you leave the remainder of the STP

 

parameter settings at their default values until you have had an opportunity

 

to evaluate STP performance in your network. Because incorrect STP settings

 

can adversely affect network performance, you should avoid making changes

 

without having a strong understanding of how STP operates. To learn the

 

details of STP operation, refer to the IEEE 802.1D standard.

 

Broadcast Storms Appearing in the Network. This can occur when

 

 

there are physical loops (redundant links) in the topology.Where this exists,

 

you should enable STP on all bridging devices in the topology in order for the

 

loop to be detected.

 

STP Blocks a Link in a VLAN Even Though There Are No Redundant

 

Links in that VLAN. In 802.1Q-compliant devices such as the switches cov­

 

ered by this guide, STP blocks redundant physical links even if they are in

 

separate VLANs. A solution is to use only one, multiple-VLAN (tagged) link

 

between the devices. Also, if ports are available, you can improve the band-

 

width in this situation by using a port trunk. See the chapter on VLANs in the

 

Advanced Traffic Management Guide..

C-15