Adjusting the MaxAge Timer on a Set/Clear Command−Based
IOS
To change the default MaxAge timer for a particular VLAN, use this Privileged mode command :
spantree maxage <time value> <VLAN>
In the following example, 5 refers to the MaxAge time and 1 refers to the VLAN:
spantree maxage 5 1
Preparing to Enable EtherChannel
When preparing to enable EtherChannel, you should check four items before configuring an EtherChannel
bundle. They are as follows:
If a bundle uses trunked ports, each port must be configured with the same allowed VLAN range. If
the VLAN ranges are not configured identically for both ends of all the trunked links in the bundle,
the data traffic for the particular missing VLAN traffic is not allowed and the frames for that VLAN
are dropped.
•
Trunked ports will not form a channel when set to the auto or desirable mode using the set port
channel command. However, trunked ports on which VLANs are allowed will continue to transmit
data traffic across their trunk links.
•
You must verify that port security is disabled on all channeled ports. By enabling port security, the
port shuts down when it receives packets containing a source address that doesn’t match the secure
address of the port.
•
All ports in a channel must be enabled. Any disabled ports are considered link failures by the switch,
and traffic for those ports is automatically transferred to any remaining ports in the bundle.
•
If these criteria are not met, then you will receive an error for each item that is not configured correctly when
you try to configure EtherChannel.
Viewing the Port Setting for EtherChannel on a Set/Clear
Command−Based Switch
To view the port settings on ports you are configuring for EtherChannel on a Set/Clear command−based
switch, use the following command in Privileged mode. Use this command to compare the settings to make
sure they match the other ports waiting to be configured as a bundle:
show port capabilities <module number/port number>
For this example, 2 is the module number and 1 is the port number. The output shows that the port is already
configured to participate in a bundle:
catalyst5000> (enable) show port capabilities 2/1
Model WS−X5225R
Port 2/1
Type 10/100BaseTX
Speed auto,10,100
Duplex half,full
Trunk encap type 802.1Q,ISL
Trunk mode on,off,desirable,auto,nonegotiate
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