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Default features in 6500 series switches

Hello,

some of the features of 6500 are enabled by default and woudn't appear in the "Show run".  See the command below and how do I make sure whether these featues are enabled by default or not.  Would it appear in the config if enabled?

ip verify unicast source reachable-via rx

ip verify unicast source reachable-via any

storm-control broadcast level 70

-------------------------------------------------------------------------------

what are the difference between the commands below and can they be enabled together.

spanning-tree guard root

vs

spanning-tree loopguard default

vs

spanning-tree guard loop

1 ACCEPTED SOLUTION

Accepted Solutions

Re: Default features in 6500 series switches

You can do "show run all" to see all of the defaults, and no, defaults usually don't show up in the running config.

Spanning-tree guard root enables root guard on a port. It protects the root of the spanning-tree.

Loopguard default enables loopguard on all ports that are point-to-point. (Connected to another switch)

Spanning-tree guard loop overrides loopguard default and it also keeps a port from going into forwarding if it stops hearing bpdus.

You can use all of them on the same switch because they 2 do different things. Root guard protects the root switch. Say that you have a root switch. If you connect another switch that supports STP and it has a lower bridge ID than the current root, the topology will change when you connect the switch to port 2. If you had root guard configured on port 2, the port goes into a root-inconsistent state and doesn't forward on the port. Root-inconsistent will automatically recover once it stops hearing the superior bpdus.

Loopguard keeps a blocking port from going into forwarding when it stops receiving bpdus on the blocked port. It puts the port in loop-inconsistent. The loopguard will automatically reenable the port once it hears bpdus again. It reenables the port back into the blocking state.

Spanning-tree guard loop is the same thing as above, but it's put directly on the interface.

*Edit* Storm control isn't enabled by default, and I'm pretty sure that uRPF isn't either.

HTH,

John

Please rate useful posts...

HTH, John *** Please rate all useful posts ***
1 REPLY

Re: Default features in 6500 series switches

You can do "show run all" to see all of the defaults, and no, defaults usually don't show up in the running config.

Spanning-tree guard root enables root guard on a port. It protects the root of the spanning-tree.

Loopguard default enables loopguard on all ports that are point-to-point. (Connected to another switch)

Spanning-tree guard loop overrides loopguard default and it also keeps a port from going into forwarding if it stops hearing bpdus.

You can use all of them on the same switch because they 2 do different things. Root guard protects the root switch. Say that you have a root switch. If you connect another switch that supports STP and it has a lower bridge ID than the current root, the topology will change when you connect the switch to port 2. If you had root guard configured on port 2, the port goes into a root-inconsistent state and doesn't forward on the port. Root-inconsistent will automatically recover once it stops hearing the superior bpdus.

Loopguard keeps a blocking port from going into forwarding when it stops receiving bpdus on the blocked port. It puts the port in loop-inconsistent. The loopguard will automatically reenable the port once it hears bpdus again. It reenables the port back into the blocking state.

Spanning-tree guard loop is the same thing as above, but it's put directly on the interface.

*Edit* Storm control isn't enabled by default, and I'm pretty sure that uRPF isn't either.

HTH,

John

Please rate useful posts...

HTH, John *** Please rate all useful posts ***
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