Nexus - spanning -tree port type ?

[ajay chauhan]

Hi Guys,

I need spanning tree port type details network/edge/normal. what comes as default and when to use other port type in network.

how would it behave when VPC is configured.

Switch A                        Switch B

Switch C  ------------------- Switch D

                   Switch E

Switch A is connected to C and D with trunk ports forming Port channel and L3 interface is configured on same Port channel.

Same way SwitchB is connected with C and D these port channel are part of VPC.

From Switch E which is Access switch forming VPC with C and D.

C and D are agg switches and all VPC config are on it .

C interface facing D is configured with port type network. C and D interfaces facing A and B (L3 device facing ) are port type edge trunk and interfaces n C and D facing E are simply set for default.

Need any doc for deep drive.

Thanks

Ajay

[Steve Fuller]

Hi Ajay,

It is recommended that switch-to-switch links are configured with the spanning-tree port type normalcommand. The one exception is the vPC peer-link which is recommended to configure with the spanning-tree port type network command.

Take a read of the Best Practices for Spanning Tree Protocol Interoperability from page 56 of the vPC Best Practice Design Guide for further information on this.

Regards

[Rodrigo Belo]

When changing the config from "spanning-tree port type network" to "spanning-tree port type normal", does the link go down/break?

I currently have 2 vPC domains connected with a vPC with Bridge Assurance enabled (STP port type network).

I want to change my config but I have to do it all remote and make sure that the link doesn`t break. If if does break, both firewalls will be active at the same tyme (diagram attached).

[bchintak]

I think spanning-tree port type network is the recommended practice for links connecting the cisco switches which support bridge assurance

[spoofneted]

...and finding out if Cisco Switches support Bridge Assurance or not is no easy feat. Pretty much every non-NX-OS Switch I've connected in doesn't.

For the time poor, do yourself a favour and turn it off with "spanning-tree port type normal".

I hate the arrogant naming of this syntax by Cisco - having a port type of "network" that only seems to work with a small proportion of Network Kit (seemingly no IOS) is a little bit misleading.

Just going to get in my "vehicle type car", which is actually only a very specific model of RC Tyco Car...

[Jeroen Huysmans]

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@spoofneted wrote:

...and finding out if Cisco Switches support Bridge Assurance or not is no easy feat. Pretty much every non-NX-OS Switch I've connected in doesn't.

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I respectfully disagree ;-) show spanning-tree summary can give you the answer...

below a screenshot from an IOS device, BA is supported in IOS starting 12.2(33)SXI if I'm not mistaken...

[abhisheksahas]

spanning-tree port type normal as well as spanning-tree port type network are used on ports connected to switches, the difference between them is:

normal: normal spanning-tree behaviour

network: Enablee spanning-tree with bridge assurance. If the opposite end does not support bridge assurance, it is recommended to configure spanning-tree port type normal, else the port / vlan(s) will be disabled.