Link Aggregation – Disabling Spanning Tree Protocol

ciscoetherchannelpacket-tracerspanning treeswitch

It's a simple question, with switch interfaces using etherchannel,is necessary to use bpduguard in these interfaces for that disable Spanning-tree? Because using mode simulation of Packet Tracer, I can see STP Packet coming and going between the links.

Best Answer

Etherchannel has a way of fooling STP into thinking all the interfaces in a bundle are a single interface, and the etherchannel handles the STP, so you don't want to disable, or mess with, STP on etherchannels since it takes care of STP for you, and you risk creating loops if you change STP on an etherchannel. It is the same thing for an etherchannel bundle as it would be for any interface connecting to another switch: disabling STP can have very bad consequences.

Related Solutions

Switch – Brocade switches per vlan STP support

It's important to note that PVST/PVST+ is Cisco proprietary.

They do support one instance of STP per VLAN, and it is enabled by default. You can enable/disable STP on the following levels (taken from the NetIron config docs):

Globally - Affects all VLANs
Individual VLAN - Affects all ports within the specified VLAN. When you enable or disable STP within a VLAN, the setting overrides the global setting. Thus, you can enable STP for the ports within a VLAN even when STP is globally disabled, or disable the ports within a port-based VLAN when STP is globally enabled.
Individual Port - Affects only the individual port. However, if you change the STP state of the primary port in a LAG group, the change affects all ports in the LAG group.

Depending on your code rev, you can enter config mode for the VLAN and either do:

[no] spanning-tree

[no] rstp
[no] spanning-tree 802-1w (used on older versions of code)

I know that newer NetIron gear has PVST/PVST+ compatibility modes which you can turn on at the interface level with:

pvst-mode

But this also implies that you're going to be running MST, which you said you're not going to do.

Spanning Tree design considerations: MSTP and regions

Change the L2 links to L3 for the offices. ( Get help if needed)

This will prevent one of the uplinks to the offices blocking and provide double the bandwidth. (Assuming that there is a link from each DC the same size)
There is no chance of a spanning tree loop at a branch affecting the DC's
Broadcasts from any device on any site does not travel to all the ports on all the sites using the same vlan.
Traceroute will actually show the path packets are taking through your network.
If you do have problems with a spanning-tree loop, it will be localized to a single site.

Problem: Branch camera vlan protected by firewall

As vlan's will end at branch a new solution need to be implemented for the camera vlan, here is a couple of options

Small FW at each branch
ACL on Cam vlan only allowing cam IP's to talk to FW and subnet behind FW
More exotic options, GRE, MPLS, vrf-light