There are a total of 79 devices in the ring, all supporting RSTP.
All port costs are the same, all segment speeds are the same.
My assumptions -
When the network starts up, the the bridge with priority 0 will be elected as root.
At all the switches which are upto 39 hop counts away from the root in each direction in the ring, the received BPDUs are still valid (Message age < Max Age) . Hence the port on the 39th switch with the higher MAC ID than it's neighbor will have the 'Alternate' role. With this an ethernet loop is prevented.
Will the network converge as described in point 2 above or is my assumption flawed?
Only if it is valid, consider the second scenario - suppose there is a link failure between the 2nd and 3rd switch from the root bridge in one direction. Now instead of a ring, we have a long daisy chain of 79 switches. There will be 2 switches at one side of the root switch, and 76 switches on the other side. At the switch at a hop count of 40 from the root bridge, the BPDUs will be discarded, since the Message Age will be equal to the Max Age.
Is there a chance of a stable network convergence in this network?
What happens to the switches #40 to #76 and their ports? Switch #41 will not see the BPDUs indicating the root bridge with priority 0. So it will send BPDUs in both directions with Max Age set to 40. How will switch #40 and #39 react to these BPDUs?
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Cisco’s software-defined wide area network (SD-WAN) solution allows user to quickly and seamlessly establish an overlay fabric to connect an enterprise’s data centers, branch and campus locations, as well as colocation facilities in order to imp...
1. Log into CLI of DNAC:
ssh maglev@< DNAC appliance IP> -p 2222
2. Run this curl command to get token to get member id:
curl -X POST -u admin:<admin user password> -H -V https://<CLUSTER-IP>/api/system/v1/identitymgmt/token
Enterprise Switching Business Unit is glad to announce Beta release 16.12.2 for all Catalyst 9200/9300/9400/9500/9600 and Catalyst 3650/3850 Platforms. This release is made available to allow users to test, evaluate and share fee...
Purpose of the document
This document describes the general recommendations or best practices when designing and deploying the Cisco SD-Access technology. The document assumes that the reader has a general overview of Cisco's SD-Access for Distributed C...