spanning tree and ether channle configuration.

[mauleshg1]

Hi,

we are having 3850 at core which is installed in stacking.

we are having 4500-x at distribution level which is installed in VSS.

we are having 2960-x at access level which is installed in stack and stand alone also.

all switch is connected through fiber or copper uplink. 90% Fiber uplink.

Please find attached logical architecture and help me.

we required help for spanning tree best practices configuration.

1.  which switch should be root bridge.

2. what best practices we should apply for spanning tree.

3. what is udld and should we configure udld.

4. what configuration required to avoid physical loop in same switch.

We required help for ether-channel configuration.

1. Which protocol should we configure PAGP or LACP.

2. which load balance method should we configure.

[Deepak Kumar]

Hi,

Q 1: which switch should be root bridge?

Ans: Distribution Switch (4500-x).

Q2: what best practices we should apply for spanning tree?

Ans:  Read an article

https://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/10556-16.html

Q3" what is udld and should we configure udld?

Ans: UDLD is a Layer 2 (L2) protocol that works with the Layer 1 (L1) mechanisms to determine the physical status of a link. At Layer 1, auto-negotiation takes care of physical signalling and fault detection. UDLD performs tasks that auto-negotiation cannot perform, such as detecting the identities of neighbours and shutting down misconnected ports. When you enable both auto-negotiation and UDLD, Layer 1 and Layer 2 detections work together to prevent physical and logical unidirectional connections and the malfunctioning of other protocols.

UDLD works by exchanging protocol packets between the neighbouring devices. In order for UDLD to work, both devices on the link must support UDLD and have it enabled on respective ports

UDLD can also be just as useful on copper links traversing intermediate "dumb" devices, such as media converters.

http://packetlife.net/blog/2011/mar/7/udld/

Q 4: what configuration required to avoid physical loop in same switch?

Ans: Spanning tree Root guard, Spanning tree Backbone fast, uplinkfast, UDLD etc. (as per your network topology diagram).

Q5: Which protocol should we configure PAGP or LACP?

Ans: LACP.

Q6: which load balance method should we configure?

Ans: It depends on your network topology and traffic type. Basic Idea is Access layer to distribution layer as Source MAC address & destination Mac address and from Distribution layer to Core layer as source IP & destination IP (If a routing protocol is running between Distribution and Core).

Regards,

Deepak Kumar