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Core and Distribution 802.1Q

SteveNode03
Level 1
Level 1

Hi -

 

What is the best method to configure an Access switch with two fiber SFPs?

I configured two Distribution cores running HSRP.  I want to follow the best practice to configure the trunks.  Essentially the Access switch is going to connect to the Active HSRP and the second link to the standby HSRP. 

 

thanks

Steve

1 Accepted Solution

Accepted Solutions

awesome.  I think at the time the LC connectors were dirty creating a lot of CRCs.  I just wanted to make sure. thank you

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7 Replies 7

Richard Burts
Hall of Fame
Hall of Fame

Steve

 

Perhaps there are aspects of your question that I am not understanding. And if so then please clarify. It seems fairly straightforward (as least the way that I understand your question). If you have an access switch with 2 SFP and you have 2 distribution/core switches then you need each access switch port with an SFP to connect to one of the distribution/core switches.  If there is more than one vlan present on the access switch then the connection from access to distribution/core should be a trunk. Which connection will be utilized will depend on the operation of HSRP on the distribution/core switches. Is there something else you are looking for?

 

HTH

 

Rick

HTH

Rick

Here is my topology. I am revisiting these configurations on the network, so I wanted to make sure that the simple interface configuration is just an 802.1Q or does it need something configured for it to be redundant. 

 

Spanning Tree shouldn't shutdown the secondary port thinking it is creating a loop on the Layer 2 network right?

 

HSRP.jpg

 

If the interconnects between your distribution switches are L2 trunks then yes STP will block one of the uplinks from your access switch which is exactly what you want otherwise you have a loop. 

 

Note if you are running a per vlan STP version it will block per vlan so you can use both uplinks but only uplink per vlan. 

 

If the interconnects are L3 then no it won't block as long as you do not have the vlans on the access switch on other access switches. 

 

Jon

Thanks Jon.  I am ok with the blocking, which I understand. A while back when I uplinking the SFP trunks on the network I think the secondary link would shutdown, but it could have been from a dirty LC connector.  At the moment I am testing the secondary fiber pairs and documenting the topology.  I am planning ahead to uplink a secondary link in case a fiber pair fails.  I just dont want the Core to shutdown the secondary L2 port that is on the standby core for the access switch.  I need that one to stay connected and the secondary on standby to eliminate the single point of failure.

 

Many thanks

Steve

 

STP should not shut the port down, it should just block unless you have something configured incorrectly. 

 

Jon

awesome.  I think at the time the LC connectors were dirty creating a lot of CRCs.  I just wanted to make sure. thank you

yep they were dirty LC to LC connectors.  Both trunks are working fine. thanks

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