Static Route to EIGRP

Answered Question
Mar 7th, 2008
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I have been asked to change a totally static route network with multiple vlans and layer3 switching to an EIGRP network. My director was told that we need to either run STP or Routing protocol but not both. I thought that we should run both. PLease give your thoughts. Thanks.

Correct Answer by lamav about 9 years 2 months ago

Jim:


I'm not sure what your management is thinking, but STP and EIGRP perform 2 totally separate and unrelated tasks.


EIGRP is a routing protocol that routes IP, IPX or Apple Talk (Layer 3) traffic which allows a router to advertise network reachability to its neighbors. It would replace your current static route methodology with a dynamic and much more scalable system.


Spanning Tree Protocol (STP) is an algorithm used to prevent Layer 2 switching loops by blocking redundant L2 links from passing user traffic. In the event of a link failure, the redundant L2 link will go through the STP port state migration process until it is changed to the 'forwarding' state and begins passing traffic.


Routing advertisements, updates and queries are passed over L3 routed links, not layer 2 switched links, while STP Bridge Protocol Data Units (BPDUs) travel over L2 links, not layer 3 links, so I don't understand why they are imposing an either/or proposition.


I hope I have been able to shed some light.


If so, kindly rate this post.


Victor

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Correct Answer
lamav Fri, 03/07/2008 - 07:53
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Jim:


I'm not sure what your management is thinking, but STP and EIGRP perform 2 totally separate and unrelated tasks.


EIGRP is a routing protocol that routes IP, IPX or Apple Talk (Layer 3) traffic which allows a router to advertise network reachability to its neighbors. It would replace your current static route methodology with a dynamic and much more scalable system.


Spanning Tree Protocol (STP) is an algorithm used to prevent Layer 2 switching loops by blocking redundant L2 links from passing user traffic. In the event of a link failure, the redundant L2 link will go through the STP port state migration process until it is changed to the 'forwarding' state and begins passing traffic.


Routing advertisements, updates and queries are passed over L3 routed links, not layer 2 switched links, while STP Bridge Protocol Data Units (BPDUs) travel over L2 links, not layer 3 links, so I don't understand why they are imposing an either/or proposition.


I hope I have been able to shed some light.


If so, kindly rate this post.


Victor

JIM COURTNEY Fri, 03/07/2008 - 09:00
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Victor,


This is exactly what I told them. I reminded them that we are talking about two totally different layers here. So in short you basically you helped greatly.


Thanks so much!

lamav Fri, 03/07/2008 - 12:32
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Jim:


Glad to know I could help you. Please feel free to post here anytime.


Victor

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