[Okta Webinar] Learn how to a build a cloud-first strategyRegister Now

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 883
  • Last Modified:

Link aggregation and Spanning Tree on ALCATEL 7800 switches

Hi, heres the set up....

im bench testing 2 Alcatel 7800 Switches, the current config copied from 2 existing Switches.
the current switches use Spanning Tree using 2 fibre ports, one port blocking, the other forwarding.

on the bench i've added to the current configuration an aggregated link using gigabit Ethernet.

now I have 2 active conections conecting the switches.

 - 1 Gigabit Fibre link forwarding (with another blocking Span Tree)
 - 1 Aggregated link gigabit ethernet.

now i'm sure this is a Loop in the network between the 2 switches?? am I right?

if so why doesnt the spanning tree doesnt block the forwarding conection??
0
bluebirds1984
Asked:
bluebirds1984
  • 3
  • 3
1 Solution
 
harbor235Commented:
What do you mean one aggregated link? Do you mean your running something like Gigchannel? Where you have two
physical links acting as one virtual link? If so then the aggregated link(s) are acting as one virtual link and spanning tree sees that as just one link. Please clarify.

harbor235
0
 
pseudocyberCommented:
Could be that spanning tree isn't running on your aggregated links.  Or they're in a different Spanning Tree group.  Yes, the way you described it, there should be a loop condition existing.
0
 
bluebirds1984Author Commented:
SWITCH 1                                                           SWITCH 2

GIGABIT FIBRE -----------------------------------------GIGABIT FIBRE>>>| - FORWARDING
                                                                                                            SPANNING TREE CONFIG
GIGABIT FIBRE------------------------------------------GIGABIT FIBRE>>>| - BLOCKING


GIGABIT ETHERNET------------------------------------GIGABIT ETHERNET>>>|
                                                                                                                AGGREGATED LINK CONFIG - UP
GIGABIT ETHERNET------------------------------------GIGABIT ETHERNET>>>|


hopefully the above explains it a bit more clearly

there are 2 active conections between the switches, causing a loop.
Forgetting about the pro's or cons between Fibre or Ethernet, id like to know peoples thoughts on why the Spanning tree fibre isn't blocking?


pseudocyber - what do you mean when you say Spanning Tree Group? i wish we used Cisco instead of Alcatel, nobody uses Alcatel!
0
Microsoft Certification Exam 74-409

VeeamĀ® is happy to provide the Microsoft community with a study guide prepared by MVP and MCT, Orin Thomas. This guide will take you through each of the exam objectives, helping you to prepare for and pass the examination.

 
pseudocyberCommented:
You can have different spanning tree groups.  If the ports in the fiber are in group 1, and the ports in copper are in group 2, they could both be forwarding without seeing a loop.

On the other hand, perhaps your spanning tree isn't working right?
0
 
bluebirds1984Author Commented:
yeah i see what you mean.

i have one spanning tree group and one link aggregation group. from what I've read the link agg group needs to be included in the Spanning Tree group, but not as the individual ports but as the Virtual port thats assigned to it.

i'll test it out when I get the opportunity and post the results.
0
 
bluebirds1984Author Commented:
I added the virtual link agg port to the spanning tree group and it worked perfectly.

thanks
0
 
pseudocyberCommented:
Thanks. :)
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

  • 3
  • 3
Tackle projects and never again get stuck behind a technical roadblock.
Join Now