Switch Flapping

Hey all i have 2 switches which are both onnected to a router, and the router is configured with bridging to provide redundancy.  Now the problem is, when i 'no shut' both ports on the router connected to the switches, it all works well for 20secs and i can even ping succesfully, but then is comes up saying that the po1 port is flapping with port such and such and then both ports goto into err-disabled mode. I was wondering how i get around that??  Or is there another way to try and get 2 ports on the same router to be able to use the same default-gateway.

Cheers
Thunder-CatAsked:
Who is Participating?
 
Thunder-CatConnect With a Mentor Author Commented:
I figured it out i ended up taking port-channelling off the switchports going to the router and it stopped flapping.
0
 
from_expConnect With a Mentor Commented:
possibly you have created a loop within your network.
do you have spanning tree enabled?
what is your network topology?
0
 
Thunder-CatAuthor Commented:
hey thanks for the reply, the topo is a c7000 connected to a router via two switches in parallel for redundancy and the trunk ports from the switches to the router have spanning-tree portfast trunk enabled.  when i type "sh bridge" on the router no mac addresses appear.
0
The new generation of project management tools

With monday.com’s project management tool, you can see what everyone on your team is working in a single glance. Its intuitive dashboards are customizable, so you can create systems that work for you.

 
Aaron StreetConnect With a Mentor Infrastructure ManagerCommented:
you dont want port fast!!!

that shoudl only ever be used on access ports to connect host devices to!!

never switch to switch ports!
0
 
from_expConnect With a Mentor Commented:
hmmm, spanning tree port fast should be disabled on non-end ports....
if c7000 is hp blade chassis, then what kind of network modules do you have?
0
 
Aaron StreetConnect With a Mentor Infrastructure ManagerCommented:
ps see your other question.

0
All Courses

From novice to tech pro — start learning today.