Solved

Switch Flapping

Posted on 2008-10-28
6
1,791 Views
Last Modified: 2009-01-10
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
0
Comment
Question by:Thunder-Cat
  • 2
  • 2
  • 2
6 Comments
 
LVL 21

Assisted Solution

by:from_exp
from_exp earned 200 total points
ID: 22819716
possibly you have created a loop within your network.
do you have spanning tree enabled?
what is your network topology?
0
 

Author Comment

by:Thunder-Cat
ID: 22820273
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
 
LVL 16

Assisted Solution

by:Aaron Street
Aaron Street earned 200 total points
ID: 22820425
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
Zoho SalesIQ

Hassle-free live chat software re-imagined for business growth. 2 users, always free.

 
LVL 21

Assisted Solution

by:from_exp
from_exp earned 200 total points
ID: 22820439
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
 
LVL 16

Assisted Solution

by:Aaron Street
Aaron Street earned 200 total points
ID: 22820444
ps see your other question.

0
 

Accepted Solution

by:
Thunder-Cat earned 0 total points
ID: 23294068
I figured it out i ended up taking port-channelling off the switchports going to the router and it stopped flapping.
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

We've been using the Cisco/Linksys RV042 for years as: - an internet Gateway - a site-to-site VPN device - a leased line site-to-site subnet-to-subnet interface (And, here I'm assuming that any RV0xx behaves the same way as an RV042.  So that's …
Tired of waiting for your show or movie to load?  Are buffering issues a constant problem with your internet connection?  Check this article out to see if these simple adjustments are the solution for you.
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

920 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

18 Experts available now in Live!

Get 1:1 Help Now