Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

spanning-tree portfast on a switchport to another switch

Posted on 2010-09-09
3
Medium Priority
?
746 Views
Last Modified: 2012-05-10
We have a simple network. Locally, we have 4 2950's behind a 2611. We
have about 60 PCs. We have instances where an inexpensive 4-port DLINK switch (something
meant for a personal PC or a small office) joins 2 - 4 PCs to a single switchport on a
2950 switch. On the Cisco config of these switchports, we have entered "no spanning-tree
portfast."

We often move PCs. When we do, the location of the DLINK switches sometimes change,
requiring us to change the config on the relative Cisco switchports. My question: Is there
any real danger in having a small 4-port DLINK switch with 2 - 4 PCs plugged into a Cisco
switchport with spanning-tree portfast enabled?
0
Comment
Question by:meade470
3 Comments
 
LVL 3

Accepted Solution

by:
kf4zmt earned 1000 total points
ID: 33640238
No danger as long as the dlink ONLY connects to one switch port.  The danger comes in when the dlink connects to multiple switches/hubs where a loop could be created.  If you are certain the dlink only connects to one switch and to only one port on that switch you can safely enable portfast.
0
 
LVL 50

Assisted Solution

by:Don Johnston
Don Johnston earned 1000 total points
ID: 33642181
>Is there any real danger in having a small 4-port DLINK switch with 2 - 4 PCs plugged into a Cisco
switchport with spanning-tree portfast enabled?

No. Then again, there's not much to gain either. The big advantage to portfast is that the port can forward traffic as soon as a link is detected (instead of going through the 30 second listening/learning delay). But with a switch connected to the port, the link will always be up so portfast isn't going to make any difference.

If it were me, I'd leave portfast off on those ports.



0
 
LVL 2

Author Closing Comment

by:meade470
ID: 33646300
Thanks, guys. I agree with both ideas and will have to make a decision.
0

Featured Post

Ask an Anonymous Question!

Don't feel intimidated by what you don't know. Ask your question anonymously. It's easy! Learn more and upgrade.

Question has a verified solution.

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

When you try to share a printer , you may receive one of the following error messages. Error message when you use the Add Printer Wizard to share a printer: Windows could not share your printer. Operation could not be completed (Error 0x000006…
If you’re involved with your company’s wide area network (WAN), you’ve probably heard about SD-WANs. They’re the “boy wonder” of networking, ostensibly allowing companies to replace expensive MPLS lines with low-cost Internet access. But, are they …
Viewers will learn how to connect to a wireless network using the network security key. They will also learn how to access the IP address and DNS server for connections that must be done manually. After setting up a router, find the network security…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

971 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