Preferred Placement of Root Bridge

Answered Question
Mar 9th, 2009
User Badges:

I'm running HSRP on H1 and H2, tracking the interfaces to the routers and between H1 & H2 Trunk link. I'm routing between R1, R2, H1 and H2's connections. I've been getting mixed reviews on the placement of the Root Bridge. I feel that the placement should be on H1 and the backup H2. Can someone help me on this concern.


Thanks,

Sal



Attachment: 
Correct Answer by Jon Marshall about 8 years 2 weeks ago

Sal


H4 - 10, what are these switches and do they have any resiliency ?


It's difficult to comment too much without knowing the layout, fibre runs etc. An also are all devices connected to the edge switches singly honed.


What i would look to do is either


1) remove H3 -> H10 and dual connect each edge switch to the pair of 6500's. You could still remove the 3750's in this scenario


OR


2) more likely as i suspect you need H3 -> H10 for port capacity, make sure you dual hone H3 -> H10 to both 6500 switches.


Jon

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
Jon Marshall Mon, 03/09/2009 - 08:04
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

Sal


You don't say what device the other switches are but there is nothing wrong in choosing H1 & H2. If they are responsible for inter-vlan routing it also makes sense to have them as STP root and secondary.


More importantly, what purpose does H3 server in your network as it is a single point of failure. Is it needed or could you connect your edge switches directly to the 3750's ?


It's not entirely clear from your diagram whether H4 & H5 are edge switches or whether the devices connected to H4 & H5 are edge switches so some of what i have said may not be applicable. Could you clarify ?


Jon

s.marino Mon, 03/09/2009 - 08:21
User Badges:

Jon,


H4 and H5 (There is also H6 - H10 but not shownwith many edge switches off of them) are other distribution switches in this campus design. The switches off of them are edge switches. H3 is a Cabletron 6000 with fiber blades that all other distribution points come back to at this time. The 3750's will be getting replaced in the next six months with two 6509's. Hope this helps!!!!

Jon Marshall Mon, 03/09/2009 - 08:34
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

So H4 - 10 are acting as L2 switches only ?


Jon

s.marino Mon, 03/09/2009 - 08:37
User Badges:

Jon,


Yes H3, H4 - 10 they are acting as L2 switches.

Jon Marshall Mon, 03/09/2009 - 08:40
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

Okay, then i would use H1 & H2 as long as they are not overloaded. The root and secondary bride placement are generally tied to the core/distro of your switches. You don't really have a distro layer rather an extended access layer with the distro layer in effect being the 3750's.


Jon

s.marino Mon, 03/09/2009 - 09:21
User Badges:

Okay, so when I install the two 6509's in place of the 3750's and removed H3 from production, will I have an ideal design with this campus. The 6509's will act as the core/distro for all the switches in the campus?


Thanks,


Sal

Correct Answer
Jon Marshall Mon, 03/09/2009 - 09:29
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

Sal


H4 - 10, what are these switches and do they have any resiliency ?


It's difficult to comment too much without knowing the layout, fibre runs etc. An also are all devices connected to the edge switches singly honed.


What i would look to do is either


1) remove H3 -> H10 and dual connect each edge switch to the pair of 6500's. You could still remove the 3750's in this scenario


OR


2) more likely as i suspect you need H3 -> H10 for port capacity, make sure you dual hone H3 -> H10 to both 6500 switches.


Jon

s.marino Mon, 03/09/2009 - 09:41
User Badges:

Jon,


Option 2 looks to being what I will need to accomplish. Thanks Jon for all of your time and input!!!

Jon Marshall Mon, 03/09/2009 - 09:42
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

No problem. glad to have been of help.

Actions

This Discussion