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Topology questions for dual 5820 and dual 2910 switches

 
abc0a
Occasional Contributor

Topology questions for dual 5820 and dual 2910 switches

Hi

I was wondering if I could get some advice here regarding best topology setup based on following scenario:
We recently purchased two 5820AF-24XG (JG219A) and two 2910al-24G (J9145A) switches to support our new VMware cluster environment.
The VMware cluster consists of:

  •   - 1 management server (DL 360p G8) with 2 quad 1 Gbps NICs
  •   - 3 host servers (DL 380p G8) with 2 dual port 10 GBps NICS and 2 quad port 1 Gbps NICs
  •   - 1 3PAR 7200 storage server with 2 dual port 10 GBps NICS (iSCSI)


The networking setup (*at this time*) is following:

  •   - all 4 switches are independent
  •   - 5820s have 3 VLANs (management, iSCSI traffic to 3PAR storage, VM-2-VM traffic)
  •   - 2910s have 2 VLANs (management, vMotion traffic)
  •   - for each VLAN, each server contributes 2 NIC ports (on different NICs) which are then connected to separate switches
  •   - 5820s have 2 1 Gbps ports (ports 25,26) which we used as uplinks to 2910s for management purposes




Questions:

  1.   Our line of thinking was to keep switches independed (no interconnects on 2910s, no clustering on 5820s) so we can achieve redundancy and high availability. Is this the right approach? What would we gain/lose if we do interconnect them?
  2.   If we should interconnect them, what approach should we use for 5820s? AFAIK, there are no expansion modules to use (like with 2910s)...Clustering?
  3.  We need to "pass in" external traffic comming from 2910s to 5820s "VM-2-VM" VLAN. Since 1 Gbps uplinks are used for management, we were thinking of using dual port 10Gbps expansion module (J9908A) on 2910s with direct SFP+ cables. Then we would route this extanet VLAN to "VM-2-VM" VLAN at the switch level...Is this a good idea?

 

5 REPLIES
Vince_Whirlwind
Trusted Contributor

Re: Topology questions for dual 5820 and dual 2910 switches

1. "Interconnection" may or may not help - that would depend on your design, the thing that helps is switch "stacking", which allows you to create aggregated links across both switches (so you have active/active link pairs).

 

2. The 5820s should be IRFed. That "stacks" them properly. The 2910s don't support any kind of "stacking".

 

3. Not sure I understand. If you need 10Gb connectivity, just patch into the 5800s, right? Where is the "external traffic" coming from, physically? If it originates on the 2910s, then it's coming in on a 1Gb link, isn't it?

abc0a
Occasional Contributor

Re: Topology questions for dual 5820 and dual 2910 switches

Thanks for your reply VInce

 

Further comments:

 

Overall, I think I may be misunderstanding nuances between "interconnecting", "stacking", and "clustering".

I see those as the same term, and I may be wrong...

 

  1. I thought 2910's can be stacked by connecting them via module on the back of the switch. 2910s have 2 expansion module slots. We were thinking of using one slot to connect (J9165A) them toghether and the other slot for 2-port 10GB SFP+ module (J9008A) to connect them to 5800 switches...
  2. Are there any benefits to them not being IRFed?
  3. External traffic is comming from our firewall/router into 2910s and needs to be available on VM traffic VLAN which now only exists on 5820s. So yes, 2910s need to be connected to 5820s and we are looking at the best way to do so. Right now both 1Gbps ports on 5280s are being used by management VLANs so we can't use those. The question was could we (should we) use 2 port 10 GBs modules on 2910s (see #1 to connect to 5820) or some other method?

Thanks

Pete W
Valued Contributor

Re: Topology questions for dual 5820 and dual 2910 switches

> I thought 2910's can be stacked by connecting them via module on the back of the switch.

 

The general consensus of opionion is that "real" stacking is forming a logical switch from multiple individual switches. The new logical switch will have a single running config, can be managed with a single IP address, and (the acid test) can handle cross switch LACP aggregation.

 

The 2910al does not therefore form a stack, it simply has optional 10GbE interfaces that are useful for interconnecting switches.

 

> Are there any benefits to them not being IRFed?

Not many. IRF is fairly simple to configure, and gives you plenty of advantages.

 

The question was could we (should we) use 2 port 10 GBs modules on 2910s or some other method?

Use whatever gives you adequate bandwidth and appropriate resiliancy.

 

Regards,

 

Pete

 

 

HPE MASE
Aruba ACMP
Fortinet NSE 1-7
Cisco CCNP
Vince_Whirlwind
Trusted Contributor

Re: Topology questions for dual 5820 and dual 2910 switches

Where I have used 2910s as top-of-rack switches, it is (obviously) to support hosts that require 1Gb connectivity. I then use the 10Gb module on the back to create uplinks to the "Core".

For those hosts, ideally they have multiple NICs, and the 2nd NIC patches to a 2nd 2910, and the links are configured in an Active/Standby arrangement.

 

Then, when I can replace the 2 2910s with 2 5800s, I can IRF the 2 5800s, then the two NICs can become Active/Active link-aggregated.

 

You will totally get this once you've set them up.

abc0a
Occasional Contributor

Re: Topology questions for dual 5820 and dual 2910 switches


Pete W wrote:

 

The 2910al does not therefore form a stack, it simply has optional 10GbE interfaces that are useful for interconnecting switches.

 


Here is another good explanation of interconnecting 2910s vs IRF 

http://h30499.www3.hp.com/t5/Switches-Hubs-Modems-Legacy-ITRC/stacking-2-HP-Procurve-2910al-switches/m-p/4792179/highlight/true#M26075