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c3000 mapping physical ports to blades

 
Tim Wilkinson
Occasional Contributor

c3000 mapping physical ports to blades

Hi,

I'm finding the netwroking a bit complicated in the c3000, even for the basic stuff.
There are 2 Cisco Catalyst 3020 Switches (in Interconnect Bays 1 & 2) and I can't for the life of me work out how the ports are mapped to the blade servers.

I've looked at the 'port mapping' and I find it and completely unintutitive. I click on Interconnect Bay 1 and it appears that 2 ports are assigned to each blade (by clicking on each blade's port mapping you can tell which blades map to which ports) but when I click on Interconnect Bay 2 it just reports 'no connection'. The switch in Bay 2 appears to be working. Have I got this in the wrong slot or something? This confusion is before I've even plugged any of the switch ports in.

Once I plug the actual switch ports in (from either switch) there are link lights but how do I know or define which blades are using which physical ports?

What I'm trying to do is have some sort of redundancy so if one of the switches dies, each blade will still be able to connect to the network.

Essentially, I'm just trying to make sense of how the networking works in the c3000. I'm going through various links and HP PDFs but still finding it difficult to make sense of this.

Any help is appreciated.

Cheers,

Tim


6 REPLIES
siukalo
Advisor

Re: c3000 mapping physical ports to blades

On the c3000, all LOM (Onbaord nics from blades) are all hardwired to IB1 (Interconnecting bay 1). The first connection from Blade in bay 1 will be on port 1 of c3020, second connection is on port 9 of c3020, etc.

To get connections on IB 2, you need to add a mezzanine card in slot 1 of the blades (The higher slot on the blade mnotherboard). All ports on that mezzanine card will then be hardwired to IB 2.

To have connections of IB 3 & 4, add mezzanine card in slot 2 of blades (The lower slot on the mothboard), then they are hard wired to IB 3 & 4.

Hopes this helps.

Alan
Best Regards

Alan
siukalo
Advisor

Re: c3000 mapping physical ports to blades

Your next part of the question..

In c3000 in that matter, you cannot choose which port the nics goes to which IB, it is hardwired. If you need redundancy, you will need to consider that in your OS and infrastureture design, this cannot be done on the chassis, as both LOM connects to IB 1.

If you need redundancy, then you will need to add a mezzanine card into Slot 1 on the server, then take LOM1 and mezzanine P1 and load balance across these 2 links. (Which means LOM1 goes to IB1 Port 1 on c3020 and mezzanine P1 goes to IB 2 Port 1 on c3020)

As for your question about "Once I plug the actual switch ports in (from either switch) there are link lights but how do I know or define which blades are using which physical ports?"

It is a switch so you don't really care which port it goes into and out of the switch. I think you might be thinking this is a pass through. In a pass through then you need to know which is which, but it is a switch. All you need to worry about is how to have a different path out of the chassis say if the c3020 in IB1 dies. The chassis itself cannot do this for you, you will need to do this in your OS or infrastructure design.

Alan
Best Regards

Alan
gregersenj
Honored Contributor

Re: c3000 mapping physical ports to blades

The technology brief, give you a good understanding:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01508406/c01508406.pdf

If you don't know the C7000, you may think, why did they make it this way.
Well, the C3000 is half a C7000. They simply cut the redundant side away.

So if you also take your time reading the C7000 technology brief, is become very logical.
C7000 Technology brief:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00816246/c00816246.pdf

BR
/jag
Tim Wilkinson
Occasional Contributor

Re: c3000 mapping physical ports to blades

Thanks siukalo and gregersenj. Points will be on the way soon :)

siukalo - I have been thinking of this switch as a bunch of NICs rather than a switch (I knew it was a switch but wasn't really sure what that meant in this setup as servers are generally connected to netwrok via NICs.
I think I'm understanding it a bit now - that the first 16 ports are internal and 17-24 are physical ports. I've noticed that if I plug ports from 17-24 into netwrok, the switch enables the first port and then all other ports show status of disabled but I'm unsure why. Am I supposed to plug uplinks into the SFP ports?
What I'm wanting is to have 4 NICs available for each blade as I'm using them for ESXi hosts - 2 NICs will not really be enough per blade.

gregersenj - I'm currently wading through the technology guide so hopefully by the time I get to the end I'll understand this all a bit more :)

Thanks
siukalo
Advisor

Re: c3000 mapping physical ports to blades

The reason why I think the other ports are disable is because you connected the c3020 to another switch without configuring any form of LAG/FEC on the links. So STP ( Spanning tree ) kicked in and elimated the routing loops.

You can aggregate all of those 8 ports on the c3020 as 1 big uplink using port channel command and the channel group command in c3020 IOS.

If you want to have 4 nics avaliable to each blade and have them in different IB. You will need to buy a mazznine card and put it into slot 1 of the motherboard. Then the 2 LOM will be on IB 1 and mazznine card will be on IB2.

Hopes this clears it up for ya.

Alan
Best Regards

Alan
gregersenj
Honored Contributor

Re: c3000 mapping physical ports to blades

For a VMWare setup, Virtual Connect Flex 10, is worth to take a look at.

There's a Virtual connect for dummies, for free download.

BR
/jag