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ok - this is beyond my expertise so I need to ask here.

I have a bunch of test hardware that I'm configuring and I'm running into some network problems where I'm not an expert (talk SQL Server to me!).

Here's a simplified description of my network topology:

  • network switch #1, connected to network switch #2, and setup to know that the internet gateway is through switch #2
  • network switch #2, connected to the hub/gateway
  • hub which is a DHCP server, and gateway to the outside world

The MD3000i iSCSI arrays are connected to switch 1. If I power-cycle one, it doesn't pickup an IP address. If I change the hub to be connected to network switch #1 and power-cycle the array again it gets an IP address through DHCP. I'm guessing there's something going on such that the broadcast 'give me a DHCP address' from the iSCSI array isn't being propagated through to switch #2 and to the hub/DHCP server.

Once the array gets an IP address, I need to remove the array and then automatically find it again using the DELL Modular Disk Storage Manager. Should I give them arrays static IPs (on the local network)?

Do I need to have a connection from each switch to the hub/DHCP server? Or am I missing something? I'll provide any info you want to hepl with this as long as I'm able.


PS Tagged with 'sqlserver' only so that the folks I know can follow this question.

share|improve this question
What do you specifically mean by "network switch #1 is configured to know that the internet gateway is through switch #2"? Normally switches aren't configured for anything like that (unless they are doing layer 3 routing) and just pass packets. – Kevin Kuphal Jun 2 '09 at 3:54
His hub/gateway sounds more like a router possibly a small biz one with a switch in it as well – Zypher Jun 2 '09 at 4:04
The hub/gateway is just a regular LinkSys. (This is at home). The switches are DELL PowerConnect 5424 GB switches, with one set to route to the /hub/gateway through the other. Yes, this sounds weird, but we have a 42U rack at home (our office) with 26TB of storage and 3 8-way servers. – Paul Randal Jun 2 '09 at 4:07
My first inclination is that your routing configuration on Switch #1 is faulty. I don't see any reason why you should have layer 3 switching on Switch #1 and I would suggest turning it off. – Kevin Kuphal Jun 2 '09 at 4:13
The one thing i would watch is those dells don't really transfer data enough. I just pulled them out of production (loongg fight very happy to have it done) and our bandwidth graphs went from a constant 10Mbp/s to bursting up to 500-600 Mbp/s. Although we did have about 70 servers attached (VMWare) so YMMV – Zypher Jun 2 '09 at 4:19

To make your life easier just assign them static IPs. Yes the MD3000i can do DHCP but you cannot get around having to remove and re add them. Also when the DHCP address changes, you'll have to go back and reconfigure all of your initiators so that they can talk again.

share|improve this answer
That's what I was thinking would be the easiest route to take (no pun intended :-) So I should be able to assign them static IPs within my private 192.168.1.X subnet, right? Sorry for sounding a little clueless - everyone has to have at least one area they don't know much about. I wrote a bunch of the guts of SQL Server while at MS so really am smart :-) – Paul Randal Jun 2 '09 at 4:09
yep, you should be able to do that - i would check on your linksys to make sure it's assigned outside of the DHCP range. No worries can't know everything right? (although we can try) :) I'm pretty clueless on SQL issues - although i'm being forced to learn to fight our "DBA"'s ideas and put sane stuff in place. – Zypher Jun 2 '09 at 4:17

Do you have spanning tree setup on the switches, and if so, have you set them to portfast?

share|improve this answer
No idea what any of that means I'm afraid, and I should have mentioned that they're DELL PowerConnect switches. – Paul Randal Jun 2 '09 at 4:11

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