On Fri, 11 Jan 2013, John Stoffel wrote:
Richard> Hi! I have a problem that I was hoping I could get some
Richard> advice on. In particular, where to start looking...
Richard> I inherited a Rocks Cluster which I am trying to make
Richard> semi-usable. There are 31 nodes in the cluster, so in order
Richard> to create the cluster network, two Dell switches are used --
Richard> a PowerConnect 5224 and a PowerConnect 5324. The head node
Richard> and most of the computer nodes are plugged into the 5224, and
Richard> the rest are plugged into the 5324 which then is plugged into
Richard> the 5224. The problem that I'm having is that the clients on
Richard> the 5324 cannot be PXE booted properly. If I plug them into
Richard> the 5224, let them boot and install, and then plug them back
Richard> into the 5324, they work correctly, until the next time I
Richard> need them to reboot (to add a package, or something).
Richard> I assume there is some kind of packet that is not being
Richard> properly forwarded by the 5324 (or not being allowed by the
Richard> 5224). What I would like is to convince the two switches that
Richard> they are really one big(ger) switch, so they don't block
Richard> anything from going around. Unfortunately, I really don't
Richard> know much about networking beyond the basics -- in
Richard> particular, I don't know the terminology. Looking at the
Richard> configurations of the switches, I see things like
Richard> "spanning-tree", "bridging", "trunks", etc.
Richard> What should I be looking at? I tried to Google various
Richard> things, but I'm not convinced I even know where to start --
Richard> at least, nothing I've found seems to address my question, or
Richard> at least make sense to me.
Try checking that port-fast is/isn't turn on for the ports. We have a
problem here with our DELL 5224s not working right with our Cisco 4507
running IOS showing the same symtoms. So far I haven't beaten on it
enough to chase down the real config issue, mostly because I only
kickstart once in a while and I don't run the switch and don't want to
run the switch.
John makes an excellent point about portfast. You want that turned on for
hosts (or routers) so that their links come up quickly (it speeds up the
Spanning Tree algorithm by cutting out or shortening some of the steps).
You almost never want portfast enabled on a link that goes to a switch,
trunk or not, as the risk of loops is much higher. I don't think the Dell
switches even let you do that on a trunk, but a Cisco switch will let you
and it does have its uses.
-Nate
Nate also has some good thoughts here, and more details too. Good
luck.
John
_______________________________________________
Discuss mailing list
[email protected]
https://lists.lopsa.org/cgi-bin/mailman/listinfo/discuss
This list provided by the League of Professional System Administrators
http://lopsa.org/
_______________________________________________
Discuss mailing list
[email protected]
https://lists.lopsa.org/cgi-bin/mailman/listinfo/discuss
This list provided by the League of Professional System Administrators
http://lopsa.org/
