Trunks between HP GbE2c and V1810-48G switches

[jdixon]

I am working on configuring our network so we could lose a switch in the c7000 enclosure and one of our V1810 layer-2 switches while still remaining online.

This is what I have:

• One c7000 Enclosure
• Two HP GbE2c ethernet modules in the enclosure
• Two HP V1810-48G layer 2 switches.

Now right now I have a trunk that is linking the two V1810-48G switches together. How can I trunk the connections between the enclosure to the switches without creating a loop?

It is my understanding that those modules have an interconnect trunk that links the two switches together within the enclosure. So can I trunk one GbE2c to the top v1810-48G switch and trunk the other GbE2c to the bottom v1810-48 switch without any problems?

I have attached a picture of what I'm trying to do.

[paulgear]

Hi jdixon,

This question really belongs in the V series forum: http://h30499.www3.hp.com/t5/Web-and-Unmanaged/bd-p/switching-v-series-forum

However, the short answer is that you need to have spanning tree (STP/RSTP) support turned on in your network. I think the 1810s support this. The switches in your blade enclosure should also support (R)STP, and it should be turned on there, too. If my suspicions are correct, the blade switches are likely far more capable than the 1810s, and you probably should set their priority fairly low so that they become the root and secondary root in the spanning tree.

[jdixon]

Thank you for the information.

The blade switches are layer 3 and the V1810's are layer 2. The V1810 do not have spanning tree but have something called "Flow Control" and "Loop Protection". The loop protection just shuts down the ports if it suspects a loop which isn't what I need.

[paulgear]

I haven't played around with the loop protection feature for a while, but from memory all it can do is shut down a port when it notices a loop. I don't think it can turn it back on once the loop is gone. If that is the case, i wouldn't recommend deploying it in a production server environment, but would suggest upgrading to fully-managed switches instead.

[jdixon]

Unfortunally we won't be able to upgrade those switches for a little while.

What I did do however is disable the interconnect ports of the GBE2c modules which would cut out the loop. I will just have to bond the nics of the blade servers to get redunandcy between the two modules for now.

Do you see any problems with doing this?

Thanks for all the help you have given so far btw

[paulgear · Accepted solution]

I think you'd be better off investigating the features of those GbE2c modules. From what i can tell in a few quick web searches, they're a pretty decent switch (rebadged Nortel). You could turn on spanning tree in them and compensate for the dumb switches you have on the front end. It just means that if you need to communicate from one switch to the other you would have to go through the front end switches. But it should work.

I'm not really familiar with how bonding works in blade chassis, so i'll leave it to others more qualified than myself to comment.

Good luck!

[jdixon]

Thanks for all the information.

So I can enable spanning tree on those two modules and still be ok? Right now I disconnected the interconnect links between the modules and ended up with some weird issues.

For example I have two servers on VLAN 10. These two servers cannot ping each other but can ping some other devices on VLAN 10. I don't really get it. For example:

FS01 = 10.1.3.15

FS02 = 10.1.3.16

DC01 = 10.1.0.5

DC02 = 10.1.0.6

FS01 and FS02 can ping both DC01 and DC02.

FS01 cannot ping FS02 and FS02 cannot ping FS01. The only difference is both the FS servers are located within the same enclsoure while the DC01 and DC02 are located on a ESX server connected to the V1810-48G switches.

So it sounds like I can turn on spanning tree on those modules and connect the interconnect links back up right? Is that what you mean? I'm assuming this will fix the loop issue as well?

[paulgear]

I don't know enough about those blade modules to answer the question authoritatively, but my guess is that turning on spanning tree and connecting all the links should work. You should consult a better source of information on those switches to be sure.

[jdixon]

Thank you for all your help. I will see about reposting to another forum on here if I find one relating to those switches.

Thanks again for your assistance!