Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

ESX cluster loses network connectivity if change to layer3 switch

Posted on 2014-09-08
2
Medium Priority
?
515 Views
Last Modified: 2014-09-08
Experts, I have a connectivity issue with VMWare that I can't seem to resolve.

I have an ESX 5.5 lab that's currently working as configured under a "Router on a Stick" scenario.

ESX Host  *Vlan 2
VMs *Multiple Vlans             --> Layer 2 Switch --> Layer 3 Router (Gateway 10.x.x.x per each vlan)
iSCSI *Vlan 8
NAS *Vlan 2

Everything works fine, but as the L2 switch is capable of L3, I'd like to simplify the configuration, and get wire speed between the different subnets.  Unfortunately, when I remove the above configuration and set the gateway IP addresses up as a virtual interface on the switch.  This is where it breaks.

ESX Host  *Vlan 2
VMs *Multiple Vlans             --> Layer 3 Switch (Gateway 10.x.x.x per each vlan) --> Layer 3 Router (Sending default route)
iSCSI *Vlan 8
NAS *Vlan 2

Moving the L3 back from the router, and into the switch - works on ALL of the devices (iSCSI/NAS, etc.) - but the ESX hosts immediately drop connection and I can't reconnect to them at all.  With the updated configuration, I'm able to access the iSCSI devices, as well as the NAS boxes that I have, even in the same server network as the hosts/vm's I'm no longer able to communicate with.

All Vlans I have in the scenario, they're all being tagged down to the esx hosts on all ports.  The only configuration change in any of this, is me moving the gateway IP from the router, down to the L3 switch.

I'm decent in router configurations / as well as esx - so I'm not really needing any configuration guides, but I could use the "powers of the minds" here to reasons as why the hosts would stop talking the way they do, just by changing the gateway to a different device.  I'm leaning towards the issue being arp cache, but can't confirm this is the issue, as the other devices in the same vlans have no problems after the change - only ESX is exhibiting this behavior.  That, and I've power-cycled the hosts after changeover too.

Would anybody have any ideas on where I can point the "stick of troubleshoot" at?  *FYI, the L3 switch is a Brocade 648P-POE, but not that it matters.
0
Comment
Question by:usslindstrom
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
2 Comments
 
LVL 5

Accepted Solution

by:
usslindstrom earned 0 total points
ID: 40311043
That was exactly it.  VMWare has articles describing the issue, for those interested:

Cmd introduced in ESX 5.5 (http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2049667)
0
 
LVL 5

Author Closing Comment

by:usslindstrom
ID: 40311044
I'm awesome.
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

WARNING:   If you follow the instructions here, you will wipe out your VTP and VLAN configurations.  Make sure you have backed up your switch!!! I recently had some issues with a few low-end Cisco routers (RV325) and I opened a case with Cisco TA…
This program is used to assist in finding and resolving common problems with wireless connections.
This video shows you how easy it is to boot from ISO images for virtual machines with the ISO images stored on a local datastore on the ESXi host.
In this video we outline the Physical Segments view of NetCrunch network monitor. By following this brief how-to video, you will be able to learn how NetCrunch visualizes your network, how granular is the information collected, as well as where to f…

670 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question