topic Re: c7000 MultiStack with VLAN Tunnel & SUS in BladeSystem - General

c7000 MultiStack with VLAN Tunnel & SUS

mc_rae — Tue, 25 Mar 2014 18:25:30 GMT

Hi,

i have 2 enclosures connected as a multi stack. Each chassis has 2 Flex10 modules. 2 uplinks should be used for VLAN tunnel and 2 for SUS traffic. The uplinks will be bonded

To create the uplink sets should i group 1 uplink on bay1 of enclosure1 and 1 uplink from bay2 of enclosure2 for VLAN tunnel and the same for the SUS?

Or should i.e. the uplink set for VLAN tunnel be created with 2 uplinks on bay 1 of enclosure1 and the uplink set for SUS with 2 uplnks on bay2 of enclosure2?

Thanks for your help

Re: c7000 MultiStack with VLAN Tunnel & SUS

Psychonaut — Tue, 25 Mar 2014 21:51:12 GMT

Option 2 - as the links have to come out of the same interconnect for the connections to be Active/Active.

In the past I setup 4-wide stacks that way with SUS-A in enc0:Bay1 and SUS-B in enc3:Bay 2 (Active/Active) and it worked great.

Re: c7000 MultiStack with VLAN Tunnel & SUS

mc_rae — Wed, 26 Mar 2014 08:38:13 GMT

Hi and thanks for your feedback,

got it. In oder to have active/active uplinks the uplink set needs to stay on 1 module

I tought to implement option 2 but is this setup not prone to a single point of failure?

I got doubtful about because what kind of failover is available when i.e. the encl1 bay1 module with the Gbics for the VLAN tunnel uplink set will fail?

The CX4 interconnection to the other module on encl2 bay1won´t help from my view as this module do not have Gbics for the uplinks to the external switch. The SUS uplinks don´t help as they serve different VLANs.

Re: c7000 MultiStack with VLAN Tunnel & SUS

Steven Clementi — Wed, 26 Mar 2014 12:23:44 GMT

"I tought to implement option 2 but is this setup not prone to a single point of failure?"

No. You're server configuration would/should include 1 nic that passes traffic on one VC module and a second NIC on a different module. That being said, you should also have 2 SUS's and 2 tunneled so that each nic can use a different path to the network.

"I got doubtful about because what kind of failover is available when i.e. the encl1 bay1 module with the Gbics for the VLAN tunnel uplink set will fail?"

See above answer/comment.

"The CX4 interconnection to the other module on encl2 bay1won´t help from my view as this module do not have Gbics for the uplinks to the external switch. The SUS uplinks don´t help as they serve different VLANs."

Proper stacking would/should produce a route to any link in either direction. Modules are stacked between enclosures, but they also have cross connects so theoretically traffic could pass from a module with a failed uplink, to the module next to it, up through it's stacking cable to the other enclosure, and either out through the uplinks there, or across to the paired module and out through it's uplinks. (thus the reason to have a pair of uplinks for each sus or tunneled network link.)

Re: c7000 MultiStack with VLAN Tunnel & SUS

mc_rae — Wed, 26 Mar 2014 14:25:43 GMT

Thanks for your post.

Ok let me repeat if i understood correctly.

i.e. Instead of having 1 tunnel with 2 bonded uplinks and 1 SUS with 2 bonded uplinks i create 2 tunnels with 1 uplink per tunnel and 2 SUS with 1 uplink per SUS?

Assuming i have 2 Gbics on encl1 bay1 and 2 Gbics on encl2 bay2.

Tunnel A: 1Gbic encl1 bay1

Tunnel B: 1Gbic encl2 bay2

SUS A: 1 Gbic encl1 bay1

SUS B: 1 Gbic encl2 bay2

I hope i got it correctly...

Re: c7000 MultiStack with VLAN Tunnel & SUS

mc_rae — Thu, 27 Mar 2014 15:37:01 GMT

Hi,

would this be a sufficient setup?

Any recommendations?

Re: c7000 MultiStack with VLAN Tunnel & SUS

mc_rae — Wed, 02 Apr 2014 11:35:21 GMT

"Option 2 - as the links have to come out of the same interconnect for the connections to be Active/Active. "

The mentioned option 2 in a mixed mode setup with VLAN tunnel and VLAN mapping(SUS) won´t work if they provide different VLAN support on the uplinks, i.e. VLAN tunnel has assigned VLAN 100-200 and VLAN mapping(SUS) VLAN 300-400.

Assuming flex module in encl0 bay1 fails. It has VLAN tunnel uplinks for VLAN 100-200. The CX4 stacked module on encl1 bay1 can´t provide a failover for encl0 bay1 as it has no uplinks. Traffic for VLAN 100-200 will be just accessible inside the chassis. But traffic for VLAN100-200 from external won´t reach the multistack.

Also the affected VLAN 100-200 traffic can´t move through the internal stack link to the module encl1 bay2 as it just has uplinks for VLAN mapping (VLAN300-400)

The same problem occurs if the module on encl1 bay2 where the VLAN mapping(SUS) uplinks reside breaks.