SDX Management traffic flow

[Gordon Curry]

Hi all

I'm trying to understand the management traffic flow for SDX / VPX and cannot find anything documented.

I have recently deployed an SDX and this has a couple of VPX instances on it, all working fine. The SDX has the management interface (0/1) connected and 2 fibre SFP modules which are setup as a channel (LA/1) and this is the only interface added to the VPX. The option 'Manage through internal network' is enabled on the VPX so management traffic from the SDX to the VPX will be internal to the SDX.

My understanding was that all traffic connecting to the NSIP of the VPX, i.e. connecting to the web GUI, would use the LA/1 channel. However, we have found that even with the SFP's disconnected we are still able to connect to the web GUI of the VPX. The only physical network connection in the SDX is the 0/1 management interface and so even though we are connecting to the NSIP of a VPX (not the SDX SVM IP) it appears that the traffic must be connecting to the SDX 0/1 port and from there to the VPX.

Management VLAN setting is set to L2VLAN.

Is anyone able to shed any light on this, thanks.

 

 

[Michael Adam]

Hello @Gordon Curry,

 

when "Manage Through Internal Network" is enabled on VPX via SVM, an additional internal interface is bound to the VPX. This interface will be numbered 0/1, 0/2, or 0/3 depending on whether other management interfaces are also bound.

On SDX it will be listed as 0/3 with an internal IP address in the 169.254 address space. 

 

With this interfaces on SDX/VPX the communication ist established. For more information see here: https://www.citrix.com/blogs/2020/06/10/citrix-adc-sdx-to-vpx-always-on-reachability/amp/

 

Best regards,
Michael 

 

For more information 

[Gordon Curry]

thanks @Michael Adam, I understand the "Manage Through Internal Network" feature but I don't understand how I can still access the web GUI of a VPX when the only physical connection to the SDX is the management port (0/1). Does all management traffic to the VPX instances pass through the SDX management interface?