This article describes the flow of High Availability packets when various combinations of tagging are implemented in the NetScaler configuration. For additional information on HA traffic not seen on tagged channels refer to CTX201788.

Flow of High Availability Packets

Heart beats, that is High Availability packets, are always untagged unless the NSVLAN is configured using set ns config -nsvlan command or an interface is configured with the -trunk on option in NetScaler software release 9.2 and earlier or -tagall option in NetScaler software release 9.3 and later.

The following scenarios help in describing the flow of the High Availability packets:

Scenario 1

NSVLAN is default (VLAN 1)
interface 1/1 is bound to VLAN 2
Interface 1/2 is bound to VLAN 3

add vlan 2
add vlan 3
bind vlan 2 -ifnum 1/1
bind vlan 3 -ifnum 1/2

High Availability packets flow as untagged on the 1/1 and 1/2 interfaces on the native VLAN (of those interfaces - 2 and 3 respectively).

Scenario 2

NSVLAN is default (VLAN 1)
interface 1/1 is bound to VLAN 2, which is configured with -trunk ON
Interface 1/2 is bound to VLAN 3, which is configured with -trunk OFF (default)

set interface 1/1 -trunk ON
add vlan 2
add vlan 3
bind vlan 2 -ifnum 1/1
bind vlan 3 -ifnum 1/2

High Availability packets flow on 1/1 as tagged with a VLAN ID of 2 (as all other native packets of this interface), and untagged on the 1/2 interface.

Scenario 3

NSVLAN is VLAN10 (non default)
interface 1/1 is bound to VLAN 2
interface 1/2 is bound to VLAN 3
interface 1/3 is bound to VLAN 10

add vlan 2
add vlan 3
bind vlan 2 -ifnum 1/1
bind vlan 3 -ifnum 1/2
set ns config -nsvlan 10 -ifnum 1/3

High Availability packets flow as tagged (default) on VLAN 10, interface 1/3 only and do not flow on VLAN 2 or VLAN 3.

Tagged: This indicates 802.1q with native VLAN support, similar to “trunk” in Cisco.

Trunk/Tagall: This indicates the port is in the trunking mode with no native VLAN support, which indicates that all the VLANS are tagged including the native VLAN. This option was made available for compatibility with some force10 switches. “Trunk” in NetScaler is an equivalent of “Tag native VLAN” in Cisco.

Notes: High Availability Heartbeat packets are always sent using the native VLAN, so if an interface is in Trunk/Tagall mode, High Availability heart beats are tagged with the interface Native VLAN ID.
For adding a subnet to a specific VLAN use the following command:
bind vlan <vlan-#> -ipAddress ip-address mask

CTX115575 - FAQ: The "trunk" or "tagall" Option of NetScaler Appliance
Citrix Documentation -  Restricting High-Availability Synchronization Traffic to a VLAN