https://www.arubanetworks.com/techdocs/AOS-CX/10.09/HTML/vsx/Content/Chp_Start/get-sta-wit-vsx.htm
Aruba Virtual Switching Extension (VSX) is virtualization technology for aggregation/core switches running the AOS-CX operating system. This solution lets the switches present as one virtualized switch in critical areas. Configuration synchronization is one aspect of this VSX solution where the primary switch configuration is synced to the secondary switch. This solution allows for a pseudo single plane of glass configuration and helps keep key configuration pieces in synchronization as operational changes are made. Since the solution is primarily for high availability, it is expected that most of the configuration policy is the same across both peers.
VSX virtualizes the control plane of two aggregation switches to function as one device at layer 2 and as independent devices at layer 3. From a datapath perspective, each device does an independent forwarding lookup to decide how to handle traffic. Some of the forwarding databases, such as the MAC and ARP tables, are synchronized between the two devices using a proprietary VSX control plane. Some of the forwarding databases are built independently by each switch.
Most of the initial config has been taken from the guides on the Arubas VSX Pages
These are some snippets from the initial config setup, the config statements shown are only the bits that differ from the default switch configuration.
The vsx-sync commands are not needed for the system to work, these commands will allow for the config to be automatically updated on the peering VSX switch, however, if the configuration is added on to both switches manually things should still work.
Although I played with this syncing for the VLAN's I didn't enable it for anything else initially as I like to understand how and what each bit of config does instead of just enabling everything and wondering how different parts interact.
vlan 20
vsx-sync
vlan 999
interface lag 1 multi-chassis
no shutdown
no routing
vlan trunk native 999
vlan trunk allowed 20
lacp mode active
interface lag 3 multi-chassis
no shutdown
no routing
vlan trunk native 999
vlan trunk allowed 20
lacp mode active
interface lag 128
no shutdown
no routing
vlan trunk native 999
vlan trunk allowed all
lacp mode active
interface 1/1/1
no shutdown
lag 1
interface 1/1/3
no shutdown
lag 3
interface 1/1/47
no shutdown
ip address 192.168.100.1/30
interface 1/1/48
no shutdown
lag 128
interface vlan 20
ip address 10.0.1.250/24
active-gateway ip mac 00:00:00:00:00:01
active-gateway ip 10.0.1.254
vsx
inter-switch-link lag 128
role primary
keepalive peer 192.168.100.2 source 192.168.100.1
vlan 20
vsx-sync
vlan 999
interface lag 1 multi-chassis
no shutdown
no routing
vlan trunk native 999
vlan trunk allowed 20
lacp mode active
interface lag 3 multi-chassis
no shutdown
no routing
vlan trunk native 999
vlan trunk allowed 20
lacp mode active
interface lag 128
no shutdown
no routing
vlan trunk native 999
vlan trunk allowed all
lacp mode active
interface 1/1/1
no shutdown
lag 1
interface 1/1/3
no shutdown
lag 3
interface 1/1/47
no shutdown
ip address 192.168.100.2/30
interface 1/1/48
no shutdown
lag 128
interface vlan 20
ip address 10.0.1.251/24
active-gateway ip mac 00:00:00:00:00:01
active-gateway ip 10.0.1.254
vsx
inter-switch-link lag 128
role primary
keepalive peer 192.168.100.1 source 192.168.100.2
trunk 49-50 trk1 lacp
vlan 20
name "VLAN20"
untagged 1
tagged Trk1
no ip address
exit
trunk 49-50 trk1 lacp
vlan 20
name "VLAN20"
untagged 1
tagged Trk1
no ip address
exit