Hey the_sim
Three types of VSF MAD
- OOBM - 5400s only (no OOBM port on 2930Fs)
- LLDP - two memebers only
- VLAN - 2930F only as far as I remember, and it's stupidly simple as (I think) it just uses broadcasts to perform MAD.
So, can I use a generic switch to use VLAN MAD? Yes - I would recommend a dedicated VLAN that isn't present on other ports or for other purposes.
Do I need the MAD VLAN on the MAD switch? Well, you configure the 2930F ports as untagged so you can use any VLAN number you chose on the MAD switch --- but I would try to use the same untagged VLAN number if you can configure the switch. You can use an unmanaged switch so that should answer the question :)
If the MAD switch fails, nothing happens if the VSF is working other than MAD stops. MAD fails when VSF becomes disjoint.
Load Balancing will happen by default over the VSF. It's interesting to note that with Aruba switches, front plane stacking, such as VSX and VSF uses shortest-path forwarding by default. This means that if there is an upstream / downstream LAG it will take this path first before using the load balancing hashing algorithm. the hashing algorithm kicks in if there is more than one uplink / downlink port on a single member VSF/VSX switch. The reason for shortest-path forwarding (I just made up that term - not sure what we call it inside Aruba) is it reduces the potential traffic across the VSF/VSX links as traffic will prefer the direct path, not the ISL path. This can play an important part in the design of VSF/VSX as you might not need 8 ports between your member switches - but it depends what your uplinks are and how much east-west traffic there is.
Configure MAD before you connect it, otherwise broadcast storms can occur.
switch(config)# vlan 999 name VLAN-MAD
switch(config)# vlan 999 untag 1/47,2/47,3/47,4/47,5/47
switch(config)# vsf vlan-mad 999