I don't have too much experience with Cisco switches but my company will be implementing them soon.
I'd like to know how to accomplish the following:
let's say we have 2 vlans, vlan 10 and vlan 15.
2 different sets of equipment are connected to vlan 10 and vlan 15, respectively.
Is it possible (and how) to keep vlan 10 passive (in down state) until either a) utilisation of vlan 15 falls below a certain treshold (meaning the equipment connected to it has failed) or b) utilisation of vlan 15 exceeds a certain treshold (meaning there's too much traffic passing throuhg vlan 15 and extra capacity is needed) ?
As far as I know there's no way to do this, and I'm not sure what you want to do makes any sense.
VLANs create completely separate broadcast domains. You can connect servers to multiple VLANs for example, using a 802.1q trunk (I think there are NIC cards out there that will do this), but these VLANs are still fixed bandwidth. You can use etherchannel to bond multiple ethernets ports together to increase bandwith as well.
Not sure how you plan on using the two vlans in question. Maybe some more details?
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...