4 ms·
Their solution is based on per-subscriber VLANs. VLANs have a 12-bit ID, so 4096 maximum. In practice there are usually fewer available, some ranges being reser
by AceJohnny2 9y ago
Their solution is based on per-subscriber VLANs. VLANs have a 12-bit ID, so 4096 maximum. In practice there are usually fewer available, some ranges being reserved by network infrastructure.
And indeed:
NB: Per the spec, the maximum number of VLANs on a network is 4094. In our case, it is not an issue, as our subscriber count should not exceed 3500 in the foreseeable future. If we were to exceed it, we would need to look at other solutions.
That's one hell of a caveat. It works well for them because French universities (this is deployed at SupElec, one of them) are usually small, but wouldn't pass muster in most US situations.
- solotronics 9y agomaybe I have been looking at datacenters too much lately but I think you could probably achieve the same thing and better scale + performance with something like VXLAN EVPN down to the switch instead of vlan per user. the end user would have interesting stuff like MAC mobility too so it would be suitable for the staff and servers as well as student network edit: yeah that would be awesome, you could move a VM from a server to your laptop with minimal interruption https://www.juniper.net/documentation/en_US/junos/topics/concept/evpn-vxlan-data-plane-encapsulation.html https://www.juniper.net/documentation/en_US/junos/topics/con...
- vbernat 9y agoStudent staff usually learn first network tricks on their first year and stay for 3 years. Complex solutions cannot be used because they don't have the experience and even if they get it quick enough, this would put a huge barrier to yearly new comers.