This post is a quick reference notes for myself on how I managed to rectify some of long pending IT related issues which were left by previous network team, including AD Domain S.L.D migration to FQDN / Public IP scheme being used at Private LAN & its migration to multiple /24 Private IP Pools, Single default VLAN-1 migration to Different VLAN’s with smaller subnets.
The number of desktop/laptop/devices were in several hundreds. Downtime was not an option, therefore we managed to complete the task using parallel topologies for each segment.
Our existing network was running on default VLAN with /8 flat subnet, having each & every device on default VLAN-1 generating enormous number of broadcasts flooding causing network delays/timeout. There was no control on any switch segment, All switch edge port were set on Default roles making situation even worst from Spanning-Tree protocol flooding perspective. Above all like Cherry on the TOP, existing admin used public IP scheme with /8 subnet & many websites which were on this subnet over the internet, never worked on our network.
To over come these issues without any Downtime or disruption, I decided to sort issues on a one by one basis by creating parallel network, using below methods
SLD/FQDN Migration:
- On same network, I added new FQDN A.D Domain, Established two way trust between both domains. Then using Microsoft migration tool (ADMT ), I start migrating users (one by one, targeted activity ) from old SLD to FQDN. More details are documented in another article.
