How do you handle Route Domains?

They're a great tool, but they have a few "rough edges" it can be helpful to be aware of.

When we were running big multi-tenant systems I coupled them with partitions so we could have per-partition subnets with their own default routes pointed out to the customer's firewall. This required per-customer VLANs, self-IPs. A plus for this was that it allowed us to move customers' services around between prod and DR without disturbing any other clients.

A more recent need was to ease a migration where multiple F5 LTMs were being merged and consolidated. An IP overlap of sorts occurred where I needed to use the virtual servers from one group of systems as the pool members for another group of virtual servers. Using the route domain to create a clone of my subnet allowed this, otherwise trying to use a virtual server as a pool member on the same box will not work.

A rough edge I can recall are certain limitations with APM, as well as certain advanced health monitors (Oracle DB is one) would fail due to compatibility problems.

That said, I don't use them if I don't need them, but when I do need them, they are a life saver.