The tilde is the first question

/mgmt/tm/ltm/pool/~Common~apps~web_pool

That addresses /Common/apps/web_pool. The tilde is a folder separator, and it exists for a plain reason: a URL already uses the slash for its own structure. BIG-IP objects live in partitions and folders whose separator is also a slash, so iControl REST substitutes the tilde and the ambiguity disappears.

Once you know that, the rest of the path reads in order.

The shape

/mgmt is the management root. /mgmt/tm is the TMOS configuration tree — the objects tmsh manages. /mgmt/shared is a different thing: the shared worker space, where iApps LX, file transfer and licensing live.

The module comes next: ltm, gtm, net, sys, security, asm, apm, auth, cm. It tells you which subsystem owns the object, and it is the same division tmsh uses.

The collection follows — pool, virtual, node, monitor. Address it alone and you get every object in it.

The object is the tilde-encoded part. A sub-collection may follow, and pool members are the one everybody meets.

The partition detail that causes 404s

A name written without a partition — /mgmt/tm/ltm/node/web1.example.net — is resolved in the caller's current partition. The same request can therefore succeed for one administrator and return a 404 for another, with nothing wrong in either case. If a script works for you and not in production, check which partition the service account is in before checking anything else.

Query options change the size of the answer

  • $select returns only the properties you name. The single most effective way to shrink a large response.
  • $filter filters server-side, most often partition eq Common.
  • expandSubcollections=true inlines sub-collections instead of returning links to them.

That last one explains the most common surprise in iControl REST: a pool comes back with no members. The members are a sub-collection, and they are not included unless you ask.

And the other API

A BIG-IP tenant on VELOS or rSeries sits on top of F5OS, which is driven by RESTCONF over YANG rather than by this object model. The paths look nothing alike, and the reason is that they come from different traditions rather than different versions. The companion article on F5OS paths covers that side.