IP routing question

Is it possible for an ISP to provide a second subnet (different from the one used on the router serial links) and allow it to be used for externally accessible devices?  If so how is this accomplished?  Can the ISP route the new subnet to the existing one?  Currently we have a /28 subnet on our serials, and we are running out of avaialable addresses for externally accessible devices.  Can they just add an additional /27 subnet without changing the addressing of the interfaces and already configured devices?  Please excuse my ignorance in these matters.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Yes this is possible, the ISP will route the new subnet via the existing addresses.  The router or firewall that you already have must be capable of handling the additional addresses either through NAT or by routing to an attached interface on the device.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
A word of warning - many ISPs will want you to renumber rather than continue to hand out additional small blocks.

NAT will be the best solution for your need. Going for additional subnet involves cost.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.