Who do I ask for a reference after a layoff? - what worked for you?

I worry a reference will only confirm dates of employment. I do not usually post, so bear with me. A colleague offered to vouch for me. How do you ask politely?

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.

Use a professional network to find a former manager. Many will still write a note.