If I have a dual band router, do I need a dual band modem?

[suh8lim3]

I saw on my ISP's website there's an option to upgrade my modem to dual band, but my current router is dual band and I'm able to access 5ghz already. Is the upgrade necessary, or even helpful at all?

 

[kanewolf]

If there is a dual band "modem" listed on your ISP site, then it is a modem/router combo unit. If you have a dedicated router then you don't need the ISP router.