2.5g is kinda a odd ball. Enterprise stuff has long used 10g ports and there is little reason to use 2.5g or 5g stuff becuase there is no longer a huge price difference.
2.5g seems to be something they are selling to home users even though I am not sure why they did not just use the 10g stuff.
In any case your problem is the only router cpu used on consumer grade routers that can do this is BCM4908. You will find this chipset in every router that I know of that has a 2.5g wan port. Maybe there is another chipset in development that has the ability to run more 2.5g ports but this information is likely hidden away in much more technical forums that this one.
There are companies like mikrotik that make more advance routers but unsure of one that has 2.5g ports. There are a number of ones that have 10g ports. So maybe you could place 2.5g/10g switches in between to convert the speed. If you had asked about a router with all 10g port there are a fairly large number of those.
Read the specs very carefully. Many of these devices use general purpose cpu chips. The ones you find on consumer router have the ability to run the NAT in hardware offload. You have to look at the actual rates they can pass. Note on consumer routers if you use pretty much any feature that need the cpu to look at the data steram you will lose this hardware accelerator which is another reason people buy routers from companies like mikrotik.
In the end are you really sure it is worth the effort. There is very limited use of very fast internet,most people can't really use 1gbit. In addition you will find that the disk storage systems in your pc will limit you fairly quickly when you start to look at high speed.
Facebook
Twitter
Instagram