Setting Framed-MTU in Freeradius

[Alexander Clouter]

On Fri, 27 Feb 2026, at 09:19, Nick Porter wrote:
>
> There is some incorrect information out there which claims that setting 
> Framed-MTU will influence the client -> server EAP fragment sizes.  That 
> is simply not the case.  That attribute can be used in an Access-Accept 
> for setting the MTU on the connection which is being authenticated, but 
> it has nothing to do with the packets involved in doing the authenticated.

Probably a lot of that confusion is from the affect of its presence in an Access-Request as a hint to the server[1][2].

Cheers

[1] https://datatracker.ietf.org/doc/html/rfc2869#section-2.3.3
[2] https://github.com/FreeRADIUS/freeradius-server/blob/2f2f28f43b4f52f18ef8d4c08e9f08d8a977148b/src/main/tls.c#L817-L864