AW: Setting Framed-MTU Attribute

[Matthew Newton]

On 23/03/2022 15:28, Luca Bertoncello wrote:
> I read the site-available/default but since I don't know what I have to search for, it's very difficult...

As Alan said, the default config is full of examples of how to update 
attributes. You just have to read it. Updating attributes is also 
documented in the unlang man pages.

e.g.

https://github.com/FreeRADIUS/freeradius-server/blob/v3.0.x/raddb/sites-available/default#L864-L867

> Currently, I tried to change the mods_enabled/eap and set use_tunneled_reply to yes.
> I also changed the mods-config/attr_filter/access_challenge and added Framed-MTU = 1344 at the start of the "DEFAULT" section.
> No changes in my situation.

Because as you've already been told, attr_filter *removes* attributes, 
it doesn't add them.

update reply {
   Framed-MTU := 1000
}

 From your original post, though, I suspect this won't help. That 
attribute is for telling the NAS what MTU to use. It won't make its way 
through to any device on wifi.

If you have a VPN in the way of that RADIUS server that's causing MTU 
problems, drop the MTU on the NAS or RADIUS server, or fix the VPN / 
PMTUD so that the path MTU is calculated correctly. You can't fix that 
by changing attributes.

-- 
Matthew