10 metre ethernet cable from Openreach VDSL modem to router?

A friend needs some help, and I'm thinking of a temporary-ish setup that would involve running a 10 metre ethernet cable from the Openreach VDSL modem to the main wifi router.

Would this be likely to noticeably/significantly degrade performance/speed, bearing in mind the Openreach VDSL modem will still be right next to the master socket where it comes into the house? I've got the 10m ethernet cable already. I'm not sure if it's Cat5 or Cat6, probably the former.

As it is an Ethernet signal between the modem and the router, there will be no side effects from a 10m cable. Should be good to 100m and maybe even further with a good cable.

Post deleted by RobertoS

Before the g.inp issue was fixed with the hub5a i was using a 10 meter cat6 cable between the modem and hub, it worked flawlessly. as for the type you have it should be written on it saying either cat5, cat5e or cat6.

now im using a 10 meter cat 6 with a rj-45 on the faceplate and a rj-11 on the other for the wan port, i can honestly say ive not noticed the slightest difference between the two.

That will have precisely no effect. Assuming that it's a modern standard (cat6 or cat5e), it will be rated for 100m length, even at gigabit speeds.

Would it be almost as quick and a lot neater to install an RJ45 socket close to the modem, run a Cate5e cable (infrastructure type not patch) to there the router will be located and install another socket there? That can be hidden under floors, under skirting &c. Looks neater and less of a hazard.