Air carrier Captain reported GPS jamming while on an arrival to an airport in international airspace. The flight continued to the airport on vectors from ATC and completed a ground based ILS to a landing.

Narrative

While flying the DUMAP9z arrival into PEK at approximately 18;000 we received GPS jamming. I reported this to ATC and dispatch. Luckily the remainder of the flight was essentially radar vectors to an ILS. After turning off the GPS and NAV inhibit we continued the arrival. Once on vectors for the ILS z 1 we were cleared for the approach. Our position was approximately 4 miles east of the localized and about 18-20 miles south and the PF first officer armed the APP (Approach) mode. Within a few seconds the localizer started to capture a false signal east of the actual one. I instructed the FO to reselect Hdg (Heading) mode to keep us on the assigned heading till we got closer to the actual localizer. Once this was done the flight continued as usual. On the ground I did not complete a maintenance write up about the GPS jamming. The 'checklist' for the GPS jamming is more supplementary info and lots of it did not apply to our situation. I think all this extra info and the format of the information caused me to gloss over the section of what to do when on the ground.