function net186_import_filter (int POPID)
    int viaRegion;
    bgppath public_bgp_path;
{
    public_bgp_path = delete(bgp_path, [4200000000..4225479999]);

    if filter(bgp_large_community, [(LOCAL_ASN, 120, *)]).len != 0 then bgp_large_community.add((LOCAL_ASN, 120, POP));
    if filter(bgp_large_community, [(LOCAL_ASN, 121, *)]).len != 0 then bgp_large_community.add((LOCAL_ASN, 121, REGION));
    if (LOCAL_ASN, 122, REGION) ~ bgp_large_community then bgp_large_community.add((LOCAL_ASN, 122, REGION));
    # ROUTE_DECIDER Start
    if (LOCAL_ASN, 110, 2) ~ bgp_large_community then bgp_local_pref = 500;
    else if (LOCAL_ASN, 110, 1) ~ bgp_large_community then bgp_local_pref = 400;
    else bgp_local_pref = 300;

    viaRegion = 0;
    # Route is via Europe & Africa & Middle East
    if bgp_large_community ~ [(LOCAL_ASN, 122, 100), (LOCAL_ASN, 122, 300..310), (LOCAL_ASN, 122, 600)] then viaRegion = viaRegion + 1;
    # Route is via America
    if bgp_large_community ~ [(LOCAL_ASN, 122, 200..299)] then viaRegion = viaRegion + 1;
    # Route is via East Asia & Oceania
    if bgp_large_community ~ [(LOCAL_ASN, 122, 400..500)] then viaRegion = viaRegion + 1;

    if viaRegion > 2 then reject;
    else if viaRegion = 2 then bgp_local_pref = bgp_local_pref - 50;
    else if viaRegion then bgp_local_pref = 0;

    # Route is via China mainland but not advertise in China mainland.
    if (LOCAL_ASN, 122, 430) ~ bgp_large_community && REGION != 430 && (LOCAL_ASN, 120, 430) ~ bgp_large_community then {
        reject;
    }

    bgp_local_pref = bgp_local_pref - filter(bgp_large_community, [(LOCAL_ASN, 122, *)]).len * 10;
};

function net186_export_filter (POPID) {
    if (65535, 65282) ~ bgp_community then {
        reject;
    }

    if (65535, 65283) ~ bgp_community then {
        if (POPID % 10) != (POP % 10) then {
            reject;
        }
    }
};