MPLS的配置问题

hyyh724886

ip vpn-instance beijing
route-distinguisher 65000:10
reserve-vlan 4001
vpn-target 65000:10100 65000:20100 65000:1020100 65000:2010100 65000:2030100 65000:1030100 65000:2090100 65000:2091100 import-extcommunity
vpn-target 65000:2040100 65000:1040100 65000:1010100 65000:1050100 65000:2050100 65000:1070100 65000:2070100 65000:1090100 import-extcommunity
vpn-target 65000:1091100 65000:1110100 65000:2110100 65000:1120100 65000:2120100 65000:1140100 65000:2140100 65000:1150100 import-extcommunity
vpn-target 65000:2150100 65000:1160100 65000:2160100 65000:1170100 65000:2170100 65000:1180100 65000:2180100 65000:1190100 import-extcommunity
vpn-target 65000:2190100 65000:1200100 65000:2200100 65000:2230100 65000:1240100 65000:2240100 65000:1250100 65000:2250100 import-extcommunity
vpn-target 65000:1260100 65000:2260100 65000:1270100 65000:2270100 65000:1230100 65000:1280100 65000:2280100 65000:1290100 import-extcommunity
vpn-target 65000:10100 export-extcommunity

这些都是什么意思？请大神讲解