 May chu phan giai ten mien (DNS Server) la nhung may chu duoc cai dat, va cung cap dich vu phan giai ten mien DNS. May chu DNS duoc phan ra thanh 2 loai nhu sau :
Primary DNS Server (PDS) Primary DNS Server (PDS) la nguon xac thuc thong tin chinh thuc cho cac ten mien ma no duoc phep quan ly. Thong tin ve mot ten mien do PDS duoc phan cap quan ly thi duoc luu tru tai day va sau do co the duoc chuyen sang cac Secondary DNS Server (SDS). Cac ten mien do PDS quan ly thi duoc tao, va sua doi tai PDS va sau do duoc cap nhat den cac SDS . Secondary DNS Server (SDS) DNS duoc khuyen nghi nen su dung it nhat la hai DNS server de luu dia chi cho moi mot vung (zone). PDS quan ly cac vung va SDS duoc su dung de luu tru du phong cho vung, va cho ca PDS. SDS khong nhat thiet phai co nhung khuyen khich hay su dung . SDS duoc phep quan ly ten mien nhung du lieu ve ten mien khong phai duoc tao ra tu SDS ma duoc lay ve tu PDS. PDS co the cung cap cac hoat dong o che do khong tai tren mang. Khi luong truy van vung (zone) tang cao, PDS se chuyen bot tai sang SDS (qua trinh nay con duoc goi la can bang tai), hoac khi PDS bi su co thi SDS hoat dong thay the cho den khi PDS hoat dong tro lai . SDS thuong duoc su dung tai noi gan voi cac may tram (client) de co the phuc vu cho cac truy van mot cach de dang. Tuy nhien, cai dat SDS tren cung mot subnet hoac cung mot ket noi voi PDS la khong nen. Dieu do se la mot giai phap tot de du phong cho PDS, vi khi ket noi den PDS bi hong thi cung khong anh huong gi toi den SDS.
Ngoai ra, PDS luon duy tri mot luong lon du lieu va thuong xuyen thay doi hoac them cac dia chi moi vao cac vung. Do do, DNS server su dung mot co che cho phep chuyen cac thong tin tu PDS sang SDS va luu giu tren dia. Khi can phuc hoi du lieuve cac vung, chung ta co the su dung giai phap lay toan bo ( full ) hoac chi lay phan thay doi (incrememtal). Article source http://w4rum.com/181.t
| 