Chao cac ban, nhung nguoi dam me kham pha the gioi so! Chac han khong it lan chung ta cam thay "kho chiu" khi dang luot web, lam viec hay giai tri ma dot nhien truy cap vao mot trang web yeu thich, dac biet la nhung dia chi co ve quen thuoc nhu 6623, lai gap phai thong bao chan truy cap. Cam giac nay that su phien toai, giong nhu dang di tren mot con duong dep bong nhien gap phai rao chan bat ngo vay!



Nhung dung lo lang qua, vi hom nay chung ta se cung nhau "pha tan" rao can do mot cach nhanh chong va hieu qua nhat. Bai viet nay se la tam ban do chi tiet giup ban lam chu ket noi mang cua minh bang cach doi DNS (Domain Name System), dac biet trong nhung truong hop truy cap vao cac trang web nhu 6623 bi han che.



Chung ta se di sau vao ban chat cua DNS la gi, tai sao no lai bi chan, va quan trong nhat la cac buoc thuc hien chi tiet tren ca Windows va macOS. Hay san sang de lay lai quyen tu do luot web cua minh nhe!



DNS La Gi? Tai Sao No Lai Quan Trong Den Vay?



Truoc khi di vao phan ky thuat "hack nao" la doi DNS, chung ta can hieu ro "linh hon" cua Internet nay la gi da. Hay hinh dung the nay:



Internet la mot thanh pho khong lo voi hang ty ngoi nha (trang web). Moi ngoi nha deu co mot dia chi cu the (Dia chi IP, vi du: `192.168.1.1`). Tuy nhien, con nguoi chung ta khong ai thich nho nhung day so phuc tap nhu vay ca. Thay vao do, chung ta dung ten de nho hon, vi du nhu "6623" (du thuc te ten mien se dai hon, nhung tam goi chung nhu vay de de hinh dung).



DNS (Domain Name System) chinh la cuon danh ba dien thoai khong lo cua Internet. Khi ban go mot ten mien (nhu 6623) vao trinh duyet, he thong DNS se thuc hien nhiem vu phien dich ten mien do thanh dia chi IP tuong ung de may tinh cua ban tim den dung "ngoi nha" can vao.



Van De Cua DNS Mac Dinh



Cac nha cung cap dich vu Internet (ISP) ma ban dang su dung thuong mac dinh gan cho ban mot may chu DNS rieng cua ho. May chu nay hoat dong tot cho cac truy cap thong thuong.



Tuy nhien, khi mot trang web nao do (vi du nhu 6623) bi cac co quan quan ly yeu cau chan truy cap, dieu dau tien ho lam la ra lenh cho cac may chu DNS cua ISP ngung dich vu tra cuu ten mien do. Khi ban go 6623, may chu DNS cua ISP se tra ve mot thong bao loi hoac chuyen huong ban den mot trang thong bao chan. Ket qua la: Ban khong vao duoc trang web.



Day chinh la luc ky nang doi DNS tro thanh "chia khoa van nang"!



Vi Sao Doi DNS La Giai Phap Tuyet Voi Khi 6623 Bi Chan?



Khi ban doi DNS, ban dang quyet dinh "khong dung cuon danh ba cua ISP nua" ma thay vao do, ban se dung mot cuon danh ba khac dang tin cay va khong bi can thiep boi lenh chan cuc bo.



Viec doi sang cac may chu DNS cong cong uy tin (nhu Google Public DNS, Cloudflare 1.1.1.1, hay OpenDNS) mang lai nhieu loi ich vuot troi:



1. Vuot qua Chan Dia Ly/Loc Noi Dung: Day la muc dich chinh. Cac may chu DNS cong cong thuong khong bi ap dat cac quy tac chan tuong tu nhu ISP dia phuong cua ban. Khi may chu DNS moi dich dia chi 6623 thanh IP chinh xac, duong truyen cua ban se duoc thiet lap thanh cong.

2. Tang Toc Do Truy Cap: Nhieu may chu DNS cong cong duoc toi uu hoa cao, giup viec tra cuu ten mien nhanh hon dang ke, dan den thoi gian tai trang duoc cai thien.

3. Bao Mat va Rieng Tu Tot Hon: Cac dich vu DNS uy tin thuong cam ket khong luu tru lich su truy cap cua ban (dac biet la cac dich vu tap trung vao quyen rieng tu nhu Cloudflare 1.1.1.1).



Noi tom lai: Doi voi nhung noi dung ban quan tam va truy cap thuong xuyen nhu cac nen tang thong tin hoac giai tri (nhu 6623 co the la mot trong so do), viec chu dong thay doi DNS la cach nhanh nhat, an toan nhat va lau dai nhat de dam bao trai nghiem luot web lien mach.



Cac "Chiec Chia Khoa Vang": Nhung Bo DNS Thay The Pho Bien Nhat



Truoc khi thuc hanh, chung ta can co nhung "chia khoa" tot nhat. Duoi day la ba bo DNS duoc cong dong tin dung nhat hien nay:



| Nha Cung Cap | Dia chi IPv4 Chinh | Dia chi IPv4 Phu | Uu Diem Noi Bat |

| :--- | :--- | :--- | :--- |

| Cloudflare (Uu tien toc do & rieng tu) | `1.1.1.1` | `1.0.0.1` | Cuc nhanh, bao mat manh. |

| Google Public DNS | `8.8.8.8` | `8.8.4.4` | Pho bien, on dinh, do phu song rong. |

| OpenDNS Home | `208.67.222.222` | `208.67.220.220` | Cung cap kha nang loc noi dung cho phu huynh (neu can). |



Ban chi can chon mot bo trong so nay de bat dau qua trinh thay doi.



Huong Dan Chi Tiet Cach Doi DNS Tren Windows (Phien Ban Moi Nhat)



Thao tac tren Windows thuong duoc thuc hien thong qua giao dien cai dat mang. Dung lo, no rat truc quan!



Buoc 1: Mo Cai Dat Mang



1. Nhan to hop phim Windows + I de mo ung dung Settings (Cai dat).

2. Chon Network & Internet (Mang & Internet).

3. O cot ben trai, chon loai ket noi ban dang dung (thuong la Wi-Fi hoac Ethernet).

4. Ben phai, nhap vao Properties (Thuoc tinh) cua ket noi dang hoat dong.



Buoc 2: Truy Cap Cai Dat DNS



1. Trong cua so Properties, cuon xuong cho den khi ban thay muc IP settings (hoac DNS server assignment).

2. Nhan vao nut Edit (Chinh sua).

3. Trong cua so tha xuong, thay doi tu Automatic (DHCP) sang Manual (Thu cong).

4. Bat cong tac cho IPv4.



Buoc 3: Nhap Dia Chi DNS Moi



1. Tai o Preferred DNS (DNS Uu tien), nhap dia chi DNS chinh ma ban da chon (vi du: `1.1.1.1` neu chon Cloudflare).

2. Tai o Alternate DNS (DNS Thay the), nhap dia chi phu (vi du: `1.0.0.1`).

3. Quan trong: O cuoi cung, dam bao ban chon "Prefer IPv4 over IPv6" neu co tuy chon, hoac don gian la bo qua phan IPv6 neu ban chi nhap IPv4 (thuong la du cho viec chan truy cap).

4. Nhan Save (Luu).



Buoc 4: Xoa Bo Nho Cache DNS (Rat Quan Trong!)



Sau khi thay doi cai dat, may tinh cua ban van co the dang "nho" dia chi DNS cu. De buoc he thong cap nhat ngay lap tuc (de truy cap 6623 khong con bi chan):



1. Mo Command Prompt (CMD) voi quyen Administrator (Tim kiem CMD, chuot phai va chon "Run as administrator").

2. Go lenh sau va nhan Enter:

```bash

ipconfig /flushdns

```

3. Ban se thay thong bao "Successfully flushed the DNS Resolver Cache." (Da xoa bo nho dem DNS thanh cong).

4. Khoi dong lai trinh duyet (hoac tot hon la khoi dong lai may tinh) va thu truy cap lai trang web ban muon. Neu moi thu suon se, 6623 se hien ra!



Huong Dan Chi Tiet Cach Doi DNS Tren macOS (MacBook/iMac)



Tren he dieu hanh macOS, viec thay doi duoc thuc hien trong phan Tuy chon Mang.



Buoc 1: Mo Tuy Chon Mang



1. Nhap vao bieu tuong Apple o goc tren ben trai man hinh.

2. Chon System Settings (Cai dat He thong) (hoac System Preferences tren cac phien ban cu hon).

3. Tim va chon Network (Mang).



Buoc 2: Cau Hinh Ket Noi Mang



1. Chon ket noi mang ban dang su dung (Wi-Fi hoac Ethernet) o thanh ben trai.

2. Nhap vao nut Details (Chi tiet) hoac Advanced (Nang cao) (tuy phien ban macOS).

3. Chuyen sang tab DNS.



Buoc 3: Them May Chu DNS Moi



1. Trong muc DNS Servers, ban se thay danh sach cac may chu DNS hien tai.

2. Nhan vao dau + (dau cong) o phia duoi danh sach de them mot may chu moi.

3. Nhap dia chi DNS Uu tien (vi du: `8.8.8.8`).

4. Nhan + lan nua de them dia chi DNS Thay the (vi du: `8.8.4.4`).

5. Quan trong: Sau khi them xong, ban nen keo cac dia chi DNS moi len dau danh sach de dam bao chung duoc uu tien su dung.

6. Nhan OK hoac Apply (Ap dung) de luu thay doi.



Buoc 4: Cap Nhat Bo Nho Cache DNS tren macOS



macOS thuong cap nhat nhanh hon Windows, nhung de chac chan, ban co the thuc hien lenh sau trong Terminal (Tim kiem Terminal trong Spotlight):



1. Go lenh sau va nhan Enter (ban se can nhap mat khau dang nhap may):

```bash

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

```

2. Nhan Enter, nhap mat khau va Enter lan nua. He thong se xac nhan viec lam moi bo nho cache.



Bay gio, moi rao can DNS de truy cap 6623 da duoc go bo!



Doi DNS Qua Router: Giai Phap Toan Dien Cho Moi Thiet Bi



Viec thay doi DNS tren tung may tinh (Windows/Mac) rat hieu qua, nhung neu ban co nhieu thiet bi (dien thoai, may tinh bang, TV thong minh) ma van muon truy cap cac trang nhu 6623 ma khong can cau hinh lai lien tuc, co mot giai phap "thong minh" hon: Doi DNS truc tiep tren Router (Bo dinh tuyen) cua ban.



Khi ban thay doi DNS tren Router, moi thiet bi ket noi vao mang Wi-Fi do se tu dong su dung DNS moi ma ban da thiet lap.



Cac Buoc Tong Quan De Doi DNS Tren Router



Luu y: Giao dien Router rat da dang tuy thuoc vao hang san xuat (TP-Link, Linksys, Asus, Viettel, VNPT...), nhung quy trinh co ban la giong nhau:



1. Dang nhap vao Router: Mo trinh duyet va go dia chi IP Gateway cua Router (thuong la `192.168.1.1` hoac `192.168.0.1`). Nhap ten nguoi dung va mat khau (thuong la `admin/admin` neu chua doi).

2. Tim Muc Cai Dat WAN/Internet: Trong giao dien quan tri, tim den muc Internet Settings, WAN, hoac Network.

3. Tim Cai Dat DNS: Trong phan cai dat WAN, tim muc DNS Settings.

4. Chuyen sang Thu Cong: Thay doi che do tu "Get Automatically from ISP" sang "Use These DNS Servers" (Su dung may chu DNS nay).

5. Nhap Dia Chi: Nhap dia chi DNS Uu tien va Thay the (vi du: 1.1.1.1 va 1.0.0.1).

6. Luu va Khoi Dong Lai: Luu cau hinh va chon tuy chon khoi dong lai Router (Reboot).



Sau khi Router khoi dong lai, toan bo mang nha ban da duoc "nang cap" kha nang truy cap, giup viec ket noi den 6623 va cac dich vu khac tro nen de dang hon bao gio het.



Loi Ket: Lam Chu Ket Noi Cua Ban



Viec truy cap Internet bi gian doan do cac rao can ky thuat la dieu khong ai mong muon. Tuy nhien, voi kien thuc ve cach doi DNS, ban da co trong tay mot cong cu manh me de giai quyet van de nay mot cach nhanh chong va triet de.



Viec chuyen doi sang cac may chu DNS cong cong, dac biet la khi ban dang gap kho khan truy cap nhung trang web ban can (nhu 6623), khong chi giup ban "mo khoa" noi dung ma con cai thien toc do va bao mat cho trai nghiem truc tuyen tong the.



Hay manh dan thuc hanh cac buoc tren, va ban se thay the gioi Internet rong lon hon rat nhieu! Chuc ban luon co nhung gio phut luot web, lam viec va giai tri khong bi gian doan!

Xem them: cach doi dns tren may tinh khi 6623 bi chan