Trong the gioi so hoa ngay nay, viec truy cap thong tin nhanh chong va khong bi gian doan la dieu vo cung quan trong. Tuy nhien, doi khi chung ta lai gap phai nhung rao can khong mong muon, vi du nhu khi mot trang web yeu thich hoac mot dich vu thiet yeu nao do dot ngot bi chan truy cap. Trong so nhung tinh huong do, viec truy cap vao mot dia chi cu the nhu 6623 (hoac bat ky dia chi nao khac gap van de tuong tu) bi chan co the gay ra nhieu phien toai.



May man thay, co mot giai phap ky thuat tuong doi don gian ma hau het nguoi dung may tinh deu co the thuc hien duoc: thay doi may chu DNS (Domain Name System). Bai viet nay se di sau vao ly do tai sao viec chan truy cap xay ra va quan trong hon, cung cap huong dan chi tiet, de hieu ve cach thuc hien viec doi DNS tren may tinh de ban co the tiep tuc ket noi voi the gioi truc tuyen ma khong gap tro ngai.



DNS La Gi va Tai Sao No Quan Trong Trong Viec Truy Cap Mang?



Truoc khi di vao phan "cach lam", chung ta can hieu ro DNS la gi. Hay tuong tuong DNS nhu mot cuon danh ba dien thoai khong lo cua Internet.



Khi ban go mot dia chi web (vi du: `www.google.com`) vao trinh duyet, may tinh cua ban khong the hieu ten do truc tiep. No can dia chi IP (mot chuoi so, vi du: `172.217.160.142`). Nhiem vu cua DNS la dich ten mien de nho do sang dia chi IP ma may chu co the nhan dien duoc.



May chu DNS mac dinh thuong la do nha cung cap dich vu Internet (ISP) cua ban cung cap. Day la diem mau chot: neu ISP chan truy cap vao mot ten mien cu the (nhu 6623), ho thuc hien dieu nay thong qua he thong DNS cua ho. Bang cach thay doi DNS, ban dang yeu cau may tinh cua minh su dung mot "cuon danh ba" khac, khong bi kiem soat boi ISP do.



Tai Sao Trang Web 6623 (Hoac Cac Trang Tuong Tu) Bi Chan?



Viec chan truy cap vao mot trang web cu the co the xuat phat tu nhieu nguyen nhan khac nhau, va 6623 (trong ngu canh nay, chung ta hieu la mot ten mien hoac mot cong truy cap cu the nao do dang gap van de) co the la nan nhan cua mot trong so chung:



1. Quy dinh cua Nha cung cap Dich vu (ISP Blocking): Day la ly do pho bien nhat. ISP co the chan truy cap dua tren yeu cau phap ly, chinh sach noi bo, hoac don gian la de quan ly luu luong truy cap.

2. Kiem duyet cua Chinh phu/Khu vuc: O mot so quoc gia hoac khu vuc, viec truy cap vao cac noi dung nhat dinh co the bi han che thong qua viec chan DNS.

3. Van de Ky thuat Tam thoi: Doi khi, may chu DNS cua ISP gap su co hoac cau hinh loi, dan den viec khong the phan giai dia chi cua trang web do mot cach chinh xac, tao cam giac nhu no da bi chan.



Viec thay doi DNS khong chi giup ban vuot qua cac rao can nay ma con co the cai thien toc do duyet web va tang cuong bao mat neu ban chon su dung cac may chu DNS cong cong uy tin.



Loi Ich Cua Viec Doi DNS Ngoai Viec Truy Cap 6623



Mac du muc tieu chinh cua chung ta la khac phuc su co voi 6623, viec chu dong doi DNS mang lai nhieu loi ich lau dai:



Tang Toc Do Phan Giai: Cac may chu DNS cong cong thuong duoc toi uu hoa rat tot, giup viec chuyen doi ten mien sang IP nhanh hon so voi DNS mac dinh cua ISP.

Bao Mat Tot Hon: Mot so dich vu DNS cung cap tinh nang loc ma doc, chong lua dao (phishing), giup bao ve may tinh cua ban.

* Vuot Qua Kiem Duyet: Cho phep ban truy cap cac noi dung bi chan tai dia phuong ma khong can dung den VPN phuc tap.



Cac May Chu DNS Cong Cong Pho Bien va Dang Tin Cay



Truoc khi bat dau qua trinh thay doi, ban can chon mot bo DNS moi. Duoi day la mot so lua chon hang dau ma cong dong cong nghe thuong tin dung, rat phu hop cho viec truy cap cac trang nhu 6623 ma khong gap tro ngai:



| Nha Cung Cap | Dia chi IPv4 Uu tien | Dia chi IPv4 Thay the |

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

| Google Public DNS | 8.8.8.8 | 8.8.4.4 |

| Cloudflare DNS | 1.1.1.1 | 1.0.0.1 |

| OpenDNS Home | 208.67.222.222 | 208.67.220.220 |



Luu y: Cloudflare (1.1.1.1) noi tieng ve toc do va cam ket bao mat quyen rieng tu cao, thuong la lua chon hang dau cho nhung ai can truy cap nhanh chong va on dinh.



Huong Dan Chi Tiet: Cach Doi DNS Tren Windows



Hau het nguoi dung may tinh ca nhan su dung he dieu hanh Windows. Quy trinh thay doi DNS duoc thuc hien thong qua Cai dat Mang. Hay lam theo cac buoc sau mot cach can than:



Buoc 1: Mo Cai dat Mang va Ket noi



1. Mo Bang dieu khien (Control Panel): Nhan to hop phim Windows + R, go `ncpa.cpl` va nhan Enter. Thao tac nay se mo truc tiep cua so "Network Connections".

2. Xac dinh Ket noi: Tim ket noi mang ban dang su dung. Neu ban dung Wi-Fi, do se la "Wi-Fi". Neu ban dung day mang, do se la "Ethernet".

3. Truy cap Thuoc tinh (Properties): Chuot phai vao ket noi dang hoat dong cua ban va chon "Properties" (Thuoc tinh).



Buoc 2: Chinh sua Cai dat IPv4



1. Trong cua so Properties, cuon xuong danh sach cac muc va tim "Internet Protocol Version 4 (TCP/IPv4)".

2. Chon muc nay, sau do nhan nut "Properties" nam ngay ben duoi.



Buoc 3: Nhap Dia chi DNS Moi



Trong cua so IPv4 Properties, ban se thay cac tuy chon DNS mac dinh (thuong la "Obtain DNS server address automatically").



1. Chon tuy chon "Use the following DNS server addresses" (Su dung cac dia chi may chu DNS sau).

2. Nhap DNS Uu tien: Tai o "Preferred DNS server", nhap dia chi DNS ban da chon (vi du: `1.1.1.1` neu ban chon Cloudflare).

3. Nhap DNS Thay the: Tai o "Alternate DNS server", nhap dia chi du phong (vi du: `1.0.0.1`).

4. Nhan "OK" de luu thay doi va dong cua so.



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



Sau khi thay doi DNS, he thong co the van dang luu tru thong tin phan giai cu trong bo nho dem (cache). De dam bao may tinh ngay lap tuc su dung may chu DNS moi de truy cap 6623, ban can xoa cache nay.



1. Mo Command Prompt (voi quyen Quan tri vien): Nhan phim Windows, go `cmd`, chuot phai vao "Command Prompt" va chon "Run as administrator".

2. Thuc hien lenh: Go lenh sau va nhan Enter:

```bash

ipconfig /flushdns

```

3. Ban se nhan duoc thong bao "Successfully flushed the DNS Resolver Cache."



Bay gio, hay thu truy cap lai 6623 hoac bat ky trang nao truoc day bi chan. Kha nang cao la ban se ket noi thanh cong nho vao may chu DNS moi.



Huong Dan Chi Tiet: Cach Doi DNS Tren macOS



Doi voi nguoi dung Apple, quy trinh cung kha truc quan thong qua Cai dat He thong (System Settings).



Buoc 1: Truy cap Cai dat Mang



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

2. Chon "System Settings" (tren cac phien ban macOS moi) hoac "System Preferences" (tren cac phien ban cu hon).

3. Chon "Network" (Mang).



Buoc 2: Cau hinh Chi tiet Ket noi



1. Chon loai ket noi ban dang dung (Wi-Fi hoac Ethernet) va nhap vao nut "Details" (Chi tiet) hoac bieu tuong "..." ben canh ket noi do.

2. Trong cua so hien ra, chon tab "DNS".



Buoc 3: Them May chu DNS Moi



1. Ban se thay danh sach cac may chu DNS hien tai (thuong la cua ISP).

2. Nhan vao nut dau cong (+) de them mot may chu DNS moi.

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

4. Nhan dau cong (+) lan nua de them may chu du phong (vi du: `8.8.4.4`).

5. Sau khi them xong, ban co the chon va xoa cac dia chi DNS cu cua ISP bang cach nhan dau tru (-).

6. Nhan "OK" hoac "Apply" de luu cau hinh.



Buoc 4: Lam moi Cache DNS tren macOS



Tren macOS, viec lam moi cache thuong tu dong xay ra, nhung de dam bao:



1. Mo Terminal (ban co the tim kiem trong Spotlight).

2. Nhap lenh lam moi cache (cu phap hoi khac tuy phien ban macOS, nhung lenh duoi day hoat dong cho hau het cac phien ban gan day):

```bash

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

```

3. Nhap mat khau dang nhap may Mac cua ban khi duoc yeu cau.



Tai Sao Cac Trang Nhu 6623 Can Duoc Truy Cap Thong Qua DNS Khac?



Trong boi canh ma thong tin la tai san quy gia, viec tiep can cac dich vu va trang web nhu 6623 (du noi dung cu the la gi) mot cach tu do la dieu can thiet cho nhieu nguoi dung. Cac nen tang cung cap dich vu DNS cong cong khong chi la giai phap ky thuat ma con la phuong tien ho tro nguoi dung duy tri quyen truy cap cua minh.



Khi mot trang web bi chan o cap do DNS, co nghia la cac yeu cau truy cap ban dau cua ban da bi "lac huong" boi may chu cua ISP. Bang cach chuyen sang cac nha cung cap DNS uy tin toan cau (nhu Cloudflare hay Google), ban dang chon mot duong dan phan giai khac, mot con duong it bi kiem soat hon, giup viec truy cap vao 6623 tro nen muot ma hon.



Dieu nay dac biet quan trong doi voi nhung nguoi lam viec tu xa, nghien cuu vien, hoac bat ky ai phu thuoc vao nguon thong tin nhat dinh ma khong the bi gian doan boi cac han che mang cuc bo.



Khac Phuc Su Co Neu Doi DNS Van Khong Hieu Qua



Trong mot so truong hop hiem hoi, viec thay doi DNS khong giai quyet duoc van de truy cap 6623. Dieu nay thuong xay ra khi viec chan khong chi dung lai o cap do DNS ma la chan o cap do sau hon (vi du: chan IP truc tiep, hoac su dung tuong lua cap do ung dung).



Neu ban da thu cac buoc tren ma van khong thanh cong, hay can nhac cac buoc sau:



1. Kiem tra Ket noi VPN/Proxy: Dam bao ban khong vo tinh bat VPN hoac Proxy nao dang ghi de len cau hinh DNS moi cua ban.

2. Thu cac Bo DNS Khac: Neu 1.1.1.1 khong hoat dong, hay thu 8.8.8.8, hoac nguoc lai. Doi khi mot nha cung cap co the dang gap su co voi mot dia chi IP cu the.

3. Xoa Cache Trinh Duyet: Doi khi trinh duyet web (Chrome, Firefox, Edge) tu luu tru ket qua phan giai DNS cu trong bo nho cache cua rieng no. Hay xoa cache va cookie cua trinh duyet.

4. Kiem tra Tuong Lua/Phan Mem Bao Mat: Phan mem diet virus hoac tuong lua ben thu ba doi khi co the chan ket noi. Hay tam thoi vo hieu hoa chung de kiem tra.



Tong Ket Ve Suc Manh Cua DNS Tuy Chinh



Viec hieu va lam chu cac thiet lap mang co ban nhu DNS la mot ky nang quy bau trong ky nguyen Internet. No trao cho ban quyen kiem soat nhieu hon doi voi trai nghiem truc tuyen cua minh. Neu ban dang gap kho khan trong viec truy cap 6623 hoac bat ky dich vu truc tuyen nao khac do bi chan DNS, viec chuyen sang su dung cac may chu DNS cong cong nhu Cloudflare hay Google la giai phap hieu qua, nhanh chong va mang lai nhieu loi ich ve hieu suat.



Hay thuc hien cac buoc huong dan tren mot cach can than, va ban se som lay lai duoc kha nang truy cap khong gioi han ma ban mong muon! The gioi Internet luon rong mo, va voi vai cu nhap chuot, ban hoan toan co the tu minh mo khoa nhung canh cua dang bi dong.

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