# DNS 1-Page Cheat Sheet

> Domain naam se IP tak ka safar, nameserver, A / CNAME / MX / TXT records aur TTL: seedhi Hinglish mein, MDN aur Cloudflare Docs ke hisaab se

Free guide by bloopcommits (@bloopcommits) · https://bloopcommits.pages.dev/dns/

Website ka naam yaad rehta hai, par computer ko number chahiye. DNS wahi system hai jo naam ko number mein badalta hai. Is page mein DNS ki saari basic cheezein ek jagah hain: lookup kaise hota hai, nameserver kya hai, A aur CNAME record mein kya fark hai, TTL kya hota hai, aur domain ko hosting se jodte waqt kya karna hai. Har baat MDN Web Docs ya Cloudflare Docs ke apne page ke hisaab se hai; jo humari apni salaah hai, wo alag likhi hai.

> **Pehle ye padho**
>
> - Ye samjhane ke liye banaya gaya cheat sheet hai. Tumhare domain ke asli records tumhare provider ke panel mein hote hain: kuch bhi badalne se pehle wahi dekho.
> - Is page ke saare example naam ".example" wale hain aur saare IP 192.0.2.x wale hain (documentation ke liye reserved address). Inhe apne asli domain mein mat daalo.
> - Kitna time lagega ye TTL aur provider par depend karta hai: koi pakka ghanta (jaise "24-48 ghante") hum nahi bolte.

## Lookup kaise hota hai (MDN ke hisaab se)

1. Tum browser ki address bar mein naam type karte ho, jaise mozilla.org.
2. Computer pehle apni local DNS cache mein dekhta hai ki is naam ka IP pehle se yaad hai ya nahi. Mil gaya to browser seedha web server se baat shuru kar deta hai: "End of story".
3. Nahi mila to computer DNS server se poochta hai. MDN ke shabdon mein DNS server ka kaam "precisely" yehi hai: batana ki kis registered domain name ke peeche kaunsa IP address hai.
4. IP mil gaya, ab browser us IP wale web server se website ki files maangta hai.

## Do shabd jo har jagah milenge

| Shabd | Seedhi bhaasha mein | Source |
| --- | --- | --- |
| DNS | Domain Name System: human-readable domain naam ko IP address mein "translate" karne wala system. | Cloudflare Docs: Concepts |
| Nameserver | Wo server jahan tumhare domain ke asli DNS records rakhe hote hain. Cloudflare Docs: authoritative nameservers "the definitive DNS records" rakhte hain aur final jawab dete hain. | Cloudflare Docs: Concepts |
| DNS record | Authoritative DNS servers par rakhi "instructions": kaun sa naam kahan point karega. | Cloudflare Docs: Concepts |
| Cache | Kisi jawab ko kuch der yaad rakhna, taaki har baar poochna na pade. | MDN: What is a domain name |

## Records: kaun sa kya karta hai (Cloudflare Docs: DNS record types)

| Record | Kya karta hai | Example (banaya hua) |
| --- | --- | --- |
| A / AAAA | Naam ko ek ya zyada IPv4 (A) ya IPv6 (AAAA) address se jodta hai. | blog.meri-site.example → 192.0.2.1 |
| CNAME | Naam ko doosre (canonical) naam se jodta hai: IP nahi, doosra naam batata hai. Cloudflare Docs: proxy ke saath final naam ka ek valid A ya AAAA record hona chahiye. | www.meri-site.example → blog.meri-site.example |
| MX | Email kis mail server par jayegi: "A mail exchange (MX) record is required to deliver email to a mail server." | mail.meri-site.example (priority ke saath) |
| TXT | "A text (TXT) record lets you enter text into the DNS system": verification jaisi cheezein is mein aati hain. | koi verification text |

## TTL: cache kitni der yaad rakhe

Cloudflare Docs ke hisaab se TTL ek field hai jo "controls how long each record is cached". Isliye record badalne ke baad sab jagah naya jawab ek saath nahi dikhta: koi laptop ya server purana jawab TTL khatam hone tak yaad rakh sakta hai. Cloudflare ke apne dashboard mein "Auto" ka matlab 300 second (paanch minute) hai, aur sirf-DNS records ke liye wo 60 second (non-Enterprise) se 1 din ke beech ka TTL chunne dete hain. Ye Cloudflare ke numbers hain: doosre provider ke alag ho sakte hain.

## Domain ko hosting se jodna: 5 kadam (humari salaah)

1. Hosting wale ke dashboard mein dekho ki wo kya maang raha hai: nameserver (jaise ns1... ns2...) ya koi A / CNAME record.
2. Kuch bhi badalne se pehle apne domain ke purane DNS records ka screenshot le lo (A, CNAME, MX, TXT sab). Email ka MX / TXT galti se hat gaya to email ruk sakti hai.
3. Domain jahan khareeda hai wahan ke panel mein "Nameservers" ya "DNS records" wala section kholo.
4. Hosting wale ke bataye naam / values bilkul waise hi daalo aur save karo.
5. Phir intezaar: TTL aur provider ke hisaab se kuch minute se zyada bhi lag sakta hai. Site khulne tak baar baar naye records mat badlo.

> **Nameserver badalna = control badalna**
>
> - Jab tum nameserver naye provider ke par karte ho, to tumhare domain ke records ka control ab usi naye provider ke paas hota hai. Purane provider ke records ka naye par apne aap aana zaroori nahi.
> - Isliye pehle naye provider mein purane saare records (khaaskar MX aur TXT) dobara bana lo, phir nameserver badlo.

## Aam galtiyan

- Records badalne ke turant baad "kaam nahi kar raha" soch kar phir badal dena: cache purana jawab yaad rakh sakta hai.
- Nameserver badal diya par email ke MX / TXT records naye provider mein nahi banaye.
- A record mein IP ki jagah naam likh dena, ya CNAME mein IP likh dena: A mein IP, CNAME mein naam.
- Screenshot liye bina records mita dena.
- "24-48 ghante lagte hain" jaisi baat ko pakka maan lena: ye TTL aur provider par depend karta hai.

> **Yaad rakho**
>
> - DNS = naam ko IP mein badalne wala system. Lookup: pehle cache, phir DNS server, phir web server.
> - Nameserver = asli records ka ghar. A = naam to IP. CNAME = naam to doosra naam. TTL = cache kitni der yaad rakhe.
> - Kuch bhi badalne se pehle purane records ka screenshot. Kitna time lagega, TTL aur provider par depend karta hai.

## Official links

- [MDN Web Docs: What is a domain name?](https://developer.mozilla.org/en-US/docs/Learn_web_development/Howto/Web_mechanics/What_is_a_domain_name)
- [Cloudflare Docs: DNS concepts](https://developers.cloudflare.com/dns/concepts/)
- [Cloudflare Docs: DNS record types](https://developers.cloudflare.com/dns/manage-dns-records/reference/dns-record-types/)
- [Cloudflare Docs: Time to Live (TTL)](https://developers.cloudflare.com/dns/manage-dns-records/reference/ttl/)

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