To fix DNS issues for your domain, work through the causes in order: check that the domain is registered and not expired, confirm it uses the right nameservers, check that the A, CNAME and MX records point to the right places, then allow for propagation and clear cached results. Most DNS problems come from one of these few causes, and you can find which one with free lookup tools before changing anything.
How DNS works, briefly
DNS (the Domain Name System) turns a domain name such as yourbusiness.co.zw into the IP address of the server that hosts it. When someone visits your site, their device asks a DNS resolver, which finds the domain’s authoritative nameservers and reads the records stored there. Results are cached for a time set by each record’s TTL (time to live). For background, see what a domain name is.
Common symptoms
- The browser shows “This site can’t be reached” or “DNS_PROBE_FINISHED_NXDOMAIN”.
- The site loads for some people but not others.
- The old website still appears after moving to a new host.
- The site works with www but not without it, or the other way round.
- Email stops arriving, or bounces, while the website still works.
Step 1: Check the domain is active
Log in to your registrar account and check the expiry date. An expired domain stops resolving. You can also run a WHOIS lookup and check the domain status. A status such as “clientHold” or “serverHold” means the registry has suspended the domain, often because of non-payment or a verification problem, and only the registrar can lift it.
Step 2: Check the nameservers
Nameservers decide which provider’s DNS records are used. If your domain points to your old host’s nameservers, any change you make at your new host has no effect.
- Find the nameservers your hosting or DNS provider told you to use.
- Look up the domain’s current nameservers with a WHOIS or DNS lookup tool.
- If they differ, update them at your registrar.
Edit records only at the provider your nameservers point to. Records stored anywhere else are ignored.
Step 3: Check the DNS records
You can look up records from your own computer:
- Windows: open Command Prompt and run nslookup yourdomain.com
- macOS or Linux: open Terminal and run dig yourdomain.com A, or dig yourdomain.com MX for mail records.
Online DNS checkers show the same results from many locations at once. Check these records:
A and AAAA records
The A record for your main domain should hold your web server’s IPv4 address. An AAAA record holds an IPv6 address. If an old AAAA record still points to a previous host, some visitors will reach the wrong server. Delete it or correct it.
The www record
www is a separate name. It needs its own A record or a CNAME pointing to the main domain. If it is missing, www.yourdomain.com will fail even when the main domain works.
CNAME records
A CNAME points one name to another name. A name with a CNAME cannot have any other records. That is why you normally cannot put a CNAME on the bare domain, which needs NS and SOA records. Some DNS providers offer a workaround called CNAME flattening.
MX records
MX records tell other mail servers where to deliver your email. If they point to the wrong server, or were missed when you changed nameservers, email fails while the website keeps working. Check that the MX target exists and has its own A record.
TXT records for email
SPF, DKIM and DMARC records are TXT records. A domain must have only one SPF record. Two separate SPF records cause SPF checks to fail, which can send your mail to spam.
Step 4: Allow for propagation
DNS changes are not instant everywhere. Resolvers keep cached answers until the old record’s TTL runs out. Record changes often show within minutes to a few hours. Nameserver changes can take up to 24 to 48 hours. To make future changes faster, lower the TTL a day before you plan to change a record. Our Help Centre explains how long DNS propagation takes.
Step 5: Clear cached results
Your own computer and browser may keep an old answer after the change has spread elsewhere:
- Windows: run ipconfig /flushdns in Command Prompt.
- macOS: run sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder in Terminal.
- Linux with systemd-resolved: run resolvectl flush-caches.
Then restart the browser, or test on a phone using mobile data instead of office Wi-Fi.
Step 6: Check DNSSEC
DNSSEC adds digital signatures to DNS records. If DNSSEC was turned on with your old DNS provider and you change nameservers without removing the old DS record at the registrar, resolvers that check DNSSEC will refuse to answer. The domain then fails for many users. Remove the old DS record, or set up DNSSEC again with the new provider.
Step 7: Check for proxy or CDN problems
If you use Cloudflare or another proxy, a record set to “proxied” sends traffic through that network. Website records can be proxied. Mail server records must not be, or email will fail. If the site shows a proxy error page, the problem is often between the proxy and your server, not in DNS itself.
When to ask for help
If records look right, propagation time has passed and the problem remains, contact your DNS or hosting provider. Give them the domain, the exact error, when it started and what you have changed. Tremhost customers can follow the guide to editing DNS records or contact support by ticket or WhatsApp, Monday to Friday, 08:00 to 17:00 CAT.
Frequently asked questions
Why does my site work for me but not for others?
Different resolvers cache records for different times. During propagation, some people see the new record and some see the old one. It settles once old TTLs expire.
Why is my website working but email is not?
The website uses A records and email uses MX records. Check that the MX records exist, point to the correct mail server and were copied over when you changed nameservers.
How do I check if my domain has expired?
Log in to your registrar account, or run a WHOIS lookup and check the expiry date and status.
Can a DNS problem be caused by an attack?
Yes, though it is less common than configuration mistakes. DDoS attacks on DNS providers or a hijacked registrar account can stop a domain resolving. Use MFA on your registrar account.
Next step
If you want your domain and DNS managed in the same place as your hosting, see Tremhost domain registration, with .co.zw from $6.99 a year and .com at $15.99 a year.
