Frequently Asked Questions (& Answers)

Can you tell me more about your nameservers?

We have a number of DNS servers spread across the globe. Read more about our nameservers.

I've changed my records... Why aren't the effects immediate?

Unlike so many things in the digital era, DNS updates are NOT immediate.

Caching and Time to Live (TTL) mean changes in DNS records will take time to propagate. Resolvers can use their cached responses and don't have to do a full DNS lookup for every request: this results in faster response with considerably less stress on the overall internet and greatly reduced impact of brief DNS server outages.

If you do not need to change your DNS records very often and can plan any updates well in advance, it is best practice to have a relatively high TTL (particularly if you already have redundancy through the use of multiple A records and MX records with different destinations). Just reduce the TTL to a short period well before the update (so the short TTL is in effect during the update), change the records, test, and once things are verified, change the TTLs back to the longer TTL.

Do you have an API?

Yes. Domains, Hosts, and Templates are all supported by a full REST API. See the REST API documentation for details. For very basic updates, we also support dynamic DNS updates. More information is below.

Are the Zone Serial Number values used by Zerigo RFC1912 compliant?


Do you support wildcards?

Sure do. Just use '*' for the hostname. By default our name servers will check for an actual host record with the queried name. If that's not present, then it checks for a wildcard record. That means you can effectively use a wildcard record as a catchall.

I'm trying to add a DNS record containing backslash characters, but the system responds as "Data Invalid"

Replace any backslash characters with %5C. Our forms see backslashes as escape/control characters.

Example: "Backslashes\Work!" would be entered as "Backslashes%5CWork!"

Do you support email forwarding?

Zerigo does not offer email forwarding. We do, of course, support just about any possible email configuration via third-party email providers. One popular solution to email forwarding is to use a Google Apps For Your Domain account (which will even let you mix-and-match regular and forwarding addresses).

Do you support web forwarding or redirects?

Yes. Create a DNS host record using our special "Redirect" type. By default, web redirects use HTTP 302 redirects. This may be changed to a 301 redirect or a cloaked redirect under DNS -> Preferences.

Can I use other providers such as DME or Dyn as a slave to my master DNS zone at Zerigo?

Yes, this provides an excellent way to distribute your DNS service across multiple providers to achieve maximum fault tolerance for your DNS infrastructure. We recommend running your master zone at Zerigo so you can take advantage of our rich DNS management features and API integration. Slave zones can be easily and economically established from other providers. Please be aware that GeoDNS & Redirect record support are unsupported in these configurations since they depend on DNS features which are specific to Zerigo.

To setup an external slave for a specific zone please see the instructions below:

1) Set your service type to Master With Slave Support

2) Add your external name servers in the nameserver settings in addition to the zerigo servers

I'm using Zerigo for Slave DNS only. What IP addresses do I need to allow AXFR updates from?

Zerigo uses two hidden slaves to make AXFR requests for zone data from your master nameserver. You should use one or more of our Standard nameservers to actually answer your domain's queries. Do not add these servers to your domain's settings at your registrar.

AXFR isn't working. My slave DNS servers are not being updated when I make changes to my zone in the portal, how can I fix this?

A large percentage of our support requests related to AXFR issues have to do with firewall problems. If you have a firewall protecting your slave DNS servers please make sure that you have both TCP & UDP port 53 open. TCP port 53 is particularly important since it's used for AXFR.

Do you offer domain registration?

No, we are not a domain registrar. We provide DNS services for domains that you've already registered elsewhere.

How do I setup vanity (custom) nameservers?

All the details are documented here: setting up vanity nameservers.

How do I configure a reverse domain?

All the details are documented here: Detailed Reverse DNS FAQ.

How do I add third and fourth level domains?

The hostname field allows nested subdomains. For example, if your domain is '' and the hostname field is 'www.dealers', then the full, valid domain name would be ''. You can have even more levels if necessary.

How do I setup round-robin records?

Simply add multiple records. Our system will automatically detect this situation and rotate through the possible responses. For example, create two host records, each with Hostname: www and Type: A, but give them different IPs. Everything else is automatic.

Do you support SPF or Domain Keys records?

Absolutely. Domain Keys records should be entered using a TXT record type.

SPF records may be entered with the dedicated SPF record type or, for legacy compatibility, with a TXT record. You may create both for maximum compatibility.

What's the status of IPv6 support?

We provide full IPv6 support. Our nameservers have native IPv4 and IPv6 connectivity. We also support AAAA records for full lookups as well as reverse domains (

Do you support NS subdomain delegation?

Yes, simply add new host records with the NS type.

What is static DNS service?

Static DNS service is DNS service for static, or consistent, IP addresses. This is by far the most common DNS service—used for pretty much every service (web, email, etc.) across the internet.

What is dynamic DNS service?

Dynamic DNS service is DNS service for dynamic, or changing, IP addresses. Some individuals and small businesses want to run some kind of low-use internet service from their DSL, cable, or other internet connection. The IP address for these connections changes periodically—sometimes every few months, sometimes every few hours or even more often.

If an IP address changes infrequently, it's not too bad to just change the DNS entry—if the TTL (time-to-live) for that address is short (15 minutes or less). Zerigo DNS allows TTLs as low as 1 minute to support this.

For IP addresses that change more often, and sometimes even for those that change infrequently, some kind of software program is run from the target computer that publishes its current IP address—so the update is automatic and timely. Zerigo DNS is capable of receiving this notification and updating the appropriate DNS entry accordingly.

How are dynamic updates made?

There are two options for making changes to your DNS service without using our web interface. The first is dynamic updates. This is ideal for simple dynamic DNS service. See the Dynamic Updates documentation for details and examples. The second option is our full-featured REST API.

Can I use IPv6 addresses with dynamic updates?

Yes. Our system will automatically look for an AAAA record to update either when accessed via an IPv6 address (and no IP address is specified) or when expressly provided with an IPv6 address.

Comments, complaints, suggestions

We're very interested in your feedback—positive or negative. Does it work well for you? Is something broken, confusing, or hard to use? Is something you're looking for missing? We'd like to hear about all of it. Contact us.