Overview
This article explains how to locate records or traffic management pools in an UltraDNS domain that contain a specific IPv4 or IPv6 address.
Searching for an address in an UltraDNS domain is different from performing a reverse DNS lookup. A reverse DNS lookup requests a PTR record. It does not identify every forward DNS record or UltraDNS pool that contains the address.
When to Use This Article
Use this article when:
- You know an IP address and need to locate a record or pool configured with that address in an UltraDNS domain.
- You need to identify which hostname in an UltraDNS domain is configured with a specific server address.
- You are looking for an
Arecord,AAAArecord, or traffic management pool that contains a specific IP address.
If you are trying to perform a reverse DNS lookup or host a PTR record in UltraDNS, refer to Host Reverse DNS PTR Records in UltraDNS.
Before You Begin
- You must have access to the UltraDNS domain that you want to search.
- To use the REST API, you must have valid UltraDNS API access and an authorization token.
- If you do not know the domain, identify the candidate UltraDNS domains that may contain the address. The documented portal search operates within one open domain.
Understand the Difference
Forward DNS maps a hostname to an IP address.
Example IPv4 record:
www.example.com. A 192.0.2.10
Example IPv6 record:
www.example.com. AAAA 2001:db8::10
Reverse DNS maps the reverse representation of an IP address to a hostname by using a PTR record.
Example IPv4 PTR record:
10.2.0.192.in-addr.arpa. PTR www.example.com.
A reverse DNS lookup requests the PTR RRSet published by the authoritative name servers for the applicable reverse DNS namespace. The response may contain no PTR record or one or more PTR targets.
A PTR response does not identify every hostname or DNS record that points to the address. Multiple A or AAAA records can contain the same IP address. DNS does not provide a query that lists every A or AAAA record whose record data contains a specified address.
Search for the IP Address in the UltraDNS Portal
The UltraDNS Portal search operates within the domain that is currently open.
- Log in to the UltraDNS Portal.
- Select Domains.
- Open the domain that may contain the IP address.
- Select the Records tab.
- Enter the complete IPv4 or IPv6 address in the Search Filter.
- Review the displayed records and pools.
- Open each applicable result and confirm that the record or pool configuration contains the address being located.
The Search Filter is documented as supporting a record or pool name, an IP address, or a TTL value.
For domains containing 5,000 records or fewer, Table View provides a compact list of the records and pools configured in the domain. Domains containing more than 5,000 records cannot use Table View.
The available portal documentation does not describe an account-wide IP-address search across every domain. If the domain is unknown, search each candidate domain separately.
Search Standard Records Using the REST API
The REST API can filter standard resource record RRSets in a specified zone by matching their rdata.
GET https://api.ultradns.com/zones/{zoneName}/rrsets?q=value:{IP-address}+kind:RECORDS
Example:
GET https://api.ultradns.com/zones/example.com/rrsets?q=value:192.0.2.10+kind:RECORDS
The value operator performs a partial match against the rdata of standard resource records. It does not perform an exact IP-address comparison.
Review each returned RRSet and confirm that:
- The record type is
Afor an IPv4 address orAAAAfor an IPv6 address. - The complete
rdatavalue represents the address being located.
IPv6 addresses can use compressed or expanded notation. Two differently formatted IPv6 values can represent the same address. Compare the complete IPv6 address value rather than relying only on identical text formatting.
The endpoint returns a maximum of 100 rows by default. Use the limit and offset parameters and review the returned resultInfo values when additional results are available.
The request applies to one specified zone. Repeat the request for each applicable UltraDNS zone.
Search Pools Using the REST API
The REST API value query operator applies only to standard RECORDS RRSets. The operator is ignored for pool RRSets and cannot perform a server-side search for an IP address contained in a pool.
Retrieve the pool RRSets for a specified zone with:
GET https://api.ultradns.com/zones/{zoneName}/rrsets?q=kind:POOLS
Review every returned pool for the IP address. Inspect the pool's rdata and any pool-specific profile data. An address can appear in a profile field instead of the primary rdata. For example, a Simple Failover backup address is returned in profile.backupRecord.rdata.
Confirm that the complete value represents the address being located. Review all pages when the returned resultInfo indicates that additional results are available.
The UltraDNS Portal search may be more convenient when searching pools interactively.
If You Only Have an IP Address
If you do not know the UltraDNS domain and only want to determine whether the address has a PTR record, run:
dig -x <IP-address>
The -x option performs a PTR lookup using the applicable IPv4 or IPv6 reverse DNS namespace.
A returned PTR target does not establish that it is the only hostname whose A or AAAA record contains the address.
If no PTR record is returned, that does not establish that no forward DNS records point to the address.
Expected Outcome
The portal search displays matching results from the selected UltraDNS domain. Review each result to confirm that the complete IP address is present in the record or pool configuration.
The API value filter returns partial rdata matches from standard records in the specified zone. Confirm the record type and complete address value, and review every page of results.
Pool RRSets must be retrieved and inspected because the API value filter does not search the contents of pools.
Neither method searches zones hosted by unrelated DNS providers or enumerates every public hostname that uses the address.