# ISC DNS Checker

> Tests recursive DNS servers for DNS protocol specification conformance. (iPhone/iPad app by Internet Systems Consortium, Inc..)

- Source: https://appshunter.io/ios/app/isc-dns-checker/id1141834002 (this page in markdown: same URL + `.md`)
- Developer: [Internet Systems Consortium, Inc.](https://appshunter.io/developer/1115648879)
- Category: Utilities
- Price: Free
- Rating: 3.00/5 from 1 App Store ratings · 2 written reviews indexed
- Age rating: 4+
- Requires: iOS 9.0 · 19 MB
- Languages: English
- Released: 2017-02-10
- Data updated: 2026-06-25
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/isc-dns-checker/id1141834002/reviews.md

## What is ISC DNS Checker?

Deployment of important new DNS features such as DNSSEC relies on end users having access to DNS resolvers which behave correctly per the specifications.

This app, from ISC Research, tests recursive DNS servers for conformance against current DNS protocol specifications, especially with regard to EDNS(0) as specified in RFC 6891.

The app can automatically detect the DNS servers automatically discovered by your iOS device, or you can enter IP addresses to be tested manually.  Both IPv4 and IPv6 are supported.

Please send comments and questions to bind-users@lists.isc.org (email list subscription required)

## Key features

- Tests DNSSEC compliance
- Tests EDNS(0) conformance
- Automatic DNS server detection
- Manual IP address input
- IPv4 and IPv6 support

## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/isc-dns-checker/id1141834002/reviews.md

### 2/5 — App needs a bug fix

*2019-10-18*

Seems to be a useful app, unfortunately it crashes when it starts. Most likely needs to be updated for iOS 13.x

### 3/5 — Breaks on iOS 13

*2019-10-03*

This is a good utility, very handy for those cases where you need it. But it’s broken on iOS 13, crashing on start-up.

## Frequently asked questions about ISC DNS Checker

### What is ISC DNS Checker used for?

ISC DNS Checker is used to test recursive DNS servers for their conformance to current DNS protocol specifications, with a focus on EDNS(0) as defined in RFC 6891. It helps ensure DNS resolvers are behaving correctly.

### Does ISC DNS Checker support both IPv4 and IPv6?

Yes, ISC DNS Checker supports both IPv4 and IPv6 protocols for testing DNS servers. You can test servers using either address family.

### Can I manually enter DNS server IP addresses in ISC DNS Checker?

Yes, in addition to automatically detecting your device's DNS servers, ISC DNS Checker allows you to manually enter IP addresses for testing. This provides flexibility in choosing which servers to evaluate.

### What is the rating for ISC DNS Checker?

ISC DNS Checker has a rating of 3.0 stars based on 1 rating. This indicates a mixed reception from its current user base.

### Is ISC DNS Checker free to use?

Yes, ISC DNS Checker is available for free. There are no costs associated with downloading or using its core features.

### What devices is ISC DNS Checker compatible with?

ISC DNS Checker is compatible with iPhone, iPad, and iPod devices. It is designed for the iOS ecosystem.

### When was ISC DNS Checker last updated?

The latest version of ISC DNS Checker was released on November 18, 2019. The app has not received an update since then.

### Does ISC DNS Checker have ads?

No, ISC DNS Checker does not contain advertisements. It is an ad-free application.

## Version history (last 4 releases)

### 0.15 — 2019-11-18

Bug fixes for iOS 13

### 0.14 — 2018-04-25

Bug fixes for iOS updates

### 0.13 — 2017-02-13

- fix for crash in Unknown RRTYPE test if no answer is received
- includes app version number in share output

### 0.12 — 2017-02-10

No release notes.

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## More apps by Internet Systems Consortium, Inc.

- [ISC Dig](https://appshunter.io/ios/app/isc-dig/id1115648880)
- [DNS Root Explorer](https://appshunter.io/ios/app/dns-root-explorer/id6446278686)

All apps by Internet Systems Consortium, Inc.: https://appshunter.io/developer/1115648879

## Related topics

[isc dns checker](https://appshunter.io/ios/topics/isc-dns-checker)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-25.*