# Teensy 4.0 Either IP 0.0.0.0, or IP 0.0.0.0 and DNS 1 and 2 are 0.0.0.0

**URL:** <https://community.sparkfun.com/t/teensy-4-0-either-ip-0-0-0-0-or-ip-0-0-0-0-and-dns-1-and-2-are-0-0-0-0/68406>\
**Category:** Teensy\
**Created:** [March 25, 2026, 4:10pm UTC](https://community.sparkfun.com/t/teensy-4-0-either-ip-0-0-0-0-or-ip-0-0-0-0-and-dns-1-and-2-are-0-0-0-0/68406 "2026-03-25T16:10:36Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![kwonson](https://avatars.discourse-cdn.com/v4/letter/k/50afbb/32.png) [@kwonson](https://community.sparkfun.com/u/kwonson)\
**Post date:** [March 25, 2026, 4:10pm UTC](https://community.sparkfun.com/t/teensy-4-0-either-ip-0-0-0-0-or-ip-0-0-0-0-and-dns-1-and-2-are-0-0-0-0/68406/1 "2026-03-25T16:10:36Z")

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A have 2 defective Teensy 4.0 boards, both used in the same devices and one has an IP of 0.0.0.0, the other has IP 0.0.0.0 and DNS 1 and 2 are 0.0.0.0

We have used 61 of these in the last year in an exact setup and these are the only two exhibiting such behavior. I moved each to working devices and the problem followed (and the good Teensys we had on hand worked perfectly with the two devices with failures, indicating the problem following the boards.

Thanks!

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**Author:** ![TS-Russell](https://yyz1.discourse-cdn.com/sparkfun/user_avatar/community.sparkfun.com/ts-russell/32/6092_2.png) [@TS-Russell](https://community.sparkfun.com/u/TS-Russell)\
**Post date:** [March 26, 2026, 10:08am UTC](https://community.sparkfun.com/t/teensy-4-0-either-ip-0-0-0-0-or-ip-0-0-0-0-and-dns-1-and-2-are-0-0-0-0/68406/2 "2026-03-26T10:08:00Z")

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Darn! Were they purchased from us? If so head over to [Return Policy - SparkFun Electronics](http://www.sparkfun.com/returns) (contact vendor if purchased elsewhere) and we’ll get ya squared away

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**Author:** ![kwonson](https://avatars.discourse-cdn.com/v4/letter/k/50afbb/32.png) [@kwonson](https://community.sparkfun.com/u/kwonson)\
**Post date:** [March 26, 2026, 2:27pm UTC](https://community.sparkfun.com/t/teensy-4-0-either-ip-0-0-0-0-or-ip-0-0-0-0-and-dns-1-and-2-are-0-0-0-0/68406/3 "2026-03-26T14:27:48Z")

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Yes, purchased directly from Sparkfun fairly recently.

Thanks!

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**Author:** ![kwonson](https://avatars.discourse-cdn.com/v4/letter/k/50afbb/32.png) [@kwonson](https://community.sparkfun.com/u/kwonson)\
**Post date:** [April 1, 2026, 8:49pm UTC](https://community.sparkfun.com/t/teensy-4-0-either-ip-0-0-0-0-or-ip-0-0-0-0-and-dns-1-and-2-are-0-0-0-0/68406/4 "2026-04-01T20:49:26Z")

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Thanks again Russell!

And I just wanted to speak to the rest of the forum:

Sparkfun’s Warranty Replacement service was great. Easy, no fuss, and already have my replaced units in hand (and actually installed in our devices with no issues).