# 「Last IP address」に「::ffff:」がプレフィックスされる

**URL:** <https://meta.discourse.org/t/last-ip-address-being-prefixed-by/87259>\
**Category:** Product Support\
**Created:** [2018 年 5 月 11 日午後 1:03 UTC](https://meta.discourse.org/t/last-ip-address-being-prefixed-by/87259 "2018-05-11T13:03:51Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![AstonJ](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/astonj/32/215041_2.png) [@AstonJ](https://meta.discourse.org/u/AstonJ)\
**Post date:** [2018 年 5 月 11 日午後 2:45 UTC](https://meta.discourse.org/t/last-ip-address-being-prefixed-by/87259/5 "2018-05-11T14:45:34Z")

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Could this be related:

> <https://stackoverflow.com/questions/29411551/express-js-req-ip-is-returning-ffff127-0-0-1>

> [@](#):
>
> `::ffff:` is a subnet prefix for IPv4 (32 bit) addresses that are placed inside an IPv6 (128 bit) space. IPv6 is broken into two parts, the subnet prefix, and the interface suffix. Each one is 64 bits long, or, 4 groups of 4 hexadecimal characters.

I did add a record to allow IPv6 recently, so could that be it? Do you have IPv6 enabled here?

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