# Server tests ULA instead of GUA address

**URL:** <https://forums.plex.tv/t/server-tests-ula-instead-of-gua-address/943544>\
**Category:** Remote Access\
**Tags:** server-mac, networking\
**Created:** [September 27, 2026, 8:33pm UTC](https://forums.plex.tv/t/server-tests-ula-instead-of-gua-address/943544 "2026-09-27T20:33:50Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![certuna](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@certuna](https://forums.plex.tv/u/certuna)\
**Post date:** [September 27, 2026, 8:33pm UTC](https://forums.plex.tv/t/server-tests-ula-instead-of-gua-address/943544/1 "2026-09-27T20:33:50Z")

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Server Version#: 1.43.4.10903  
Player Version#: Web 4.160.0

Looking at the Settings/Remote Access, it looks like PMS tests the server’s ULA address (in the fd00::/8 range) instead of its GUA (from 2000::/3) address if it has both. And then, unsurprisingly, displays that the server is “not available outside your network”.

(server is IPv6-only, secure connections Required, strict TLS, no custom server access URLs)

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**Author:** ![certuna](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@certuna](https://forums.plex.tv/u/certuna)\
**Post date:** [October 4, 2026, 11:30am UTC](https://forums.plex.tv/t/server-tests-ula-instead-of-gua-address/943544/2 "2026-10-04T11:30:28Z")

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Somewhat related: client apps seem to prefer IPv4 over IPv6, which is problematic when you have an IPv4 proxy (custom URL) to cater for remote clients on IPv4-only networks: instead of using IPv6-\>IPv6, dual stack clients will always take the IPv4 route over the internet (LAN → WAN IPv4 proxy → LAN) instead of IPv6 → IPv6.

Can be reproduced by:

- set up an IPv4-\>IPv6 reverse proxy with an A record for [https://plex.example.com](https://plex.example.com) and add this to the Custom URL
- set PMS to IPv6-only, remote access on (reachable over TCP port 32400, obviously)
- use any Plex client app (iOS, tvOS) on a dual stack network

Expected: only IPv4-only clients use the proxy, IPv6-capable clients go direct

Observed: dual stack clients use the proxy, even when they are on the same /64 LAN as the server

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**Author:** ![Qtip](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/qtip/32/340928_2.png) [@Qtip](https://forums.plex.tv/u/Qtip)\
**Post date:** [October 4, 2026, 1:50pm UTC](https://forums.plex.tv/t/server-tests-ula-instead-of-gua-address/943544/3 "2026-10-04T13:50:52Z")

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I posted this behavior [here](https://forums.plex.tv/t/solved-plex-on-samsung-tv-unable-to-connect-to-local-server-after-update-to-1-43-3/941572/5), but nobody readed this!!

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**Author:** ![certuna](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@certuna](https://forums.plex.tv/u/certuna)\
**Post date:** [October 4, 2026, 11:18pm UTC](https://forums.plex.tv/t/server-tests-ula-instead-of-gua-address/943544/4 "2026-10-04T23:18:13Z")

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Plex should publish the ULA addresses to the clients, otherwise it may not be reachable by clients on that network. But it should always follow RFC6724 in prioritizing: first IPv6 GUA → IPv4 → IPv6 ULA, it seems it doesn’t do this unfortunately.