commit 39de84ab4c14c48f74b827eb0d4945910eb83c78
author Maciej Żenczykowski <maze@google.com> Tue Aug 12 19:51:56 2025 -0700
committer Maciej Żenczykowski <maze@google.com> Thu Aug 14 09:37:48 2025 -0700
tree ecfd27de44c1b03e574397daaa91c01a9fe5a4de
parent c37f3cf83d7c5d19b259be7cc6fa724dec843938

Tethering: allow ipv6 1500 mtu again

but still fallback to 1400 if we don't know any better

Bug: 432676104
Test: TreeHugger, mm in p/m/C
Flag: EXEMPT mainline
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I7e1d70e73d2fd24d1f79dc40f3b18a6d82d235ef

Tethering/src/android/net/ip/IpServer.java

diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index f516103..b70df59 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -862,8 +862,8 @@
             for (RouteInfo route : v6only.getRoutes()) {
                 if (route.getMtu() >= 1280) pmtu6 = Math.min(pmtu6, route.getMtu());
             }
-            // Clamp v6 MTU to 1280-1400 range.
-            pmtu6 = Math.max(1280, Math.min(1400, pmtu6));
+            // Clamp v6 MTU to 1280-1500 range.
+            if (pmtu6 > 1500) pmtu6 = 1500;
             params.mtu = pmtu6;
             params.hasDefaultRoute = v6only.hasIpv6DefaultRoute();