From 6c183f88bb126ef9953f84dc8da557cb24bfbcfe Mon Sep 17 00:00:00 2001 From: Marcio Date: Mon, 16 Jun 2025 09:58:49 +0100 Subject: [PATCH 1/3] added clamping recs --- src/content/docs/magic-transit/how-to/ipv6.mdx | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/content/docs/magic-transit/how-to/ipv6.mdx b/src/content/docs/magic-transit/how-to/ipv6.mdx index adefee925d4073..ce7119bdd754e4 100644 --- a/src/content/docs/magic-transit/how-to/ipv6.mdx +++ b/src/content/docs/magic-transit/how-to/ipv6.mdx @@ -40,4 +40,6 @@ To configure IPv6: 2. In **IPv6 Interface address** enter the IPv6 address assigned to you by Cloudflare for the Cloudflare side of the GRE tunnel. This address is part of a `/127` subnet that is provided to you by your Cloudflare team. 3. Use the other IPv6 address you received from your team to configure your router. -For IPv6 traffic over IPv4 tunnels, the same [MSS clamping](/magic-transit/reference/mtu-mss/#mss-clamping) recommendations apply. +### MSS clamping recommendations + +Customers using Magic Transit ingress-only traffic (DSR) should apply a TCP MSS clamp with a maximum of 1416 bytes to their edge router's transit ports to account for the larger IPv6 header. From 0ceffcd4d08cca27c7fd81a571951ac5c6a68182 Mon Sep 17 00:00:00 2001 From: Marcio Date: Mon, 16 Jun 2025 10:01:25 +0100 Subject: [PATCH 2/3] refined text --- src/content/docs/magic-transit/how-to/ipv6.mdx | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/content/docs/magic-transit/how-to/ipv6.mdx b/src/content/docs/magic-transit/how-to/ipv6.mdx index ce7119bdd754e4..2b3197ff4251f2 100644 --- a/src/content/docs/magic-transit/how-to/ipv6.mdx +++ b/src/content/docs/magic-transit/how-to/ipv6.mdx @@ -32,7 +32,9 @@ Cloudflare transports IPv6 traffic over an IPv6-over-IPv4 GRE tunnel. Here is ho ## How to configure IPv6 -Since IPv6 works over an existing IPv4 tunnel you will need to choose either an existing IPv4 GRE tunnel or create a new one to test IPv6. All settings that apply to the IPv4 GRE tunnel apply to the IPv6 tunnel as well, and there is only one new field you need to fill out: **IPv6 Interface address**. Here, you enter one of the two IPv6 addresses from the `/127` subnet that Cloudflare automatically allocates for the GRE tunnel. The other, you need to enter in your router. +Since IPv6 works over an existing IPv4 tunnel you will need to choose either an existing IPv4 GRE tunnel or create a new one to test IPv6. All settings that apply to the IPv4 GRE tunnel apply to the IPv6 tunnel as well, except for any MSS clamping you might need to configure — refer to [MSS clamping recommendations](#mss-clamping-recommendations) below for more information. + +To test and set up IPv6 in the Cloudflare dashboard there is only one new field you need to fill out when creating a new IPv4 GRE tunnel or editing an existing one: **IPv6 Interface address**. Here, you enter one of the two IPv6 addresses from the `/127` subnet that Cloudflare automatically allocates for the GRE tunnel. The other, you need to enter in your router. To configure IPv6: From be4c3a060aedee1c9c86d339892543e4053e1568 Mon Sep 17 00:00:00 2001 From: marciocloudflare <83226960+marciocloudflare@users.noreply.github.com> Date: Mon, 16 Jun 2025 10:16:25 +0100 Subject: [PATCH 3/3] Apply suggestions from code review Co-authored-by: Pedro Sousa <680496+pedrosousa@users.noreply.github.com> --- src/content/docs/magic-transit/how-to/ipv6.mdx | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/content/docs/magic-transit/how-to/ipv6.mdx b/src/content/docs/magic-transit/how-to/ipv6.mdx index 2b3197ff4251f2..38921ebb5c0726 100644 --- a/src/content/docs/magic-transit/how-to/ipv6.mdx +++ b/src/content/docs/magic-transit/how-to/ipv6.mdx @@ -34,7 +34,7 @@ Cloudflare transports IPv6 traffic over an IPv6-over-IPv4 GRE tunnel. Here is ho Since IPv6 works over an existing IPv4 tunnel you will need to choose either an existing IPv4 GRE tunnel or create a new one to test IPv6. All settings that apply to the IPv4 GRE tunnel apply to the IPv6 tunnel as well, except for any MSS clamping you might need to configure — refer to [MSS clamping recommendations](#mss-clamping-recommendations) below for more information. -To test and set up IPv6 in the Cloudflare dashboard there is only one new field you need to fill out when creating a new IPv4 GRE tunnel or editing an existing one: **IPv6 Interface address**. Here, you enter one of the two IPv6 addresses from the `/127` subnet that Cloudflare automatically allocates for the GRE tunnel. The other, you need to enter in your router. +To test and set up IPv6 in the Cloudflare dashboard there is only one new field you need to fill out when creating a new IPv4 GRE tunnel or editing an existing one: **IPv6 Interface address**. Here, you enter one of the two IPv6 addresses from the `/127` subnet that Cloudflare automatically allocates for the GRE tunnel. You need to enter the other IPv6 address in your router. To configure IPv6: @@ -44,4 +44,4 @@ To configure IPv6: ### MSS clamping recommendations -Customers using Magic Transit ingress-only traffic (DSR) should apply a TCP MSS clamp with a maximum of 1416 bytes to their edge router's transit ports to account for the larger IPv6 header. +Customers using Magic Transit ingress-only traffic (DSR) should apply a TCP MSS clamp with a maximum of 1,416 bytes to their edge router's transit ports to account for the larger IPv6 header.