From 75b8d4823696490fc025a97b581439bcb7740604 Mon Sep 17 00:00:00 2001 From: Igor Ryzhov Date: Wed, 12 May 2021 18:49:00 +0300 Subject: [PATCH] doc: update VRF support description Signed-off-by: Igor Ryzhov --- doc/user/Useful_Sysctl_Settings.md | 3 --- doc/user/installation.rst | 23 +++++++++-------------- doc/user/zebra.rst | 4 ++-- 3 files changed, 11 insertions(+), 19 deletions(-) diff --git a/doc/user/Useful_Sysctl_Settings.md b/doc/user/Useful_Sysctl_Settings.md index eaf97b969c..0ebf9119b2 100644 --- a/doc/user/Useful_Sysctl_Settings.md +++ b/doc/user/Useful_Sysctl_Settings.md @@ -56,7 +56,4 @@ net.ipv6.neigh.default.base_reachable_time_ms=14400000 # Use neigh information on selection of nexthop for multipath hops net.ipv4.fib_multipath_use_neigh=1 - -# Allows Apps to Work with VRF -net.ipv4.tcp_l3mdev_accept=1 ``` diff --git a/doc/user/installation.rst b/doc/user/installation.rst index dbd95aca40..f7e45a6231 100644 --- a/doc/user/installation.rst +++ b/doc/user/installation.rst @@ -541,20 +541,15 @@ Additional kernel modules are also needed to support MPLS forwarding. :makevar:`VRF forwarding` General information on Linux VRF support can be found in - https://www.kernel.org/doc/Documentation/networking/vrf.txt. Kernel - support for VRFs was introduced in 4.3 and improved upon through - 4.13, which is the version most used in FRR testing (as of June - 2018). Additional background on using Linux VRFs and kernel specific - features can be found in - http://schd.ws/hosted_files/ossna2017/fe/vrf-tutorial-oss.pdf. - - A separate BGP TCP socket is opened per VRF. - - **Important note** as of June 2018, Kernel versions 4.14-4.18 have a - known bug where VRF-specific TCP sockets are not properly handled. When - running these kernel versions, if unable to establish any VRF BGP - adjacencies, downgrade to 4.13. The issue was fixed in 4.14.57, 4.17.9 - and more recent kernel versions. + https://www.kernel.org/doc/Documentation/networking/vrf.txt. + + Kernel support for VRFs was introduced in 4.3, but there are known issues + in versions up to 4.15 (for IPv4) and 5.0 (for IPv6). The FRR CI system + doesn't perform VRF tests on older kernel versions, and VRFs may not work + on them. If you experience issues with VRF support, you should upgrade your + kernel version. + + .. seealso:: :ref:`zebra-vrf` Building ^^^^^^^^ diff --git a/doc/user/zebra.rst b/doc/user/zebra.rst index 0ad4f79d54..763170c973 100644 --- a/doc/user/zebra.rst +++ b/doc/user/zebra.rst @@ -261,8 +261,6 @@ Link Parameters Commands Allows nexthop tracking to resolve via the default route. This is useful when e.g. you want to allow BGP to peer across the default route. -.. _zebra-vrf: - Administrative Distance ======================= @@ -338,6 +336,8 @@ work FRR must use the same metric when issuing the replace command. Currently FRR only supports Route Replace semantics using the Linux Kernel. +.. _zebra-vrf: + Virtual Routing and Forwarding ============================== -- 2.39.5