From 3c4f65c59c52b3bfe88ef4d4b1bb421246afafa3 Mon Sep 17 00:00:00 2001 From: Reuben Dowle Date: Fri, 26 Feb 2021 10:10:48 +1300 Subject: [PATCH] nhrpd: Document multicast functionality Signed-off-by: Reuben Dowle --- doc/user/nhrpd.rst | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/doc/user/nhrpd.rst b/doc/user/nhrpd.rst index b02e761acc..c7c4975aee 100644 --- a/doc/user/nhrpd.rst +++ b/doc/user/nhrpd.rst @@ -180,6 +180,34 @@ https://git-old.alpinelinux.org/user/tteras/strongswan/ Actively maintained patches are also available at: https://gitlab.alpinelinux.org/alpine/aports/-/tree/master/main/strongswan +.. _multicast-functionality: + +Multicast Functionality +======================= + +nhrpd can be configured to forward multicast packets, allowing routing +protocols that use multicast (such as OSPF) to be supported in the DMVPN +network. + +This support requires an NFLOG redirection rule to work: + + .. code-block:: shell + + iptables -I OUTPUT -d 224.0.0.0/24 -o gre1 -j NFLOG --nflog-group 2 + +.. index:: nhrp multicast-nflog-group (1-65535) +.. clicmd:: nhrp multicast-nflog-group (1-65535) + + Sets the nflog group that nhrpd will listen on for multicast packets. This + value must match the nflog-group value set in the iptables rule. + +.. index:: ip nhrp map multicast A.B.C.D|X:X::X:X A.B.C.D|dynamic +.. clicmd:: ip nhrp map multicast A.B.C.D|X:X::X:X A.B.C.D|dynamic + + Sends multicast packets to the specified NBMA address. If dynamic is + specified then destination NBMA address (or addresses) are learnt + dynamically. + .. _nhrp-events: NHRP Events -- 2.39.5