From 17c918840fb07e5819f8df03345d7f4a5e5b791c Mon Sep 17 00:00:00 2001 From: Donald Sharp <sharpd@cumulusnetworks.com> Date: Wed, 18 Oct 2017 10:24:28 -0400 Subject: [PATCH] doc: Update VRF documentation metric Two things: 1) Update examples to show usage of metric 2) Discuss reasoning for using such a high metric. Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com> Acked-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> --- Documentation/networking/vrf.txt | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/Documentation/networking/vrf.txt b/Documentation/networking/vrf.txt index 3918dae964d4..8ff7b4c8f91b 100644 --- a/Documentation/networking/vrf.txt +++ b/Documentation/networking/vrf.txt @@ -71,7 +71,12 @@ Setup ip ru add iif vrf-blue table 10 3. Set the default route for the table (and hence default route for the VRF). - ip route add table 10 unreachable default + ip route add table 10 unreachable default metric 4278198272 + + This high metric value ensures that the default unreachable route can + be overridden by a routing protocol suite. FRRouting interprets + kernel metrics as a combined admin distance (upper byte) and priority + (lower 3 bytes). Thus the above metric translates to [255/8192]. 4. Enslave L3 interfaces to a VRF device. ip link set dev eth1 master vrf-blue @@ -256,7 +261,7 @@ older form without it. For example: $ ip route show vrf red - prohibit default + unreachable default metric 4278198272 broadcast 10.2.1.0 dev eth1 proto kernel scope link src 10.2.1.2 10.2.1.0/24 dev eth1 proto kernel scope link src 10.2.1.2 local 10.2.1.2 dev eth1 proto kernel scope host src 10.2.1.2 @@ -282,7 +287,7 @@ older form without it. ff00::/8 dev red metric 256 pref medium ff00::/8 dev eth1 metric 256 pref medium ff00::/8 dev eth2 metric 256 pref medium - + unreachable default dev lo metric 4278198272 error -101 pref medium 8. Route Lookup for a VRF @@ -331,7 +336,7 @@ function vrf_create ip link add ${VRF} type vrf table ${TBID} if [ "${VRF}" != "mgmt" ]; then - ip route add table ${TBID} unreachable default + ip route add table ${TBID} unreachable default metric 4278198272 fi ip link set dev ${VRF} up } -- 2.30.9