[systemd-commits] sysctl.d/50-default.conf

[Tom Gundersen]

 sysctl.d/50-default.conf |    3 +++
 1 file changed, 3 insertions(+)

New commits:
commit ad8bc9ea508740074cead005aa3cfd1ba10a5dac
Author: Tom Gundersen <teg at jklm.no>
Date:   Fri Jul 25 11:08:23 2014 +0200

    sysctl.d: enable promote_secondaries by default
    
    Without this, secondary addresses would get deleted when the primary one is. This is not
    the desired behavior when one would like to transition from one address to another in the
    same subnet (such as when a new IP address is given over DHCP).
    
    In networkd, when given a new IP over DHCP we will add it, without explicitly removing the
    old one first (and hence never have a window without an IP address configured). Assuming the
    addresses are in the same subnet, that means that the old address is the primary and the new
    address is the secondary one. Once the old address expires, the kernel will drop it. With the
    old behavior this means that both addresses would be lost, which is clearly not what we want.
    With the new behavior, only the old address is lost, and the new one is promoted to primary.
    
    Reported by Michael Olbrich <m.olbrich at pengutronix.de>

diff --git a/sysctl.d/50-default.conf b/sysctl.d/50-default.conf
index 46bae21..1ee3698 100644
--- a/sysctl.d/50-default.conf
+++ b/sysctl.d/50-default.conf
@@ -19,6 +19,9 @@ net.ipv4.conf.default.rp_filter = 1
 # Do not accept source routing
 net.ipv4.conf.default.accept_source_route = 0
 
+# Promote secondary addresses when the primary address is removed
+net.ipv4.conf.default.promote_secondaries = 1
+
 # Enable hard and soft link protection
 fs.protected_hardlinks = 1
 fs.protected_symlinks = 1