default route with linkdown

Question

If no link on enp0s18 i have

root@route:~# ip r
default via a.a.a.1 dev enp0s18 metric 10 linkdown 
default via a.a.b.1 dev enp0s10 metric 20 onlink linkdown 
default via x.x.x.49 dev wwx001e101f0000 metric 30 

Expected that default swiches to x.x.x.49, but it tries linkdown route

root@route:~# ping -n ya.ru
PING ya.ru (87.250.250.242) 56(84) bytes of data.
From a.a.a.231 icmp_seq=1 Destination Host Unreachable
From a.a.a.231 icmp_seq=2 Destination Host Unreachable
From a.a.a.231 icmp_seq=3 Destination Host Unreachable
^C

Link state

4: enp0s10: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether 1c:af:f7:08:27:e2 brd ff:ff:ff:ff:ff:ff
5: enp0s18: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:13:d3:14:83:f1 brd ff:ff:ff:ff:ff:ff

Result: Traffic black-holed

Solution

In new kernel we have new defaults. Solution is

echo 1 > /proc/sys/net/ipv4/conf/enp0s10/ignore_routes_with_linkdown
echo 1 > /proc/sys/net/ipv4/conf/enp0s18/ignore_routes_with_linkdown

And make new default

echo net.ipv4.conf.all.ignore_routes_with_linkdown=1 > /etc/sysctl.d/10-linkdown.conf
sysctl -p /etc/sysctl.d/10-linkdown.conf

Comments

[eri]

Create this file. If you have no /etc/sysctl.d/ dir - append this "net.ipv4.conf.all.ignore_routes_with_linkdown=1" to /etc/sysctl.conf

[Nikita]

But there is no /etc/sysctl.conf as well

[eri]

create it. look to dmesg to check

[AJ Smith 'Smugger']

Why have you not accepted your own answer? It does work...