LSDK for LX2160ARDB ipv6 router solicitation packets flooding network

[ash_law]

I have tried everything anyone has suggested to turn off ipv6 on this board.

Tried /etc/sysctl set to :

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.eth1.disable_ipv6 = 1
net.ipv6.conf.eth1.router_solicitations = 0

net.ipv6.conf.all.router_solicitations = 0
net.ipv6.conf.default.router_solicitations = 0
net.ipv6.conf.eth1.autoconf = 1 <tried 1 and 0>
net.ipv6.conf.eth1.accept_ra = 0
net.ipv6.conf.all.autoconf = 1 <tried 1 and 0>
net.ipv6.conf.all.accept_ra = 0
net.ipv6.conf.default.autoconf = 1 <tried 1 and 0>
net.ipv6.conf.default.accept_ra = 0

tried to do it by using sysctl -w for each command individually. The /proc/sys/net/ipv6/conf/all/disable_ipv6 file says 1, which means ipv6 should be disabled. But the router solicitation packets keep pouring out.

This does stop it on a regular machine running Ubuntu 18.04 LTS.

Tried it through netplan with /etc/netplan/my_setup.yaml

network:
  version: 2
  renderer: networkd
  ethernets:
    eth1:
      dhcp4: false
      dhcp6: false

      accept-ra: no
      addresses: [192.168.1.83/24]
      gateway4: 192.168.1.83

Some folks say to disable it through GRUB but that doesn't seem applicable.

tcpdump -i eth1 produces

02:58:12.590923 IP6 fe80::d6ae:52ff:fee7:bd59 > ip6-allrouters: ICMP6, router solicitation, length 16
02:58:12.590929 IP6 fe80::d6ae:52ff:fee7:bd59 > ip6-allrouters: ICMP6, router solicitation, length 16
02:58:12.590930 IP6 fe80::d6ae:52ff:fee7:bd59 > ip6-allrouters: ICMP6, router solicitation, length 16
02:58:12.590932 IP6 fe80::d6ae:52ff:fee7:bd59 > ip6-allrouters: ICMP6, router solicitation, length 16
02:58:12.590933 IP6 fe80::d6ae:52ff:fee7:bd59 > ip6-allrouters: ICMP6, router solicitation, length 16
02:58:12.590934 IP6 fe80::d6ae:52ff:fee7:bd59 > ip6-allrouters: ICMP6, router solicitation, length 16
02:58:12.590935 IP6 fe80::d6ae:52ff:fee7:bd59 > ip6-allrouters: ICMP6, router solicitation, length 16
02:58:12.590962 IP6 fe80::d6ae:52ff:fee7:bd59 > ^Clength 16

263 packets captured
308162 packets received by filter
307843 packets dropped by kernel

and my network is flooded by these 16 byte ICMP6 packets.

Anyone with any ideas, please help.

[yipingwang]

Hello Ash Law,

To disable IPv6, you need to input 3 commands.

sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1

sudo sysctl -w net.ipv6.conf.default.disable_ipv6=1

sudo sysctl -w net.ipv6.conf.lo.disable_ipv6=1

To make this option persist.
Modify the file /etc/sysctl.conf to add the following lines.

net.ipv6.conf.all.disable_ipv6=1

net.ipv6.conf.default.disable_ipv6=1

net.ipv6.conf.lo.disable_ipv6=1

For the settings to take effect use:

$ sudo sysctl -p
Create (with root privileges) the file /etc/rc.local and fill it with:

#!/bin/bash

# /etc/rc.local

/etc/sysctl.d

/etc/init.d/procps restart

exit 0

$ sudo chmod 755 /etc/rc.local

[ash_law]

That doesn’t work. Creating the rc.local file as suggested hangs the boot. I waited for 2 minutes. Just says waiting for job with no time limit.

Setting the /etc/sysctl.conf entries seems to remove ipv6 addressing from the interfaces. But we still get flooded by router solicitation packets.

Thanks

Ash

[yipingwang]

Hello Ash,

Please Check to see if you have ip6mode=autohost or rtsol{,d}=YES in /etc/rc.conf , comment out those entries if you find them and reboot.

Thanks,

Yiping