ARP Issue inside LXC

[opendsi]

Hi everyone.

We got troubles with MAC(ARP) inside LXC container.

LXC :

root@LXC2:~# arp -a
nano-eth0-4.XXXX.lan (192.168.77.1) at 00:09:0f:09:00:1a [ether] on eth0
dcvy01-br4.XXXX.lan (192.168.77.254) at 00:09:0f:09:00:1a [ether] on eth0
dcnxnas.XXXX.lan (192.168.77.8) at 00:50:56:85:0a:c6 [ether] on eth0
srvdc02.XXXX.local (192.168.77.40) at 00:50:56:95:2d:11 [ether] on eth0
dcnxmysql.XXXX.lan (192.168.77.7) at 00:50:56:85:de:c9 [ether] on eth0
dcparapheur.XXXX.lan (192.168.77.55) at <incomplete> on eth0


PVE HOST :

root@dcnxproxmox:~# arp -a
dcnxnas.XXXX.lan (192.168.77.8) at 00:50:56:85:0a:c6 [ether] on vmbr0
nano-eth0-4.XXXX.lan (192.168.77.1) at 00:09:0f:09:00:1a [ether] on vmbr0
dcvy01-br4.XXXX.lan (192.168.77.254) at 00:09:0f:09:00:1a [ether] on vmbr0
srvdc02.XXXX.local (192.168.77.40) at 00:50:56:95:2d:11 [ether] on vmbr0
dcparapheur.XXXX.lan (192.168.77.55) at 00:50:56:85:fc:9c [ether] on vmbr0


INSIDE OTHER LXC



arp -s 192.168.77.55 00:50:56:85:fc:9c

root@LXC1:~# arp -a
dcnxmysql.XXXX.lan (192.168.77.7) at 00:50:56:85:de:c9 [ether] on eth0
dcnxnas.XXXX.lan (192.168.77.8) at 00:50:56:85:0a:c6 [ether] on eth0
nano-eth0-4.XXXX.lan (192.168.77.1) at 00:09:0f:09:00:1a [ether] on eth0
dcvy01-br4.XXXX.lan (192.168.77.254) at 00:09:0f:09:00:1a [ether] on eth0
srvdc02.XXXX.local (192.168.77.40) at 00:50:56:95:2d:11 [ether] on eth0
dcparapheur.XXXX.lan (192.168.77.55) at 00:50:56:85:fc:9c [ether] PERM on eth0

When we force MAC adress it's work.



root@dcnxproxmox:~# pveversion
pve-manager/5.2-5/eb24855a (running kernel: 4.15.18-1-pve)


root@dcnxproxmox:~# cat /etc/sysctl.conf
net.ipv4.conf.all.rp_filter=1
net.ipv4.icmp_echo_ignore_broadcasts=1
net.ipv4.conf.default.forwarding=1
net.ipv4.conf.default.proxy_arp = 0
net.ipv4.ip_forward=1
kernel.sysrq = 1
net.ipv4.conf.default.send_redirects = 1
net.ipv4.conf.all.send_redirects = 0
vm.swappiness=1
fs.inotify.max_user_instances=512
fs.inotify.max_user_watches=16384


Best regards

 

[oguz]

hi,

root@dcnxproxmox:~# pveversion
pve-manager/5.2-5/eb24855a (running kernel: 4.15.18-1-pve)

i'd recommend you to upgrade. you are running quite an old version, and upgrading might solve your problem if this issue was already fixed.