[SOLVED] No internet with specific static IP

[mfreudenberg]

Hi,

i'm currently facing a strange issue with a LXC container that has a static IP assigned. I have created and installed the container using the static IP 192.168.1.215/24. But afterwards i wanted to change it to 192.168.1.205/24 to match my scheme. After doing so i realized that, the container had no internet access. Pinging any external domain from within the container resulted in a timeout

root@container:~$ ping heise.de
PING heise.de (193.99.144.80) 56(84) bytes of data.
From container.mydomain.de (192.168.1.205) icmp_seq=10 Destination Host Unreachable
From container.mydomain.de (192.168.1.205) icmp_seq=14 Destination Host Unreachable
From container.mydomain.de (192.168.1.205) icmp_seq=15 Destination Host Unreachable

Pinging my router (192.168.1.1) did not work either. But when i changed the IP address to 192.168.1.206, everything was fine.

I can ping the container from an external machine when it's IP is set to 205.
I can ping the container from an external machine, when the IP is set to 206.
I can ping the router from within the container, when the IP is set to 206.
I can ping a device, that is connected to the same switch as my proxmox node from within the container, when the IP is set to 205.
I cannot ping the router from within the container, when the IP is set to 205.
I don't get any icmp response, when the IP is set to 206 and i'm trying to ping 205 and vice versa.

The configuration of the container is as follows:

arch: amd64
cores: 3
features: fuse=1,mount=cifs
hostname: container
memory: 8192
net0: name=eth0,bridge=vmbr0,firewall=1,gw=192.168.1.1,hwaddr=EE:76:47:01:AA:7F,ip=192.168.1.205/24,type=veth
onboot: 1
ostype: ubuntu
rootfs: local-zfs:subvol-205-disk-0,size=16G
swap: 8192

ip a returns:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0@if54: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether ee:76:47:01:aa:7f brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.1.205/24 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::ec76:47ff:fe01:aa7f/64 scope link
       valid_lft forever preferred_lft forever

ip r returns:

default via 192.168.1.1 dev eth0 proto static
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.205

I have checked my router UI and the proxmox node, if any other device has the same IP, but couldn't find anything.

Taking a look into the host messages i can see the following error message:

.. pve kernel: [70279.052842] audit: type=1400 audit(1609756561.771:101): apparmor="STATUS" operation="profile_replace" info="not policy admin" error=-13 label="lxc-205_</var/lib/lxc>//&:lxc-205_<-var-lib-lxc>:unconfined" pid=28342 comm="apparmor_parser"

But I'm not sure if this is related.

I'm not sure how i could analyze the issue? Any logs that might be helpful?

 

[bobmc]

sounds like it could be an issue with the arp cache on your router. will probably resolve itself within a few hours.

 

[mfreudenberg]

Hi,

thanks for the reply. It seems i had a misconfiguration in my router. I checked the faulty IP in the devices section and i had a mobile client configured as VPN device with that particular static IP. After deleting that device everything was fine.

Thanks!

 

[bobmc]

yeah, had to be some sort of address conflict. Glad you got sorted