arp

  1. V

    How to set up a Proxmox server with VM gateway for failsafe management access with only one public IP?

    I'm setting up Proxmox server with pfSense as a VM to act as the main gateway/firewall. The system is in a remote location with a single ISP connection in passthrough mode providing a public IP. My concern: If the pfSense VM becomes inaccessible, I could lose remote management access to the...
  2. N

    vmxnet3 vNIC and ARP filtering

    I was troubleshooting an issue with two VMs that use CARP to perform IP fail-over. I had disabled MAC filtering on these VMs, but the ARP responses for virtual IPs were never sent from the VMs. I saw somewhere that there may be limitations in ebtables or iptables when using a non-virtio vNIC...
  3. P

    [SOLVED] Problem with hetzner ipv4 on baremetal

    Hello everyone, after hours of fruitless research I'm turning to the community :). I have three hetzner servers, running proxmox 8 (latest kernel), on which I have an ipv4 configuration problem. When setting up the servers, I had only taken ipv6. No worries there and I set up the three servers...
  4. L

    Block incoming ARP requests if destination ip is not part of ipfilter-net[n]

    Hey there, on a large PVE cluster all vms are flooded with many ARP Requests. (PVE 8.1.10 / Linux 6.5.13-3-pve) tcpdump -ennqti any arp ens18 B ifindex 2 88:30:37 Request who-has <redacted> tell <router-ip>, length 46 ens18 B ifindex 2 88:30:37 Request who-has <redacted> tell <router-ip>...
  5. P

    Open vSwitch (OVS) with RSTP and OVSIntPort - ARP issue

    Dear community, We have setup similiar to OVS with RSTP and have a strange issue. The difference to the described setup is, that instead of 10Ge interconnects we have 10Ge and 1Ge Fallback - Uplinks to the switches. So far the VMs are working fine. But from one of the nodes we can not...
  6. L

    ovs-appctl ofproto/trace vmbr0 thinks the bridge name is missing...

    I tried to debug an ARP issue and want to use the command ovs-appctl ofproto/trace vmbr0 as described here. But the command failed with: root@xxx:~# ovs-vsctl --version ovs-vsctl (Open vSwitch) 3.1.0 DB Schema 8.3.1 root@xxx:~# ovs-appctl ofproto/trace vmbr0 syntax error at vmbr0 (or the bridge...
  7. R

    Filter incoming ARP requests

    Hi forum, I'm seeing a lot of ARP request packets ("who-has ... tell ...") in the guest VM, I suspect this is because of a larger VLAN and many unused IPs. Any solution to filter out the ARP broadcast packets flooding into VMs? I'm using PVE 7.4 in bridged mode. Thank you in advance.
  8. J

    Debugging sporadic networking problems on LXC

    I have a 5-node cluster with LXC only. From time to time, some LXC loses connectivity. It's sporadic, sort of random even. But when it happens I am very lost at how to properly debug it to know the specific cause of it. This weekend happened again. Took the chance to upgrade the node from...
  9. L

    Invalid ARP responses cause network problems

    While I have solved the issue, I hope this is helpful to others who run into the same problem. Also, it would be great if someone could verify that this is a sensible approach. Recently, we would lose the network connection to our PVE servers on a semi-regular interval. Virtual machines on that...
  10. B

    [SOLVED] VE 7.1-10 slow to forward ARP replies over bridge

    Hi, After starting a container, a PING from inside the container to any address beyond the host it can take up to a few minutes before the replies start flowing. root@deb-11-container:~# ping 172.20.1.1 PING 172.20.1.1 (172.20.1.1) 56(84) bytes of data. From 172.20.1.181 icmp_seq=1 Destination...
  11. M

    ARP resolution not working while using Firewall and OVS

    PVE 7.1-10 Kernel: Linux 5.15.19-1-pve #1 SMP PVE 5.15.19-1 I have created two vms (id 9000, ip 192.168.200.120 and 9001 IP 192.168.200.121) with ubuntu linux 20.04 on a proxmox 7.1-10 cluster. Both vms have proxmox firewall settings enabled (see configuration below), also the cluster has...
  12. M

    [SOLVED] Why is this simple bridge network not receiving ARP replies correctly?

    Hi. This is my first post. I've been experimenting with Proxmox and have been scratching my head trying to solve this issue for the last day or so. The short version: I have three devices. There is the Proxmox VE host itself (let's call it pve, running Proxmox VE 6.2-11), a single virtualized...
  13. V

    Irrelevant packets as present for every VM on proxmox-host

    My network has some issues. When the network traffic increases, the network connections tend to be very slow even though it's an 10GB network. I'm not sure whether it's proxmox-related or not. Example: VMx = virtual machine x VHx = proxmox virtual host x VM1 = 192.168.0.51 (E2:A9:CC:75:79:AF)...
  14. N

    [SOLVED] Netzwerkkonfiguration (IPv4): Ungültige Pakete (Martian Packets)

    Vor einigen Tagen habe ich festgestellt, dass einige der LXC-Container meinen Proxmox VE Host, der gleichzeitig das Default Gateway ist, nicht mehr erreichen können. Wenn ich also beispielsweise das Interface des Host oder ein System im Internet von einem LXC-Container aus angepingt habe, so...
  15. I

    ARP loop in a OVS topology

    Good afternoon, I hope the community could help me with my problem. I have 3 VMs, each one with an OVS with bridge "br0". The VM1 and VM2 are connected via a GRE tunnel to the Server and via VXLAN tunnels between both. Whenever I run: arping -I br0 10.0.1.10 (or) arping -I br0...
  16. A

    Multiple public IP. Linux Bridge. Stops works

    Hello community, I need your help with my possible easy case (maybe not). I bought dedicated server with multiple IP (20 IPv4), they are assigned on eth0. Distributive Debian 10: I provide example for only one address, default config was: # The loopback network interface auto lo iface lo inet...
  17. S

    ARP table overflow - but only one neighbor

    Hi, i have some kind of legacy setup, which i created with Proxmox 5: I have a bunch of LXC containers which are privileged. Inside the LXC containers, i have installed a docker, and some docker containers. The networking of all this is managed by a VM with OPNsense. This worked fine with...
  18. A

    ARP problems on a bridge

    Hello all, this is my first post and I really hope you can help me with a (at least for me) very weird problem. I set up a cluster of 3 HPE servers where vmbr0 is the internal network and vmbr2 is the DMZ. The VLAN config is done on a Cisco ASA 5516. So no VLAN config on the cluster itself...
  19. V

    openvswitch, bridges and routing

    Hello, up to this point I ran this network configuration on my Proxmox 4.4 node: auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 192.168.2.2 netmask 255.255.255.0 gateway 192.168.2.1 post-up echo 1 >...
  20. BelCloud

    Filter ARP

    Hello Is there any way to filter the ARP replies? Ex: 09:45:12.141931 ARP, Reply xx.xx.xx.xxis-at b2:cb:9f:21:38:a8, length 46 I've had today a customer attempting to use another user's IP. The firewall blocked tcp/udp etc, but he still managed to answer ARP requests making the other...

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