SDN VXLAN Troubleshooting Tools

ScottO

New Member
Jul 8, 2026
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I have successfully build and deployed a multisite and multidatacenter PVE environment using VXLAN SDN between the sites to extend Layer 2 networking.

I am looking for command line tools to assist in troubleshooting the VXLAN topology. When building similar configurations in the physical network we have tools to aid us in seeing VTEP peering states and the routing for specific MAC addresses to their destination VTEPS. I have not discovered any such command line tools yet within PVE. Hoping someone may be able to point me in the direction of some good documentation with comprehensive CLI tools.

Thanks!
 
Hey,

each pve node renders the configured VXLAN into /etc/network/interfaces.d/sdn, ifupdown2 then reads this. For VXLAN there is no peering, this is how packets leaving the host get encapsulated, and how they get decapsulated at the target host again. So there is no peering state that you could look at. A dead peer looks the same (aside from maybe the fdb) as an alive one for others. Things you can use are all the variations of the ip [link|a|..] ... command, bridge ... , tcpdump is also useful

Code:
# tunnel, if you did not change the vxlan-port, it is 4789
tcpdump -ni <underlay_nic> udp port 4789

# decapsulated traffic
tcpdump -ni vxlan_<name>

# what guests see
tcpdump -ni <vnet>

and of course ping.
 
I have successfully build and deployed a multisite and multidatacenter PVE environment using VXLAN SDN between the sites to extend Layer 2 networking.

I am looking for command line tools to assist in troubleshooting the VXLAN topology. When building similar configurations in the physical network we have tools to aid us in seeing VTEP peering states and the routing for specific MAC addresses to their destination VTEPS. I have not discovered any such command line tools yet within PVE. Hoping someone may be able to point me in the direction of some good documentation with comprehensive CLI tools.

Thanks!
you can also use frr tool to show routing tables

vtysh -c "show bgp l2vpn evpn"