This is a toy used to learn VXLAN.
Virtual Extensible LAN (VXLAN) is a network virtualization technology that attempts to address the scalability problems associated with large cloud computing deployments. It uses a VLAN-like encapsulation technique to encapsulate OSI layer 2 Ethernet frames within layer 4 UDP datagrams.
packet encpasulates is not enought for L2 over L3. VXLan device need to implement the following features.
- ARP resolution: Need to reply to ARP request from local servers without broadcasting the ARP packet.
- Destination search: Need to find the destination location corresponding to the destination MAC.
those features refered as VTEP(VXLAN endpoints, which terminate VXLAN tunnels and may be either virtual or physical switch ports, are known as VXLAN tunnel endpoints (VTEPs)).
there are some variations of VETP implementation, we use local agent and virtual VXLan switch run on Linux servers.
Create the vxlan device, Then as each remote host is discovered (either on startup or when they are added), do the following
- Create routing table entry for the remote subnet. It goes via the vxlan device but also specifies a next hop (of the remote host).
- Create a static ARP entry for the remote host IP address (and the VTEP MAC)
- Create an FDB entry with the VTEP MAC and the public IP of the remote daemon.
In this scheme the scaling of table entries is linear to the number of remote hosts - 1 route, 1 arp entry and 1 FDB entry per host.
use etcd as the key-value store to exchange information when remote host status changed(add, delete, update, etc...).
get the lastest release binary.
Run
sudo ./vxlan -etcdEndpoint http://etcd:2379you will get log similar to the following.