vxlanfdb

Documentation

Index

• Variables
• type Option
  • func WithNetlinkHandleShim(newNetlinkHandle func() (netlinkshim.Interface, error)) Option
• type VTEP
• type VXLANFDB
  • func New(family int, ifaceName string, featureDetector environment.FeatureDetectorIface, ...) *VXLANFDB
  • func (f *VXLANFDB) Apply() error
  • func (f *VXLANFDB) OnIfaceStateChanged(ifaceName string, state ifacemonitor.State)
  • func (f *VXLANFDB) QueueResync()
  • func (f *VXLANFDB) SetVTEPs(vteps []VTEP)

Variables

var ErrLinkDown = fmt.Errorf("VXLAN device is down")

Types

type Option

type Option func(*VXLANFDB)

func WithNetlinkHandleShim

func WithNetlinkHandleShim(newNetlinkHandle func() (netlinkshim.Interface, error)) Option

type VTEP

type VTEP struct {
	// HostIP is the remote node's real IP address; the IP that we send the
	// VXLAN packets to.
	HostIP ip.Addr
	// TunnelIP is the IP of the remote tunnel device, which we use as
	// a gateway for the remote workloads..
	TunnelIP ip.Addr
	// TunnelMAC is the MAC address of the remote tunnel device.
	TunnelMAC net.HardwareAddr
}

type VXLANFDB

type VXLANFDB struct {
	// contains filtered or unexported fields
}

VXLANFDB manages the FDB and ARP/NDP entries for a VXLAN device. I.e. all the layer-2 state for the VXLAN device.

Overall, we use VXLAN to create a layer 3 routed network. We do that by

• Giving each node a "tunnel IP" which is an IP on the Calico VXLAN network. this IP is allocated from a VXLAN IP pool.
• (In this object) setting up static ARP/NDP entries for the tunnel IPs.
• (In this object) setting up static FDB entries for the tunnel MACs.
• (Elsewhere) setting up a routes to remote workloads via the tunnel IPs.

ARP/NDP entries and FDB entries are confusingly similar(!) Both are MAC/IP tuples, but they mean very different things. ARP/NDP entries tell the kernel what MAC address to use for the inner ethernet frame inside the VXLAN packet. FDB entries tell the kernel what IP address to use for the outer IP header, given a particular inner MAC. So, ARP maps IP->(inner)MAC; FDB maps (inner)MAC->(outer)IP.

From a packet's point of view, routing works like this:

• A local workload or this host sends a packet to a remote workload.
• The packet hits a route of the form <remote workload IPAM block> via <remote tunnel IP> dev <VXLAN device> onlink which sends it to the VXLAN device for encapsulation.
• The ARP entry resolves the remote tunnel IP to the remote tunnel MAC.
• The FDP entry resolves the remote tunnel MAC to the remote host's real IP.
• The packet is encapsulated and sent to the remote host's real IP.

func New

func New(
	family int,
	ifaceName string,
	featureDetector environment.FeatureDetectorIface,
	netlinkTimeout time.Duration,
	opts ...Option,
) *VXLANFDB

func (*VXLANFDB) Apply

func (f *VXLANFDB) Apply() error

func (*VXLANFDB) OnIfaceStateChanged

func (f *VXLANFDB) OnIfaceStateChanged(ifaceName string, state ifacemonitor.State)

func (*VXLANFDB) QueueResync

func (f *VXLANFDB) QueueResync()

func (*VXLANFDB) SetVTEPs

func (f *VXLANFDB) SetVTEPs(vteps []VTEP)