Pseudo-Ethernet or MACVLAN interfaces can be seen as subinterfaces to regular ethernet interfaces. Each and every subinterface is created a different media access control (MAC) address, for a single physical Ethernet port. Pseudo- Ethernet interfaces have most of their application in virtualized environments,
By using Pseudo-Ethernet interfaces there will be less system overhead compared to running a traditional bridging approach. Pseudo-Ethernet interfaces can also be used to workaround the general limit of 4096 virtual LANs (VLANs) per physical Ethernet port, since that limit is with respect to a single MAC address.
Every Virtual Ethernet interfaces behaves like a real Ethernet interface. They can have IPv4/IPv6 addresses configured, or can request addresses by DHCP/ DHCPv6 and are associated/mapped with a real ethernet port. This also makes Pseudo-Ethernet interfaces interesting for testing purposes. A Pseudo-Ethernet device will inherit characteristics (speed, duplex, …) from its physical parent (the so called link) interface.
Once created in the system, Pseudo-Ethernet interfaces can be referenced in the exact same way as other Ethernet interfaces. Notes about using Pseudo- Ethernet interfaces:
- Pseudo-Ethernet interfaces can not be reached from your internal host. This means that you can not try to ping a Pseudo-Ethernet interface from the host system on which it is defined. The ping will be lost.
- Loopbacks occurs at the IP level the same way as for other interfaces, ethernet frames are not forwarded between Pseudo-Ethernet interfaces.
- Pseudo-Ethernet interfaces may not work in environments which expect a NIC to only have a single address. This applies to: - VMware machines using default settings - Network switches with security settings allowing only a single MAC address - xDSL modems that try to lear the MAC address of the NIC
Configure interface <interface> with one or more interface addresses.
- address can be specified multiple times as IPv4 and/or IPv6 address, e.g. 192.0.2.1/24 and/or 2001:db8::1/64
- dhcp interface address is received by DHCP from a DHCP server on this segment.
- dhcpv6 interface address is received by DHCPv6 from a DHCPv6 server on this segment.
set interfaces pseudo-ethernet peth0 address 192.0.2.1/24 set interfaces pseudo-ethernet peth0 address 192.0.2.2/24 set interfaces pseudo-ethernet peth0 address 2001:db8::ffff/64 set interfaces pseudo-ethernet peth0 address 2001:db8:100::ffff/64
SLAAC RFC 4862. IPv6 hosts can configure themselves automatically when connected to an IPv6 network using the Neighbor Discovery Protocol via ICMPv6 router discovery messages. When first connected to a network, a host sends a link-local router solicitation multicast request for its configuration parameters; routers respond to such a request with a router advertisement packet that contains Internet Layer configuration parameters.
This method automatically disables IPv6 traffic forwarding on the interface in question.