VMware 2012 presentation INF-VSP1196: What’s new with vCloud Director Networking
This session was discussed the new networking features of vCloud Director 5.1 (VMware decided to sync the version with the release of vSphere 5.1, jumping from 1.5.1 all the way to 5.1).
From the presentation content, the bulk of changes focus vShield Edge and VxLAN. vShield now is bundled in two ways: Security and Advanced and sold as Standard or Enterprise. More will be discussed below about the changes, but in short the actual Edge VM is deployed in two sizes, with different supported features.
New features of vShield Edge:
- Multiple interfaces, up to 10, are now supported with the Advanced bundle. This is an increase of 2.
- The virtual hardware is now 7.
- The appliance, as stated before, can be deployed as the compact or full version of edge. The major difference, according the presentation, is the support for higher throughput and a active/standby edge appliance. I for one welcome the change since the current instantiation of Edge only allowed for a respawn of a device which required an outage.
- The Edge appliance can act as a DNS relay for internal clients.
- External address space can be increased on the fly.
- Non-contiguous networks can be applied to the external interface of the vShield Edge.
- Ability to sub-allocate IP addresses to Organization vDCs.
With vCloud Director version 5.1, a new network object is available for use by Organizations: Organization vDC (virtual datacenter) Networks. Since an Organization Network (OrgNet) is mapped to a single Organization, the new Org vDC Network can now span multiple org vDC within an Organization. The fellow glossed over the use-case for this situation, and one does not easily come to mind at the moment.
VMware is also debuting something they call Service Insertion. This is basically a new security API for 3rd party vendors to integrate directly in to the networking stack for their products. Profiles can now be created based on services, and these profiles can then be applied to a Port Group of a Distributed Switch. I do believe VMware is attempting to allow providers to create billing and a-la carte models to generate income from their clients. It is an interesting play to see if it is really used only in Public offerings, or if private clouds offer it in a charge-back model.
Edge can provide a DHCP service, available on isolated networks. You now can use:
- Multiple DHCP pools per edge device (necessary with 10 supported interfaces).
- Single pool per interface.
- No option for advanced features such as lease times.
- Rules can be applied to an interface.
- Rules can be arranged via a drag and drop interface, but they are evaluated from top down. The first hit causes an exit.
- Source NAT (SNAT) and Destination NAT (DNAT) supports: TCP, UDP, TCP and UDP, ICMP or any.
- There are predefined ICMP types.
- VMware is still trumpeting their Edge firewall as 5 tuple (5 different options for filtering, but it still isn’t all that great).
- Rules can be arranged via drag and drop.
- Logging per rule.
- Support for TCP, UDP, TCP and UDP.
- Can not filter on ICMP types (ping versus traceroute). I do believe it is all or nothing.
- VMware stated it is useful for routing between Org networks. I think this use-case would be for far more advanced configurations.
- Can be used for deep reach in vApp networks. The current Edge device does support static routing even when using vCDNI, but the MAC in MAC encapsulation adds some serious latency to the connections. I suspect VxLAN is to thank for this configuration to be better supported.
- IPsec or SSL site to site configuration, not for user remote access.
- Compatible with 3rd party software and hardware VPN, since Edge is doing IPsec or SSL. Nothing proprietary there.
- Load Balance on HTTP, HTTPS or any old TCP port.
- Can conduct a basic health check of the back-end servers with either a URI (except for HTTPS) or tcp port.
- Configure pool servers and VIP.
- Balance on IP Hash, URI or least connections.
- NOTE: The current version uses nginx. I saw it not work even close to correctly with certain network configurations based around VCDNI. Let’s hope it works better in this version.
Virtual Service (Load balancing)
- HTTPS can use session IDs.
- There is no persistence option for regular TCP ports.
And now for the queen mother of all session topics: VXLAN. Boiling it down, VXLAN allows for a layer 2 network, say 192.168.100.0/24, to exist live in two places at once. Think 2 datacenters, or in this case, the Cloud.
- Layer 2 overlay on a Layer 3 network .
- Each overlay network is known as a VXLAN segment.
- VXLAN identified by 24 bit segment ID, known as a VNI.
- Traffic carried by VXLAN tunnel endpoints, known as VTEP.
- ESXi hosts or Cisco Nexus 1000v can act as VTEP.
- Virtual machines have no idea of the existence of VXLAN transporting their traffic.
- VM to VM traffic is encapsulated in a VXLAN header.
- Traffic on same portgroup is not encapsulated.
- Here is the big kicker: multicast is required
- Used for VM broadcast and multicast messages
- In essence, a dedicated virtual Distributed Switch
- Available vNIC and IP address per switch
- Mutlicast addresses
- Multicast configured on the physical network
- Requires multicast end to end (all networking points between the VTEP).
- Minimum MTU of 1600 (in the network).
The technology sounds cool, is hopefully better than VCDNI, but the requirement of multicast may be a show-stopper to some people.