Follow the comment,
I agree with that TES is not a trusted entity in nvo3. In my point of
view, the trust model for nvo3 is a basis for dicussing security issues.
The following figure attempts to explicitly describe nov3 trust model in
draft-wei-nvo3-security-framework.
+------------------------------------+
| Trusted |
| +--------------------+ |
| |+------------------+| |
| || Virtual Network 1|| |
| |+------------------+| |
+----------+ | +-----++------------------++-----+ |
|Tenant End| | | || Virtual Network 2|| | | +----------+
| System +----+ NV |+------------------+| NV | | |Tenant End|
+----------+ | |Edge |+------------------+| Edge+----+ System |
| | || Virtual Network 3|| | | +----------+
Untrusted | +-----++------------------++-----+ |
| | L3 Overlay Network | | Untrusted
| | | |
| +--+---------------+-+ |
| | Overlay | |
| | Boundary Point| |
| +-------+-------+ |
+------------------|-----------------+
|
+----------+---------+
| Underlying Network | Untrusted
+--------------------+
Figure 1: Security Reference Model for Overlay based Network
Virtualization
-----------
Yinxing Wei
"Larry Kreeger (kreeger)" <[email protected]>
发件人: [email protected]
2012/07/11 11:06
收件人
"[email protected]" <[email protected]>, "[email protected]"
<[email protected]>, "[email protected]" <[email protected]>
抄送
主题
Re: [nvo3] TES-NVE attach/detach protocol security (mobility-issues draft)
Trying to clarify the discussion below…using the terminology from
draft-lasserre-nvo3-framework-03
A TES (tenant end system) is not a trusted entity and would not use VDP to
communicate to an NVE. It is an "End System" that would use VDP to
communicate to an NVE, which would be a trusted device within the data
center that is administered by the data center operator �C NOT a tenant.
- Larry
From: David Black <[email protected]>
Date: Tuesday, July 10, 2012 9:27 AM
To: "[email protected]" <[email protected]>, "[email protected]" <
[email protected]>
Subject: Re: [nvo3] TES-NVE attach/detach protocol security
(mobility-issues draft)
Linda,
We’re mostly in agreement ...
IEEE802.1 Qbg’s VDP doesn’t do encapsulation, so it is different from
NVo3’s NVE. VDP allows the hypervisor to notify the network of the
virtual network to which the new VMs belong. In that aspect, there is
similarity to NVo3’s NVE.
Right - VDP is a protocol that can be used between TES and NVE. For a
hypervisor, VDP would only be used on a link to an external NVE (e.g., in
the ToR switch). If the NVE is inside the hypervisor there’s no external
TES-NVE protocol because both the TES and NVE are in the same physical
server.
Hypervisor may be trusted, but I don’t think DC operators can trust VMs.
I agree, and VDP approaches this via use of a link-local destination MAC
address for all VDP frames sent to the NVE. If a VM sends a VDP frame,
that frame is received by a virtual switch in the hypervisor, and so a
simple solution is for virtual switches to drop and ignore all VDP frames
sent by VMs. An SR-IOV NIC would be configured to do likewise for VDP
frames sent by VMs. In both cases, this enables an external NVE in a ToR
switch to rely on the VDP frames it receives having been originated by the
hypervisor and not the VMs.
Security will be a big concern for any protocols from TES to NVE.
I agree, and any IP based TES-NVE protocol will be unable to rely on
link-local destination MACs, hence I would expect authentication to be at
least a “MUST implement” requirement if an IP-based protocol is used.
Thanks,
--David
From: Linda Dunbar [mailto:[email protected]]
Sent: Tuesday, July 10, 2012 11:49 AM
To: Black, David; [email protected]
Subject: RE: TES-NVE attach/detach protocol security (mobility-issues
draft)
David,
IEEE802.1 Qbg’s VDP doesn’t do encapsulation, so it is different from
NVo3’s NVE. VDP allows the hypervisor to notify the network of the
virtual network to which the new VMs belong. In that aspect, there is
similarity to NVo3’s NVE.
Hypervisor may be trusted, but I don’t think DC operators can trust VMs.
When VMs are instantiated with applications from random clients, whose
applications can initiate attack to other clients network. It happened
once in Amazon’s EC2.
Security will be a big concern for any protocols from TES to NVE.
Linda
From: [email protected] [mailto:[email protected]]
Sent: Tuesday, July 10, 2012 8:17 AM
To: Linda Dunbar; [email protected]
Subject: TES-NVE attach/detach protocol security (mobility-issues draft)
Hi Linda,
[Linda] In your IEEE802.1Qbg’s VDP example, the NVE would be the
Hypervisor which sends Association/De-association messages to the edge
bridge. I.e. the Hypervisor need to have north bound interface which is
aware a VM is add or deleted.
I don’t think so. If the NVE is in the hypervisor, the external Ethernet
switches (bridges) don’t see the inner MACs after encapsulation, hence
VDP to the external Ethernet switch (bridge) is not useful because it sets
up inner MACs that won’t occur in the outer headers beyond the hypervisor
’s NVE. If the NVE is in the external Ethernet switch (bridge), VDP is
useful because then it’s running between the TES and the NVE.
However, it is a security hole to let TES inform NVEs of being added or
deleted, unless it is in a secure environment, or NVEs (or Hypervisors)
can validate the information from TES via its management system.
I’m not sure that “secure environment” sets the right expectation.
For an external NVE, it’s necessary to trust the hypervisor to provide
info on VM attach/detach, so the security concern is that this info come
only from the hypervisor.
For VDP this starts with use of a link-local destination MAC - if a VM
sends to this MAC, the virtual switch in the hypervisor is the recipient.
That virtual switch doesn’t forward the VDP frames, and probably just
drops them. For an SR-IOV NIC in the server, the virtual switch in the NIC
has to drop VDP frames sent by a VM so that VDP frames originate only from
the hypervisor. If an IP-based protocol is used for this function,
authentication will be needed. For an NVE in the hypervisor, the
hypervisor configures its virtual switch directly and VDP does not run
outside the hypervisor.
Thanks,
--David
From: [email protected] [mailto:[email protected]] On Behalf Of
Linda Dunbar
Sent: Monday, July 09, 2012 3:28 PM
To: Guyingjie (Yingjie); [email protected]
Subject: Re: [nvo3] Comments on draft-dunbar-nvo3-overlay-mobility-issues
Ying Jie,
Thank you very much for the nice comments. My replies are inserted below:
From: Guyingjie (Yingjie)
Sent: Wednesday, July 04, 2012 8:15 PM
To: [email protected]; Linda Dunbar
Subject: Comments on draft-dunbar-nvo3-overlay-mobility-issues
Hi Linda,
I read your draft on NVO3-mobility.
I am okay with most of the content, just some secondary comments on your
description of mechanism between NVE and TES.
In my mind, external controller assistance is a bit more complicate to
implement than using a protocol between NVEs and TES.
A premise of my comments is that NVE is on external network devices, such
as TOR and EOR, and TES are VMs in physical servers.
4.1.1 First paragraph: “NVEs may
not be aware of VMs being added or deleted unless NVEs have a north
bound interface to a controller which can communicate with VM/server
Manager(s).
”
This is not true. In VDP, with an Association/De-association message from
Hypervisor to edge bridge(i.e. NVE in NVO3, and will use NVE instead of
edge bridge in below), the bridge can be timely notified about the connect
and disconnect to the bridge. That means it doesn’t need an northbound
API for NVEs to be aware of VMs (dis)connection. And also, VDP protocol
can carry a field showing “This is a new created VM” or “This is a VM
migrated from somewhere else”. That is VDP can fulfill the requirement of
mobility notification, which can be a trigger for NVE to timely updating
the states on itself, e.g. acquiring VNID associated with the VM
moving/adding to the NVE, inner-outer address mapping, deleting states
associated with the VM moving/deleting from this NVE.
[Linda] In your IEEE802.1Qbg’s VDP example, the NVE would be the
Hypervisor which sends Association/De-association messages to the edge
bridge. I.e. the Hypervisor need to have north bound interface which is
aware a VM is add or deleted.
I think that the sentence should have stated as “NVEs may not be aware of
the VMs being added or deleted unless NVEs have a north bound interface to
a controller which can communicate with VM/Server managers, or there is a
protocol between TES and NVEs as defined by IEEE802.1Qbg.
However, it is a security hole to let TES inform NVEs of being added or
deleted, unless it is in a secure environment, or NVEs (or Hypervisors)
can validate the information from TES via its management system.
In the 4th paragraph of 4.1.1, If, for whatever reason, it is necessary to
have local VID in the
data frames before encapsulating outer header of EgressNVE-DA/
IngressNVE-SA /VNID, NVE should get the specific local VID from the
external Controller for those untagged data frames coming to each
Virtual Access Point
For some reasons, I don’t think this part is good.
First, there is other way to get the local VID except for external
controller. In VDP, when NVE receives a (Pre)Association message from TES,
it can acquire local VID from a Database which is managed by network
administrator.
[Linda] Yes, I should have added that NVE can also get local VID from TES
as IEEE802.1Qbg defined.
Secondly, while defining VDP, we consider of the situation you described,
i.e. different local VID at different location. So the VDP can support
different local VID under different NVE, by getting local VID from
Database while receive the (Pre)Association message. And it can even
feedback to the Hypervisor, so that the data frames from TES could have
the local VID on it, but it’s also okay for NVE to add the local VID to
data frames.
[Linda] it is all good if TES can have those functions. But in many
environment, TES don’t. This paragraph is emphasizing on the scenario
when TES don’t support IEEE802.1Qbg. It is a good idea that you point out
the functions of IEEE802.1Qbg.
In the 6th paragraph in 4.1.1, The IEEE802.1Qbg's VDP protocol (Virtual
Station Interface (VSI)
discovery and configuration protocol) requires hypervisor to send VM
profile upon a new VM is instantiated. However, not all hypervisors
support this function.
The following is the VDP TLV definition from Qbg. Each VSI (Virtual
Station Interface) usually is a VM interface id(could be MAC,IPV4/V6,
UUID, etc).
The NVE gets profile from Database by VSI type & instance information. I
think your profile ID also means the combination of VSI type and instance
information. So we are talking the same thing. My point is it’s not
profile, but the IDs to get profile, that is carried in VDP message. It
might be confusing to people knowing nothing about VDP. Carrying profile
in message is a huge overload.
External Controller can be very useful in NVO3, but not best suitable for
each part of NVO3. I think we should think of other way for different
problems.
[Linda] Thanks for sharing this table.
Linda
Best Regards
Gu Yingjie
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