Thanks for your detailed explanation.

With regards
Kings



On Wed, Nov 17, 2010 at 2:44 AM, Tyson Scott <[email protected]> wrote:

> It is not there, who would ever use DNS on a router in production.  In real
> world we would never look at DNS as control or management function on a
> router.  It is a protocol that would typically only be seen in the data
> plane.
>
>
>
> It is not control-plane.  You need to separate what is the control-plane
> and what CPP CPPr are.  They are not the same thing.
>
>
>
> Here is a definition of the control-plane
>
> In routing, the control plane is the part of the router architecture that
> is concerned with drawing the network map, or the information in a (possibly
> augmented) routing table that defines what to do with incoming packets.
> Control plane functions, such as participating in routing protocols, run in
> the architectural control element.[1] In most cases, the routing table
> contains a list of destination addresses and the outgoing interface(s)
> associated with them. Control plane logic also can define certain packets to
> be discarded, as well as preferential treatment of certain packets for which
> a high quality of service is defined by such mechanisms as differentiated
> services.
>
>
>
> What fits under that definition? ARP, IGP, BGP, IGMP, PIM, and other
> protocols that "glue" the network together just as Yusuf describes in his
> book.  These protocols can also be very easily identified because these
> protocols will typically terminate on the interface of the router.  But then
> BGP, IGMP, and PIM have exceptions to that typical rule as well.  I also
> think that if the router can run without it then you can't define it as
> fitting into any portion of the router as a primary function.
>
>
>
> Is that a full list of everything that may terminate on the control-plane,
> no.  But everything else starts to become "may be a control-plane function,
> may be a data plane function".  VPN traffic for example may terminate on the
> control plane or it may simply flow thru the router on the forward path.  If
> you terminate it on the control-plane then you need to take VPN traffic into
> consideration in your protection mechanisms using protection mechanisms like
> "call admission control".  But that isn't there by default because 90% of
> the routers in production don't provide encryption services so 90% of the
> time VPN is not a control-plane function.  So if we go based on a 51% rule
> is the norm that means that VPN is a data plane function right? No we can't
> really say that either.  But trying to fit protocols into a nice box of it
> is data plane/control plane/management plane just doesn't work.  There are
> too many exceptions to make any good rule of thumb.
>
>
>
> Simply said it is not a control-plane function, it is not a management
> plane function it is  not a data plane function.  It is a process that runs
> on the router.  Controlling access to it would be controlled on the host
> control plane sub-interface.  Where is the management-interface also
> defined?  Control-plane host.  Does that make these other protocols
> control-plane protocols?  No they are protocols that may run on the host
> control-plane in management functions.
>
>
>
> Regards,
>
>
>
> Tyson Scott - CCIE #13513 R&S, Security, and SP
>
> Managing Partner / Sr. Instructor - IPexpert, Inc.
>
> Mailto: [email protected]
>
> Telephone: +1.810.326.1444, ext. 208
>
> Live Assistance, Please visit: www.ipexpert.com/chat
>
> eFax: +1.810.454.0130
>
>
>
> IPexpert is a premier provider of Self-Study Workbooks, Video on Demand,
> Audio Tools, Online Hardware Rental and Classroom Training for the Cisco
> CCIE (R&S, Voice, Security & Service Provider) certification(s) with
> training locations throughout the United States, Europe, South Asia and
> Australia. Be sure to visit our online communities at
> www.ipexpert.com/communities and our public website at www.ipexpert.com
>
>
>
> *From:* [email protected] [mailto:
> [email protected]] *On Behalf Of *Eugene Pefti
> *Sent:* Monday, November 15, 2010 10:41 PM
> *To:* 'Kingsley Charles'; 'Pieter-Jan Nefkens'
>
> *Cc:* [email protected]
> *Subject:* Re: [OSL | CCIE_Security] DNS part of which plane
>
>
>
> If we don’t know “why” for this “chicken-egg” debate who will be the
> authority to answer it, folks.
>
> I would never put DNS to management plane let it be Cisco world or anything
> else. And Kings’ finding supports it.
>
>
>
> Eugene
>
>
>
>
>
> *From:* [email protected] [mailto:
> [email protected]] *On Behalf Of *Kingsley Charles
> *Sent:* Sunday, November 14, 2010 9:32 PM
> *To:* Pieter-Jan Nefkens
> *Cc:* [email protected]
> *Subject:* Re: [OSL | CCIE_Security] DNS part of which plane
>
>
>
> If DNS is part of management plane then why isn't it in the following list:
>
> router2(config-cp-host)#management-interface g0/0 allow ?
>   beep    Beep Protocol
>   ftp     File Transfer Protocol
>   http    HTTP Protocol
>   https   HTTPS Protocol
>   snmp    Simple Network Management Protocol
>   ssh     Secure Shell Protocol
>   telnet  Telnet Protocol
>   tftp    Trivial File Transfer Protocol
>   tl1     Transaction Language Session Protocol
>   tls     Transport Layer Security Protocol
>
>
> With regards
> Kings
>
> On Tue, Nov 9, 2010 at 12:50 PM, Pieter-Jan Nefkens <”> wrote:
>
> Hi Kings,
>
>
>
> But DNS is used for management. You can use it, for example, for URL
> filtering, certificate enrollment / verification, etc...
>
> And you might want to consider to let DNS traffic leave out of the
> management interface (thus out-of-band certificate enrollment,  RBL checks,
> url filtering, etc). And that would mean that dns would be part of the
> management plane.
>
>
>
> For me, the control plane basically is the CPU in the router that talks
> with the data plane and allows the setting of hardware entries in the data
> plane and handle all traffic that can't be handled in the data-plane.
>
> This includes the arp entries (arp is then placed in the data plane),
> application layer inspection that can't be handled in hardware, changes of
> routing entries, etc..
>
>
>
> The management plane for me is mostly the ways to configure traffic and how
> the router handles traffic and applications. And then in general all traffic
> that is nog immediately part of routing / switching. (the handling of
> routing protocols is of course on the control plane, as it comes in from all
> interfaces), but you might want to restrict management traffic
>
>
>
> HTH
>
>
>
> Pieter-Jan
>
>
>
> On 9 nov 2010, at 06:33, Kingsley Charles wrote:
>
>
>
> Tyson, DNS is not required to build the network hence I agree it's not part
> of control plane.
>
> DNS is a protocol that builds the Name to IP address table. If CDP is part
> of the control plane which doesn't help much to operate the network then I
> feel DNS can also be part of control plane :-)
>
>
>
>
> With regards
> Kings
>
> On Tue, Nov 9, 2010 at 10:07 AM, Tyson Scott <[email protected]> wrote:
>
> Is DNS necessary, from a router perspective, for the network to operate?
>
>
>
> Control plane is only network services that "glue" the network together.
>
>
>
> Routing protocols,
>
>
>
> Regards,
>
>
>
> Tyson Scott - CCIE #13513 R&S, Security, and SP
>
> Managing Partner / Sr. Instructor - IPexpert, Inc.
>
> Mailto: [email protected]
>
> Telephone: +1.810.326.1444, ext. 208
>
> Live Assistance, Please visit: www.ipexpert.com/chat
>
> eFax: +1.810.454.0130
>
>
>
> IPexpert is a premier provider of Self-Study Workbooks, Video on Demand,
> Audio Tools, Online Hardware Rental and Classroom Training for the Cisco
> CCIE (R&S, Voice, Security & Service Provider) certification(s) with
> training locations throughout the United States, Europe, South Asia and
> Australia. Be sure to visit our online communities at
> www.ipexpert.com/communities and our public website at www.ipexpert.com
>
>
>
> *From:* Kingsley Charles [mailto:[email protected]]
> *Sent:* Monday, November 08, 2010 11:06 PM
> *To:* Tyson Scott
> *Cc:* Eugene Pefti; [email protected]
>
>
> *Subject:* Re: [OSL | CCIE_Security] DNS part of which plane
>
>
>
>
>
> Hi Tyson
>
> Can you please let me know the reason for having DNS in management plane.
> How does the DNS help to manage the deivce?
>
> I am not getting the picture.
>
> With regards
> Kings
>
> On Tue, Nov 9, 2010 at 8:08 AM, Tyson Scott <[email protected]> wrote:
>
> DNS is management plane.  It is not a service that glues the L3 network
> together.
>
>
>
> Regards,
>
>
>
> Tyson Scott - CCIE #13513 R&S, Security, and SP
>
> Managing Partner / Sr. Instructor - IPexpert, Inc.
>
> Mailto: [email protected]
>
> Telephone: +1.810.326.1444, ext. 208
>
> Live Assistance, Please visit: www.ipexpert.com/chat
>
> eFax: +1.810.454.0130
>
>
>
> IPexpert is a premier provider of Self-Study Workbooks, Video on Demand,
> Audio Tools, Online Hardware Rental and Classroom Training for the Cisco
> CCIE (R&S, Voice, Security & Service Provider) certification(s) with
> training locations throughout the United States, Europe, South Asia and
> Australia. Be sure to visit our online communities at
> www.ipexpert.com/communities and our public website at www.ipexpert.com
>
>
>
> *From:* [email protected] [mailto:
> [email protected]] *On Behalf Of *Eugene Pefti
> *Sent:* Sunday, November 07, 2010 3:23 AM
> *To:* 'Kingsley Charles'
>
>
> *Cc:* [email protected]
> *Subject:* Re: [OSL | CCIE_Security] DNS part of which plane
>
>
>
> That’s right. We see all ports that open on the router that belongs to the
> so-called host subinterface of Control Plane. What are debating about then ?
> ;)
>
> I didn’t find that DNS belongs to management plane in Cisco’s official
> documentation. Perhaps Yusuf in his flash cards is not right as the list of
> protocols mentioned in the Figure for this question is too big. Unless I
> confuse entirely the concept of Control and Management Plane
>
>
>
> *From:* Kingsley Charles [mailto:[email protected]]
> *Sent:* Sunday, November 07, 2010 12:56 AM
> *To:* Eugene Pefti
> *Cc:* [email protected]
> *Subject:* Re: [OSL | CCIE_Security] DNS part of which plane
>
>
>
> Eugene, the O/P is self explanatory. The show control-plane host openshows 
> all the port that the router is listening to. The
> O/P has port 22 and 23 which is ssh and telnet respectively. Does that mean
> telnet and ssh are control plane protocols?
>
> The O/P includes management, control and service protocol port numbers.
> ISAKMP is in service plane right, you can 500 and 4500 in the O/P too.
>
>
> With regards
> Kings
>
> On Sun, Nov 7, 2010 at 1:13 PM, Eugene Pefti <[email protected]>
> wrote:
>
> It’s a good point, Kings.
>
> Our customer uses their routers as DNS servers at their remote offices and
> the traffic destined to the router itself can be falling under the
> management plane.
>
> I thought that you control access to the router via a regular ACL which I
> still do by applying it to different VLAN interfaces.
>
> But when I query the router to show me open ports under the control plane I
> see DNS on the list as well. Hence DNS traffic is from control-plane ;)
>
>
>
> Router_LAB#show control-plane host open
>
> Active internet connections (servers and established)
>
> Prot               Local Address             Foreign
> Address                  Service    State
>
>  tcp                        *:22                         *:0
> SSH-Server   LISTEN
>
>  tcp                        *:23
> *:0                   Telnet   LISTEN
>
>  tcp                        *:53                         *:0
> DNS Server   LISTEN
>
>  udp                        *:53                         *:0
> DNS Server   LISTEN
>
>  udp                        *:67                         *:0
> DHCPD Receive   LISTEN
>
>  udp                      *:2887
> *:0                      DDP   LISTEN
>
>  udp                       *:123
> *:0                      NTP   LISTEN
>
>  udp                      *:4500
> *:0                   ISAKMP   LISTEN
>
>  udp                       *:500
> *:0                   ISAKMP   LISTEN
>
>
>
> *From:* [email protected] [mailto:
> [email protected]] *On Behalf Of *Kingsley Charles
> *Sent:* Saturday, November 06, 2010 11:52 PM
> *To:* [email protected]
> *Subject:* [OSL | CCIE_Security] DNS part of which plane
>
>
>
> Hi all
>
> As per the Yusuf flash cards, DNS is part of the Management plane.
>
> Management plane is used to manage the device and control plane is used to
> dynamically build the network.
>
> The DNS builds the network by resolving the FQDN to IP address.
>
> I think, DNS should be in the control plane list.
>
> Any thoughts?
>
> With regards
> Kings
>
>
>
>
>
>
>
> _______________________________________________
> For more information regarding industry leading CCIE Lab training, please
> visit www.ipexpert.com
>
>
>
> ---
>
> Nefkens Advies
>
> Enk 26
>
> 4214 DD Vuren
>
> The Netherlands
>
>
>
> Tel: +31 183 634730
>
> Fax: +31 183 690113
>
> Cell: +31 654 323221
>
> Email: [email protected]
>
> Web: http://www.nefkensadvies.nl/
>
>
>
>
>
>
>
>
>
>
>
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Reply via email to