Re: L3 Network topology in YANG

[Yannis Mitsos]

Hi Rob,

On 13:53 Wed 05 Dec , Rob Shakir wrote:

Hi Yannis,

I know that there are some folks using pyangbind with models that correspond to
topology including rfc8346, similarly, some folks are using goyang+ygot (where


Would be nice to contact them, if possible, and exchange some experiences.

Regards,

y.


using Go) for dealing with their topology models in YANG. I'm not clear how far
these operations are along, but I've handled feature requests related to these
models in both.

Cheers,
r.


On Mon, 19 Nov 2018 at 09:44 Yannis Mitsos  wrote:

   All,

   I was wondering if there is any network operator who exposes
   (dynamically?) its topology in YANG based on RFC8346 [1]. I understand
   that for commercial operators and purposes, may not be of any
   substantial value.
   We are assessing some available tools[2],[3],[4] on how to achieve this
   but we would like to know if there is any success story out there.

   Regards,

   Yannis

   [1] https://tools.ietf.org/html/rfc8346
   [2] https://github.com/robshakir/pyangbind
   [3] https://github.com/YangModels/yang.git
   [4] https://developer.cisco.com/site/ydk






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Re: L3 Network topology in YANG

[Rob Shakir]

Hi Yannis,

I know that there are some folks using pyangbind with models that
correspond to topology including rfc8346, similarly, some folks are using
goyang +ygot
 (where using Go) for dealing with their
topology models in YANG. I'm not clear how far these operations are along,
but I've handled feature requests related to these models in both.

Cheers,
r.


On Mon, 19 Nov 2018 at 09:44 Yannis Mitsos  wrote:

> All,
>
> I was wondering if there is any network operator who exposes
> (dynamically?) its topology in YANG based on RFC8346 [1]. I understand
> that for commercial operators and purposes, may not be of any
> substantial value.
> We are assessing some available tools[2],[3],[4] on how to achieve this
> but we would like to know if there is any success story out there.
>
> Regards,
>
> Yannis
>
> [1] https://tools.ietf.org/html/rfc8346
> [2] https://github.com/robshakir/pyangbind
> [3] https://github.com/YangModels/yang.git
> [4] https://developer.cisco.com/site/ydk
>
>
>
>
>

L3 Network topology in YANG

[Yannis Mitsos]

All,

I was wondering if there is any network operator who exposes
(dynamically?) its topology in YANG based on RFC8346 [1]. I understand
that for commercial operators and purposes, may not be of any
substantial value.
We are assessing some available tools[2],[3],[4] on how to achieve this
but we would like to know if there is any success story out there.

Regards,

Yannis

[1] https://tools.ietf.org/html/rfc8346
[2] https://github.com/robshakir/pyangbind
[3] https://github.com/YangModels/yang.git
[4] https://developer.cisco.com/site/ydk

Re: Network topology [Solved]

[John Kemp]

I know Carlos did a bunch of work to build this
into Netdot, i.e. discover L2, draw usable graphs.

Here's a link to the last NANOG presentation:

http://www.nanog.org/meetings/nanog49/presentations/Tuesday/Vicente-netdot-presentation-nanog49.pdf

John Kemp

On 10/15/08 7:18 PM, Dale W. Carder wrote:
 
 On Oct 15, 2008, at 1:35 PM, Colin Alston wrote:
 
 On 2008/10/15 06:29 PM Colin Alston wrote:
 Is there any kind of cunning trick to detect standard layer2 switches
 along a path without stuff like STP?

 Apparently there isn't. Lots of people mentioned other tools, the
 problem there is they have one thing in common which is polling SNMP.
 I think it scales badly in general.
 
 What is your reasoning behind this claim?  I would claim
 quite the opposite compared to CLI or TL1.
 
 Maybe there should be something (I mean like, someone should come up
 with a standard :P) to trace switches in a path
 
 I've written a cruddy script that given a seed bridge, scrapes
 L2 information obtained via CDP (I guess it could do LLDP, too)
 and does a breadth-first search through a network.  Then I just
 dump that into gnuplot format.  Getting the data is easy compared
 to visualization.
 
 A coworker of mine has written script to ask Rapid-STP speaking
 switches about their current topology and builds a graph again
 in gnuplot format.
 
 A more challenging approach would be to scrape the mac forwarding
 tables and stitch things together.  This would have to be done
 per-vlan.  I think this approach (or similar) might be done by
 Openview's L2 featureset.
 
 Dale
 
 -- 
 Dale W. Carder - Network Engineer
 University of Wisconsin / WiscNet
 http://net.doit.wisc.edu/~dwcarder
 
 

Re: Network topology [Solved]

[John Kemp]

Ah, sorry.  Resurrected an old one there...
;-/

/jgk

On 11/15/13 2:41 PM, John Kemp wrote:
 
 I know Carlos did a bunch of work to build this
 into Netdot, i.e. discover L2, draw usable graphs.
 
 Here's a link to the last NANOG presentation:
 
 http://www.nanog.org/meetings/nanog49/presentations/Tuesday/Vicente-netdot-presentation-nanog49.pdf
 
 John Kemp
 
 On 10/15/08 7:18 PM, Dale W. Carder wrote:

 On Oct 15, 2008, at 1:35 PM, Colin Alston wrote:

 On 2008/10/15 06:29 PM Colin Alston wrote:
 Is there any kind of cunning trick to detect standard layer2 switches
 along a path without stuff like STP?

 Apparently there isn't. Lots of people mentioned other tools, the
 problem there is they have one thing in common which is polling SNMP.
 I think it scales badly in general.

 What is your reasoning behind this claim?  I would claim
 quite the opposite compared to CLI or TL1.

 Maybe there should be something (I mean like, someone should come up
 with a standard :P) to trace switches in a path

 I've written a cruddy script that given a seed bridge, scrapes
 L2 information obtained via CDP (I guess it could do LLDP, too)
 and does a breadth-first search through a network.  Then I just
 dump that into gnuplot format.  Getting the data is easy compared
 to visualization.

 A coworker of mine has written script to ask Rapid-STP speaking
 switches about their current topology and builds a graph again
 in gnuplot format.

 A more challenging approach would be to scrape the mac forwarding
 tables and stitch things together.  This would have to be done
 per-vlan.  I think this approach (or similar) might be done by
 Openview's L2 featureset.

 Dale

 -- 
 Dale W. Carder - Network Engineer
 University of Wisconsin / WiscNet
 http://net.doit.wisc.edu/~dwcarder


 

Network topology

[Colin Alston]

Hi all

I'm considering trying to come up with some means to automatically 
detect a networks topology and draw pretty pictures. This is somewhat 
boring though if a network isn't well arranged with VLANs and q-tag 
trunk routers and so on (It will just look like a big cloud of junk 
connected off an assumed switch).


Is there any kind of cunning trick to detect standard layer2 switches 
along a path without stuff like STP?

Re: Network topology

[Bill Woodcock]

  On Wed, 15 Oct 2008, Colin Alston wrote:
 I'm considering trying to come up with some means to automatically detect
 a networks topology and draw pretty pictures.

InterMapper.  

http://dartware.com/network_monitoring_products/intermapper/index.html

-Bill

Re: Network topology

[Brian Feeny]

And another one, that I believe is a commercial product:

http://www.solarwinds.com/products/lansurveyor/


On Oct 15, 2008, at 12:29 PM, Bill Woodcock wrote:


 On Wed, 15 Oct 2008, Colin Alston wrote:
I'm considering trying to come up with some means to automatically  
detect

a networks topology and draw pretty pictures.


InterMapper.

   http://dartware.com/network_monitoring_products/intermapper/index.html

   -Bill

Re: Network topology

[Colin Alston]

On 2008/10/15 06:29 PM Bill Woodcock wrote:
InterMapper.  


http://dartware.com/network_monitoring_products/intermapper/index.html

-Bill



Whoa, quite a serious looking piece of software. Will check it out.

Was kinda hoping to write my own software though, but perhaps I can 
craftily learn something from it :)

Re: Network topology [Solved]

[Colin Alston]

On 2008/10/15 06:29 PM Colin Alston wrote:
Is there any kind of cunning trick to detect standard layer2 switches 
along a path without stuff like STP?


Apparently there isn't. Lots of people mentioned other tools, the 
problem there is they have one thing in common which is polling SNMP. 
I think it scales badly in general. I was hoping to find a more 
intelligent way of, I guess, doing an ARP/MAC based traceroute by 
checking LLC 802.2 headers or something. Yes, it might have been 
easier if I hoped for it to rain money :)


Maybe there should be something (I mean like, someone should come up 
with a standard :P) to trace switches in a path... Problem is I think 
even then the simple devices won't bother to support it.

Re: Network topology [Solved]

[Larry Sheldon]

Colin Alston wrote:

Maybe there should be something (I mean like, someone should come up 
with a standard :P) to trace switches in a path... Problem is I think 
even then the simple devices won't bother to support it.


I have been away from it for ma while and in truth don't know the 
answer--but--


To the best of my knowledge, Layer two Switches in fact operate as 
multi-port bridges.


If that is true, then they ought to be transmitting BDUs which should be 
detectable and used for mapping.


If the switches are all from the same manufacturer, there is a chance 
that the manufacture has a proprietary mapping tool.

--
Requiescas in pace o email  Two identifying characteristics
 of System Administrators:
Ex turpi causa non oritur actioInfallibility, and the ability to
 learn from their mistakes.
Eppure si rinfresca

ICBM Targeting Information: http://tinyurl.com/4sqczs

RE: Network topology [Solved]

[Holmes,David A]

If the switches are Cisco, then Cisco Works has a L2 STP forwarding path
graphical display which can be used in cases where the L3 path is a
logical abstraction overlaid on the underlying L2 topology.

-Original Message-
From: Larry Sheldon [mailto:[EMAIL PROTECTED] 
Sent: Wednesday, October 15, 2008 11:49 AM
Cc: NANOG list
Subject: Re: Network topology [Solved]

Colin Alston wrote:

 Maybe there should be something (I mean like, someone should come up 
 with a standard :P) to trace switches in a path... Problem is I think 
 even then the simple devices won't bother to support it.

I have been away from it for ma while and in truth don't know the 
answer--but--

To the best of my knowledge, Layer two Switches in fact operate as 
multi-port bridges.

If that is true, then they ought to be transmitting BDUs which should be

detectable and used for mapping.

If the switches are all from the same manufacturer, there is a chance 
that the manufacture has a proprietary mapping tool.
-- 
Requiescas in pace o email  Two identifying characteristics
  of System Administrators:
Ex turpi causa non oritur actioInfallibility, and the ability to
  learn from their mistakes.
Eppure si rinfresca

ICBM Targeting Information: http://tinyurl.com/4sqczs

Re: Network topology [Solved]

[Colin Alston]

On 2008/10/15 08:49 PM Larry Sheldon wrote:

Colin Alston wrote:

Maybe there should be something (I mean like, someone should come up 
with a standard :P) to trace switches in a path... Problem is I think 
even then the simple devices won't bother to support it.


I have been away from it for ma while and in truth don't know the 
answer--but--


To the best of my knowledge, Layer two Switches in fact operate as 
multi-port bridges.


If that is true, then they ought to be transmitting BDUs which should be 
detectable and used for mapping.


Ahh, you are correct sir (as well as the off list responses :))

Found this rather quickly

http://www.geocities.com/milicsasa/Tools/l2trace/index.html
as well as
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/l2trace.pdf

Not sure why I didn't Google layer 2 traceroute before... Oh well, 
live and learn, and work shorter hours.


Thanks :)

Re: Network topology [Solved]

[David W. Hankins]

On Wed, Oct 15, 2008 at 08:35:33PM +0200, Colin Alston wrote:
 Apparently there isn't. Lots of people mentioned other tools, the problem 
 there is they have one thing in common which is polling SNMP. I think it 
 scales badly in general. I was hoping to find a more intelligent way of, I 

I don't know what scaling parameters you're looking for.  The tool
I wrote to recursively traverse Cisco CDP caches via SNMP, from ~7
seed routers, autodetected the interconnections of a ~100 node network
(back in 1998) in just seconds (I think it was 3, but that was ten
years ago).

Using SNMP.

It didn't strain our P90 it was running on, nor the network.

People often do SNMP wrong (one PDU per packet, single-threaded
transmitters, etc).

 Maybe there should be something (I mean like, someone should come up with a 
 standard :P) to trace switches in a path... Problem is I think even then 
 the simple devices won't bother to support it.

Or if they do, they'll do it wrong.  They can't even get ifDescr
right.

-- 
Ash bugud-gul durbatuluk agh burzum-ishi krimpatul.
Why settle for the lesser evil?  https://secure.isc.org/store/t-shirt/
-- 
David W. HankinsIf you don't do it right the first time,
Software Engineeryou'll just have to do it again.
Internet Systems Consortium, Inc.   -- Jack T. Hankins


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Re: Network topology [Solved]

[Dale W. Carder]

On Oct 15, 2008, at 1:35 PM, Colin Alston wrote:


On 2008/10/15 06:29 PM Colin Alston wrote:
Is there any kind of cunning trick to detect standard layer2  
switches along a path without stuff like STP?


Apparently there isn't. Lots of people mentioned other tools, the  
problem there is they have one thing in common which is polling  
SNMP. I think it scales badly in general.


What is your reasoning behind this claim?  I would claim
quite the opposite compared to CLI or TL1.

Maybe there should be something (I mean like, someone should come  
up with a standard :P) to trace switches in a path


I've written a cruddy script that given a seed bridge, scrapes
L2 information obtained via CDP (I guess it could do LLDP, too)
and does a breadth-first search through a network.  Then I just
dump that into gnuplot format.  Getting the data is easy compared
to visualization.

A coworker of mine has written script to ask Rapid-STP speaking
switches about their current topology and builds a graph again
in gnuplot format.

A more challenging approach would be to scrape the mac forwarding
tables and stitch things together.  This would have to be done
per-vlan.  I think this approach (or similar) might be done by
Openview's L2 featureset.

Dale

--
Dale W. Carder - Network Engineer
University of Wisconsin / WiscNet
http://net.doit.wisc.edu/~dwcarder