Login | Register For Free | Help
Search for: (Advanced)

Mailing List Archive: Cisco: NSP

/31 on a PTP Ethernet interface

  

 
Cisco nsp RSS feed   Index | Next | Previous | View Threaded


lists.james.edwards at gmail

Mar 8, 2010, 8:32 AM

Post #1 of 16 (1404 views)
Permalink
/31 on a PTP Ethernet interface
This message prints every time this router boots that I am about to deploy.
The Ethernet is for Metro Ethernet, a PtP VLAN between 2 locations across
Qwest's QMOE cloud.
Config looks like this:

!
interface GigabitEthernet0/0/0
description QMOE service
no ip address
negotiation auto
!
interface GigabitEthernet0/0/0.1
description PtP VLAN to XXX
encapsulation dot1Q 10
ip address XXX.XXXXXX.8 255.255.255.254
ip access-group XXX out
no cdp enable
service-policy output QMOE-SHAPE

Can I get away with a /31, to save some IP space, or do I need a /30 ?


--
James H. Edwards
Senior Network Systems Administrator
Judicial Information Division
jedwards [at] nmcourts
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


linux.yahoo at gmail

Mar 8, 2010, 9:02 AM

Post #2 of 16 (1375 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
You needn't /30 anymore, rfc3021 is well suported for a while ;)
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


p.mayers at imperial

Mar 8, 2010, 9:33 AM

Post #3 of 16 (1372 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On 08/03/10 16:32, james edwards wrote:
> This message prints every time this router boots that I am about to deploy.

You didn't say which message but I'm guessing you mean the "Use a /31 on
a non-ptp carefully"

We use /31 on ethernet p2p on 6500/sup720 extensively. It works fine,
we've had no problems.
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


peter at rathlev

Mar 8, 2010, 9:36 AM

Post #4 of 16 (1374 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On Mon, 2010-03-08 at 18:02 +0100, Manu Chao wrote:
> You needn't /30 anymore, rfc3021 is well suported for a while ;)

But ethernet isn't point-to-point, so RFC 3021 doesn't cover it. It
might work, but it isn't standardised.

--
Peter


_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


Grzegorz at Janoszka

Mar 8, 2010, 9:36 AM

Post #5 of 16 (1369 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On 8-3-2010 18:02, Manu Chao wrote:
> You needn't /30 anymore, rfc3021 is well suported for a while ;)

And what with ospf and /31?

--
Grzegorz Janoszka
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


lists.james.edwards at gmail

Mar 8, 2010, 9:55 AM

Post #6 of 16 (1376 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On Mon, Mar 8, 2010 at 10:33 AM, Phil Mayers <p.mayers [at] imperial>wrote:

> On 08/03/10 16:32, james edwards wrote:
>
>> This message prints every time this router boots that I am about to
>> deploy.
>>
>
> You didn't say which message but I'm guessing you mean the "Use a /31 on a
> non-ptp carefully"
>
>

Sorry about that, yep that is what it says:

% Warning: use /31 mask on non point-to-point interface cautiously

--
James H. Edwards
Senior Network Systems Administrator
Judicial Information Division
jedwards [at] nmcourts
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


sethm at rollernet

Mar 8, 2010, 10:13 AM

Post #7 of 16 (1370 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On 3/8/10 9:02 AM, Manu Chao wrote:
> You needn't /30 anymore, rfc3021 is well suported for a while ;)

Cisco supports it fine, but not all vendors do. I don't have any
Foundry/Brocade stuff so this is secondhand, but someone on NANOG said
they didn't support /31's on Ethernet.

~Seth
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


sthaug at nethelp

Mar 8, 2010, 10:36 AM

Post #8 of 16 (1367 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
> You needn't /30 anymore, rfc3021 is well suported for a while ;)

Yes, RFC 3021 is well supported on *actual* point to point links (e.g.
SDH/SONET). Ethernet is *not* such a type of link.

There are lots of people who use /31 on Ethernet links without any
apparent problems. However ...

Some of us have tried (hard) to get Cisco and Juniper to come forward
with an official statement about whether /31 is supported or not on
Ethernet links. We have been entirely unsuccessful - the answer we
receive is always of the type "try it, it may work for you". That is
not "well supported" by my definition of the word.

Steinar Haug, Nethelp consulting, sthaug [at] nethelp
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


lists at hojmark

Mar 8, 2010, 11:18 AM

Post #9 of 16 (1371 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On Mon, 08 Mar 2010 10:13:00 -0800, you wrote:

> Cisco supports it fine, but not all vendors do. I don't have any
> Foundry/Brocade stuff so this is secondhand, but someone on NANOG said
> they didn't support /31's on Ethernet.

One platform that doesn't support it is PacketFront ASR routers.
AFAIK, they have no plans to begin to do that.

-A

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


linux.yahoo at gmail

Mar 8, 2010, 11:32 AM

Post #10 of 16 (1373 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
Ethernet is not designed for p2p but can be used for this purpose.
OSI allow any L3 over L2 Ethernet, there is no issue with IPv4 @

2010/3/8, sthaug [at] nethelp <sthaug [at] nethelp>:
>> You needn't /30 anymore, rfc3021 is well suported for a while ;)
>
> Yes, RFC 3021 is well supported on *actual* point to point links (e.g.
> SDH/SONET). Ethernet is *not* such a type of link.
>
> There are lots of people who use /31 on Ethernet links without any
> apparent problems. However ...
>
> Some of us have tried (hard) to get Cisco and Juniper to come forward
> with an official statement about whether /31 is supported or not on
> Ethernet links. We have been entirely unsuccessful - the answer we
> receive is always of the type "try it, it may work for you". That is
> not "well supported" by my definition of the word.
>
> Steinar Haug, Nethelp consulting, sthaug [at] nethelp
>

--
Envoyé avec mon mobile

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


sthaug at nethelp

Mar 8, 2010, 12:21 PM

Post #11 of 16 (1367 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
> Ethernet is not designed for p2p but can be used for this purpose.
> OSI allow any L3 over L2 Ethernet, there is no issue with IPv4 @

Sure. And we use Ethernet as point to point technology too. However,
that is an entirely different statement than saying that /31 is "well
supported" on Ethernet.

Steinar Haug, Nethelp consulting, sthaug [at] nethelp

> 2010/3/8, sthaug [at] nethelp <sthaug [at] nethelp>:
> >> You needn't /30 anymore, rfc3021 is well suported for a while ;)
> >
> > Yes, RFC 3021 is well supported on *actual* point to point links (e.g.
> > SDH/SONET). Ethernet is *not* such a type of link.
> >
> > There are lots of people who use /31 on Ethernet links without any
> > apparent problems. However ...
> >
> > Some of us have tried (hard) to get Cisco and Juniper to come forward
> > with an official statement about whether /31 is supported or not on
> > Ethernet links. We have been entirely unsuccessful - the answer we
> > receive is always of the type "try it, it may work for you". That is
> > not "well supported" by my definition of the word.
> >
> > Steinar Haug, Nethelp consulting, sthaug [at] nethelp
> >
>
> --
> Envoyé avec mon mobile
>

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


linux.yahoo at gmail

Mar 8, 2010, 12:29 PM

Post #12 of 16 (1382 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
I agree, /31 well supported on carrier class router. As you say, rfc
may need an update for ethernet p2p

2010/3/8, sthaug [at] nethelp <sthaug [at] nethelp>:
>> Ethernet is not designed for p2p but can be used for this purpose.
>> OSI allow any L3 over L2 Ethernet, there is no issue with IPv4 @
>
> Sure. And we use Ethernet as point to point technology too. However,
> that is an entirely different statement than saying that /31 is "well
> supported" on Ethernet.
>
> Steinar Haug, Nethelp consulting, sthaug [at] nethelp
>
>> 2010/3/8, sthaug [at] nethelp <sthaug [at] nethelp>:
>> >> You needn't /30 anymore, rfc3021 is well suported for a while ;)
>> >
>> > Yes, RFC 3021 is well supported on *actual* point to point links (e.g.
>> > SDH/SONET). Ethernet is *not* such a type of link.
>> >
>> > There are lots of people who use /31 on Ethernet links without any
>> > apparent problems. However ...
>> >
>> > Some of us have tried (hard) to get Cisco and Juniper to come forward
>> > with an official statement about whether /31 is supported or not on
>> > Ethernet links. We have been entirely unsuccessful - the answer we
>> > receive is always of the type "try it, it may work for you". That is
>> > not "well supported" by my definition of the word.
>> >
>> > Steinar Haug, Nethelp consulting, sthaug [at] nethelp
>> >
>>
>> --
>> Envoyé avec mon mobile
>>
>

--
Envoyé avec mon mobile

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


ltd at cisco

Mar 8, 2010, 1:43 PM

Post #13 of 16 (1365 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On 09/03/2010, at 5:36 AM, sthaug [at] nethelp wrote:

> Some of us have tried (hard) to get Cisco and Juniper to come forward
> with an official statement about whether /31 is supported or not on
> Ethernet links. We have been entirely unsuccessful - the answer we
> receive is always of the type "try it, it may work for you". That is
> not "well supported" by my definition of the word.

i can't speak for other platforms but those that run NX-OS have supported /31 on ethernet point-to-point interfaces from day one and it IS officially supported.

ltd-n7010-1(config-if)# int eth1/2
ltd-n7010-1(config-if)# ip address 2.1.1.1/31
ltd-n7010-1(config-if)#



cheers,

lincoln.


_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


jmayer at loplof

Mar 8, 2010, 2:44 PM

Post #14 of 16 (1365 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On Mon, Mar 08, 2010 at 10:13:00AM -0800, Seth Mattinen wrote:
> On 3/8/10 9:02 AM, Manu Chao wrote:
> > You needn't /30 anymore, rfc3021 is well suported for a while ;)
>
> Cisco supports it fine, but not all vendors do. I don't have any
> Foundry/Brocade stuff so this is secondhand, but someone on NANOG said
> they didn't support /31's on Ethernet.

That's the info too, that I got from a B/F SE: While they support opsf
p-2-p on Ethernet, they do not support /31.

Ciao
Joerg
--
Joerg Mayer <jmayer [at] loplof>
We are stuck with technology when what we really want is just stuff that
works. Some say that should read Microsoft instead of technology.
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


ras at e-gerbil

Mar 8, 2010, 4:01 PM

Post #15 of 16 (1365 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
On Mon, Mar 08, 2010 at 11:44:06PM +0100, Joerg Mayer wrote:
> That's the info too, that I got from a B/F SE: While they support opsf
> p-2-p on Ethernet, they do not support /31.

Not only do they not support it, but the last time I tried it (a couple
years ago on modern platforms but not current code) it actually broke
stuff if you learned a /31 route over a routing protocol. One reason
among many why all my our Floundry's got the boot from all non-L2 roles.
:)

--
Richard A Steenbergen <ras [at] e-gerbil> http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


lsawyer at gci

Mar 8, 2010, 4:01 PM

Post #16 of 16 (1371 views)
Permalink
Re: /31 on a PTP Ethernet interface [In reply to]
Joerg Mayer replies
> On Mon, Mar 08, 2010 at 10:13:00AM -0800, Seth Mattinen wrote:
> > On 3/8/10 9:02 AM, Manu Chao wrote:
> > > You needn't /30 anymore, rfc3021 is well suported for a while ;)
> >
> > Cisco supports it fine, but not all vendors do. I don't have any
> > Foundry/Brocade stuff so this is secondhand, but someone on
> > NANOG said they didn't support /31's on Ethernet.
>
> That's the info too, that I got from a B/F SE: While they
> support opsf p-2-p on Ethernet, they do not support /31.

For what it's worth:

ISIS works quite happily with a /31 on ethernet PTP.


_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

Cisco nsp RSS feed   Index | Next | Previous | View Threaded
 
 


Interested in having your list archived? Contact Gossamer Threads
 
  Web Applications & Managed Hosting Powered by Gossamer Threads Inc.