[j-nsp] vpls loop avoidance

[Keegan Holley]

Interesting.  It's a stack.  I guess I'll have to use multihoming. Just for
fun I'm going to see if I can get it to pass the untagged BPDUs.

Thanks,

Keegan

2011/10/12 Phil Bedard <philxor at gmail.com>

> Standards-based STP BPDUs are sent untagged, which might be an issue if
> the links to your CE switches are tagged only.  Cisco PVST+ sends the
> BPDUs with a VLAN tag.
>
>
> I remember seeing some blurb about not connecting two CE devices to each
> other if they are connected to two different PEs with the same site-id.
> Is this one switch or two?
>
>
> Phil
>
> On 10/11/11 4:14 PM, "Keegan Holley" <keegan.holley at sungard.com> wrote:
>
> >2011/10/11 Humair Ali <humair.s.ali at gmail.com>
> >
> >> Hi Keegan
> >>
> >> As far as I know , in VPLS, it uses split horizon as loop avoidance
> >> mechanism , and  you should not see any loop occurring in a VPLS
> >> setup,(pending the rest of config is correct)
> >>
> >
> >Yes it is BGP signaled so that will solve the loops on the core facing
> >interfaces.
> >
> >
> >>
> >> The only way you could have a loop in VPLS is when you start having
> >>your CE
> >> dual homed , where in that case you need to either configure STP , or
> >>you
> >> could use the primary/backup knob to define which PE is the primary and
> >> which is the back up.
> >>
> >
> >STP doesn't seem to work here.  Only cisco PVST which doesn't help me on
> >an
> >EX4200.  Primary/backup has to do with multihoming which works as well.
> >I'd
> >like to know why this works when the site-id's are the same and why the
> >l2forwarding instance doesn't work.  I'm also curious why cisco pvst works
> >and none of the standards based protocols.
> >
> >
> >
> >>
> >> On 11 October 2011 20:19, Keegan Holley <keegan.holley at sungard.com>
> >>wrote:
> >>
> >>> I'm trying to get my handle on vpls loop avoidance and I can't remember
> >>> the
> >>> default behavior regarding site-id's and node-id's.  I remember reading
> >>> about it in one config guide or another but I can't seem to find it
> >>>now.
> >>> I'm trying to remember if broadcast, multicast and unknown unicast is
> >>> flooded between PE router interfaces with the same site id's and maybe
> >>> just
> >>> some general guidelines on their behavior.  I'm trying to understand
> >>>best
> >>> practices for loop avoidance.  It seems to loop with any standards
> >>>based
> >>> STP
> >>> protocol if two or more interfaces are connected to routers configured
> >>> with
> >>> the same site-id.  The behavior I see seems to be the opposite of what
> >>>the
> >>> website says.
> >>>
> >>>
> >>>
> >>>
> http://www.juniper.net/techpubs/en_US/junos10.4/topics/concept/vpn-confi
> >>>guring-ethernet-switch-as-the-ce-device.html
> >>>  _______________________________________________
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> >>> https://puck.nether.net/mailman/listinfo/juniper-nsp
> >>>
> >>
> >>
> >>
> >> --
> >> Humair
> >>
> >>
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