Santosh P K wrote:
Hi Padma,
When you said its a "logical construct like VL and it is always
a p2p" you mean the underlaying link is always P2P link? If it is an
P2P link then PE's should be connected directly not by inbetween P
routers right ?
I am getting confused with this P2P link. Can you please explain
this?
A Virtual Link is a p2p interface as far as OSPF is concerned regardless
of the
nature of the physical interfaces used to forward the protocol packets.
Hence, a VL can span over a mix of p2p and broadcast interfaces and yet is
still a p2p for OSPF.
What I mean by logical construct is that only OSPF knows about a Virtual
Link
interface. A virtual like network type is not configurable and is always
a p2p.
Sham links are a logical internal OSPF interface (construct) similar to VL.
It can span over any physical media but from an OSPF perspective it is a
p2p.
Hope this helps
Padma
On 3/20/07, Padma Pillay-Esnault <[EMAIL PROTECTED]> wrote:
Abhay D.S wrote:
> Yes forwarded by routers.
>
> Well, about the demand circuit part I suggest you dont follow the RFC,
> since it may or may not be treated as DEMAND circuit.(It is a
requirement
> of the network to treat it as demand circuit, for example if you have
> heavy load
> of traffic on sham link then you can treat it as DC(demand circuit).
>
> If you really want to use sham link optimally, you can just increase
> the hello timeout
> on the sham links to be large and then let it be a proper p2p link. It
> is similar to hello
> suppression..
>
> --Abhay
>
> Santosh P K wrote:
>> Hi Abhay,
>>
>> Thanks. Are OSPF control packts just forwarded by P routers on
>> sham link ? RFC 4577 says that Sham link is treated as OSPF demand
>> circuit. In case of broad cast or NBMA configured as demand circuit
>> hello are not supressed as per RFC 1793 section 3.2. that means hello
>> are also forwarded to the endpoint just as OSPF control packets by P
>> router on sham link?
Sham link is a logical construct like VL and it is always a p2p.
Thanks
Padma
>>
>> Thanks and regards
>> Santosh P K
>>
>>
>> On 3/20/07, Abhay D.S <[EMAIL PROTECTED]> wrote:
>>> It is a SHAM...:-).
>>>
>>> Only sham link end point needs to be enabled in OSPF and
reachable over
>>> the multi hop
>>> network by BGP or static means.
>>>
>>> Means Sham Link end points must be routable over the network for
it to
>>> become UP.
>>>
>>> Santosh P K wrote:
>>> > Hi All,
>>> > I have some doubts on sham link. If a sham link is configured
>>> > between two PE's which are connected by many P routers in IP
backbone
>>> > , then is it nessary for all the P routes to run OSPF.
>>> > As per cisco user guid it is mentioned that
>>> > sham link is treated as virtual link. In case of virtual link
>>> > inbetween routers need to know OSPF protocol.
>>> >
>>> >
>>> > Thanks and regards
>>> > Santosh P K
>>> >
>>> > _______________________________________________
>>> > OSPF mailing list
>>> > [email protected]
>>> > https://www1.ietf.org/mailman/listinfo/ospf
>>> >
>>> >
>>>
>>>
>>
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>>
>
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