[c-nsp] VRF question

[Rodney Dunn]

<snip>
 > Depending on what IP features are lost it might be a better approach
 > to run a hybrid MPLS backbone where you might leave Internet traffic
 > as IP switched (untagged) and label switch L2/L3-VPNs, for example.

>There is no way to run some packages untagged and some tagged on the
>same interface. What you probably is thinking of is running the internet
>service in the global address space (one label) and L2/L3 VPNs on top of
>MPLS (two or more labels). This would work fine without any expansion of
>IP-adresses.
<snip>


Assuming you meant in your first sentence to say packets that's not
true.  You can easily have some tagged and some untagged packets
going out the same interface.  You could create a dual loopback
configuration with IPV4 peering and VPNV4 peering and then just
block tags from being advertised for the IPV4 sessions that
carry the internet routes.  That way your internet traffic is
never tagged in the core. I'm pretty sure that's the way some
customers did it when they didn't want their internet traffic
MPLS in the core. 


Rodney



On Mon, Oct 11, 2004 at 09:36:58AM +0200, Per Carlson wrote:
> On 2004-10-08 18:42, dave bernardi wrote:
> > So for those service providers running a (native?) MPLS backbone you'd 
>  > likely carry your global internet routing table in a VRF
> 
> I'd not recommend running a global internet routing table in a VRF. In a 
> VRF, all prefixes are prepended with a 64-bit RD creating 96-bit 
> prefixes. Doing that with a full internet routing table will eat your 
> memory.
> 
> > From what I can tell most IP features would still be available by the IP 
> > edge functionality of your router (7600 platform) even if it is also the 
>  > PE, correct?
> 
> That's very dependent of the type of cards you've got in the 7600. We
> have seen examples where you can apply an ACL to a interface, but it's
> not used at all (classic ge-wan osm).
> 
> > Depending on what IP features are lost it might be a better approach 
>  > to run a hybrid MPLS backbone where you might leave Internet traffic
>  > as IP switched (untagged) and label switch L2/L3-VPNs, for example.
> 
> There is no way to run some packages untagged and some tagged on the 
> same interface. What you probably is thinking of is running the internet 
> service in the global address space (one label) and L2/L3 VPNs on top of 
> MPLS (two or more labels). This would work fine without any expansion of 
> IP-adresses.
> 
> > How many of you are running a native MPLS backbone and was the major 
>  > determining factor VPN, QoS, or other?
> 
> MPLS don't give you any (apparent) advantages beyond the ability to 
> enable new types of services, like L2/L3-VPNs. That's the only reason we 
> are using MPLS today.
> 
> Per
> 
> 
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