[a-nsp] 7050SX MPLS ?

Patrik Olsson darkiesan at me.com
Tue Jan 26 15:17:08 EST 2021



> On 26 Jan 2021, at 18:03, Bryan Holloway <bryan at shout.net> wrote:
> 
> 
> On 1/26/21 12:27 PM, Mark Tinka wrote:
>> On 1/26/21 13:17, Patrik Olsson wrote:
>>> Arista switch ports have L2 jumbo frames by default (9214 bytes).
>>> 
>>> Routed ports (SVI and non switch ports) have default IP MTU 1500 bytes.
>>> 
>>> So the uplink between 7050SX and ASR9k need to be IP MTU enough to have room for any VLAN headers aswell as MPLS tags.
>>> 
>>> 7050SX only supports LDP L2circuits.
>> Because what the OP describes seems like an MTU issue on the interface that is running MPLS (physical or virtual).
>> Would raising that be the simple solution?
>> Mark.
> 
> Yeah, I've been bitten by that before ...
> 
> While the SVI /30 is IP MTU 1500, the L2 MTU (for tagging, MPLS, etc.) is 9200.
> 

You can raise the IP MTU, no problemo.

> Sounds like the 7050SX isn't hip enough to be a proper PE, which was my initial suspicion.
> 

L3VPN PE, no. 
L2VPN with BGP control plane PE, no.
Martini circuit PE, yes fully doable.

7050SX is Trident II chipset, so its Ok.





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