The MPLS-OPS Archive

[Wulf Losee <qx49@attbi.com>]

Tarun:
You didn't mention what sort of routers you're using. But I know that
both Cisco and Juniper offer a way to change the MTU value on the
Ethernet interfaces. On Cisco it's 'tag-switching mtu 1504' (actually,
1504 sounds too small, but it's past my bedtime, and I don't have the
patience to think it through ;-). And I'm afraid I don't remember the
syntax for Juniper. 

As I recall Cisco actually allows MTU values of up to 1526 -- maybe
that's why I think the 1504 is too small. Push it up to 1526...

If you don't have Cisco or Juniper, it *may* be that the brand of router
you're using doesn't support a similar command -- but I think they'd have
to! Check your manual...

cheers,
--Wulf

At 10:11 AM 3/21/03 -0800, Tarun Bhalla wrote:
> hi
> all,
>  
> I am new to this mailing list. so hi to all..
> now my problems :(( 
> Actually, I am trying to handle the problem of
> fragmentation in 
> Ethernet over MPLS network.
>  
> This is the existing network
> topology...
>  
> LAN A -------> MPLS Domain
> ----------> LAN B
>  
> To implement EoMPLS, I am capturing the packet in Ingress of the MPLS domain
> and trying to send this as a payload over the MPLS domain.. When I 
> am doing this the problem is that the frames which are 1500 bytes (normal
> ethernet frames) can not be sent across this MPLS domain as the payld
> of this domain can only be 1496 bytes... (4 bytes label gets added and leave
> the matter when multiple labels are added).. So, I am stuck as i am not
> able to send 1500 bytes frames.. 
>  
> These all things are being carried on test setups. So, I can not
> have the liberty or leisure to use SONET interfaces as my core n/w 
> interfaces.. also am not sure what to do in order to make use of jumbo
> ethernet frames... So, the only option left is to fragment the frames when i 
> capture the ethernet frames.. but for that i need ur advice.. 
>  
> I mean is there any standard methodology that says how to handle 
> fragmentation in ethernet layer cos I will have to anyway go to this 
> final resort.. or is there any other way arnd. ?? 
>  
> Thanks & Regards
> Tarun B
> _________________________________________________
> Tarun Bhalla
> Wipro Technologies
> 26 Hosur Main Road, 
> Bommanahalli,
> Bangalore- 560 068. India
> Tel +91-80-5732293, Extn 3139 <http://www.wipro.com/> 
>  
>