Re: BFD over p2p transport links

[Phil Bedard <bedard.phil () gmail com>]

We use it on all of our links which are generally over our own DWDM/dark fiber network.  All links are 10G LAN PHY.  
Our DWDM systems propagate link failures but one of the main reasons we implemented it was our router vendors did not 
drop link during reboots during software upgrades.  GR wasn't supported in those cases.  We have had some issues with 
false positives but overall it has been running fairly stable for over a year.  I've found the same issue with another 
router vendor where after an upgrade you may have to reload a line module, and the module does not drop link during a 
reload... 

Phil 

On Feb 5, 2010, at 9:45 AM, Serge Vautour wrote:

> Hello,
>
> I'm being asked to look into using BFD over our P2P transport links. Is anyone else doing this? Our transport links 
> are all 10G Ethernet (LAN-PHY). There's no alarming inside of LAN-PHY like there is in SONET. The transport side 
> should propagate a fiber break by stopping to send light on both ends. This is enough to cause the router interfaces 
> to drop and for protocols to converge. 
>
> Since LAN-PHY doesn't have any built end-end alarming, some folks believe that we may encounter situations where a 
> fiber break doesn't cause interfaces do go down. Convergence would then have to wait for IGP hellos to detect the 
> problem. 
>
> Is anybody else running BFD over 10G LAN-PHY transport links? Any comments around BFD for this application in general?
>
> Thanks,
> Serge
>
>
>
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