[c-nsp] T3 or Ethernet delivery?

[Gert Doering]

Hi,

On Wed, Apr 08, 2009 at 12:14:52AM -0700, Seth Mattinen wrote:
> How do you detect a "down" condition on Ethernet? My experience is that
> the interface could be up/up because Ethernet doesn't know about
> anything further down the line and ends up throwing packets into a
> magical black hole. Or worse, secret packet loss.

Run a routing protocol over it.

[..]
> With a T3 I can be fairly certain that if there aren't any alarms that
> my end is happily talking to the other end. How does one accomplish the
> same with Ethernet? A periodic "ping" seems rather ambiguous as a health
> check.

Not necessarily so - even on a T3, you can have bad cables going just
one way, so you might have packet loss in your transmit direction.  The
provider would see (CRC) errors, but you might not see anything.

So you'll need to run ping...

(And yes, I know how you feel.  But the price difference between the
gear for SDH 2.4 Gbit equipment vs. 2 x 1Gbit ethernet links was so
overwhelming that we decided to go for ethernet... and for the same
price, we even got *two* links, so "no single point of failure")

gert
-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 304 bytes
Desc: not available
URL: <https://puck.nether.net/pipermail/cisco-nsp/attachments/20090408/5bab79ca/attachment.bin>