Subject: Loop prevention and detection

From: "Makarand Kulkarni (98307005) " <[email-masked]>
Date: Fri, 3 Sep 1999 15:35:27 +0530 (IST)

The shim header has a TTL field. Also while setting up a path we check 
for loops (ref. lsp-05 draft). I didn't understand why is it necessary to 
do prevention and detection . Or have I misinterpreted something

-- Makarand

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From: Eric Gray <[email-masked]>
Date: Fri, 03 Sep 1999 08:16:23 -0400

> do prevention and detection . Or have I misinterpreted something

Possibly.  What draft are you referring to as 'lsp-05'?

Loop prevention (checking for loops in LSP setup) was removed
from LDP because we did not decide which approach to use and 
it does not seem advisable to require support for both (which
would be needed since each relies on ubiquitous use in an LSP).

Looping data may be prevented from occurring using - for example
- ordered control, but even this works to prevent loops only if 
ubiquitous.

The TTL field is irrelevant in preventing or reducing looping
traffic in media where the shim header is not accessed at each
hop (for instance, ATM).