Ali -
There will always be a brief period of time immediately following the
failure when R1 will blithely continue to forward packets oblivious to the
loss of the R4. How long that period of time will be depends on which
routing protocol the routers are implementing and how the protocols are
configured. "Modern" routing protocols (e.g., EIGRP, OSPF) can detect such a
failure in a matter of seconds. Older routing protocols (e.g., RIP) could
take a couple to a few minutes.
/Michel
-----Original Message-----
From: Ali Boudani [mailto:aboudani(_at_)irisa(_dot_)fr]
Sent: Wednesday, February 13, 2002 6:49 AM
To: ietf(_at_)ietf(_dot_)org
Subject: Simple question
If we have the following figure:
R1---------R2---------R3---------R4 where R1 to R4 are unicast routers.
R1 is sending packets to R4. If R4 goes down, when R1 will detect this??
Before sending packets or after?