RS/960 upgrade ... status report

William Manning bmanning at
Fri May 1 04:07:02 UTC 1992

Mark said:
observed during RS/960 testing. The problem involved some aberrant
behavior of rcp_routed when a misconfigured regional peer router would
advertise a route via BGP to an ENSS whose next hop was the ENSS
itself. The old rcp_routed could go into a loop sending multiple
redirect packets out on to the subnet. The new rcp_routed will close
the BGP session if it receives an announcement of such a route.  The
new rcp_routed software also has support for externally administered
inter-AS metrics, an auto-restart capability, and bug fixes for BGP
overruns with peer routers.

        This deployment caused a few problems. One is that this
new feature of rcp_routed pointed out a misconfigured peer router
at Rice University in Houston. This caused the BGP connection to
open and close rapidly which caused further problems on the peer
router. Eventually the peer was reconfigured to remove the
bad route, which fixed the problem. Another problem was on the
Argonne ENSS. This node crashed in such a way that it was


What he did not say:

	The new rcp_routed will (virtually) immeadiately after the close,
reopen a BGP session and pump all known routes at the BGP peer. If the
peer is already  working on processing the old ones, this adds an unneeded
burden on the regional peer.  I have not reviewed the spec in detail,
but there should be something in place to prevent a constant cycle of
close, open, slam 5k routes, close, open, slam 5k routes, close...
well, you get the picture. This points out a configuration problem with 
BGP in the ANS T3 routers, in addition to the less than optimal configuration
that we had in our ciscos.  

Just my two cents from the other side of the fence.
Bill Manning         bmanning at        PO Box 1892
 713-285-5415         713-527-6099	       Houston, Texas
   R.U. (o-kome)       			        77251-1892

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