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Re: dropped routing socket messages...

In article <>,
J.T. Conklin <> wrote:
>I have a system that uses a user-space routing table implementation.
>It uses the kernel routing table as a forwarding table, and installs
>and removes routes as needed by the higher level routing policy.  It
>also opens a routing socket and monitors it for addresses being added
>and deleted from interfaces, interface link state, etc.
>Occasionally (less than 1% of system restarts), it seems that routing
>table events are being lost which results in my user-space routing
>table getting out of sync with reality.
>Under what circumstances would this happen? My initial hypotheses were
>that the either kernel couldn't allocate an mbuf for the event, or the
>routing socket receive buffer wasn't large enough and the even was
>dropped then.  But I don't see any "requests for memory denied" in 
>the mbuf stats (netstat -m); and I've set the socket buffer size to
>128K, and the total number of events is way lower than that.
>Is there any other likely reasons where routing socket events would 
>be dropped?  FWIW, this is a NetBSD-4 kernel.

No, I don't know but I would add some debugging code in the error paths.


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