the TCP MSS resource exhaustion commit

Thorsten Greiner thorsten at
Fri Jan 9 05:25:24 PST 2004

* Andre Oppermann <andre at> [2004-01-09 11:34]:
> You can simply increase net.inet.tcp.minmssoverload to any
> higher value.  I suggest 2,000 as next step.  If set it to
> 0 the check will be disabled entirely.

Setting net.inet.tcp.minmssoverload to 4000 fixed my problem(s).

> This makes we wonder why the Oracle database server is sending
> so many small packets.  Is your JBoss application doing connection
> pooling (eg. multiplexing multiple SQL sessions over one tcp
> session)?

It performs connection pooling on the application layer, i.e. it
opens several connections and pools them to avoid reopening them. As
far as I understand each Oracle connection is associated with a TCP
connection - there is no pooling on the TCP level.

While I have read your commit message thoroughly I am not sure I
have understood the consequences of the new mechanism. Will the
exchange of many small packets trigger a connection drop?

Best regards


Never attribute to malice what can adequately be explained by

This message is digitally signed. To verify its integrity, download a copy
of GnuPG for your operating system from .
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url :

More information about the freebsd-current mailing list