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Hello,
On Fri, 3 Nov 2000, Laurent Lefoll wrote:
> Hi,
>
> I installed LVS some weeks ago with to real servers (mail servers) and
> it works properly but under some conditions, when the load increase I
> sometimes got a "kernel: IP_MASQ: ip_masq_new(proto=UDP): could not get
> free masq entry (free=36692)". The UDP entries are in my case the result
> of lots of DNS queries.
> What does it mean exactly ? Lack of memory or not enough "available"
> ports to create new entries ? What does mean the "(free=xxxx)" in the
> error messages ?
Not enough ports. free=36692 means 4268 used UDP entries from
total of 40960. But there is another implicit limit of 4096 connections
to one external service.
> I think I read somewhere that, by default, for LVS the first usable port
> is 61000 and that only 4096 simultaneous entries can be created. But it
> sounds strange to me because from what I understand in some discussions,
> it seems to be much more than that ! What am I misunderstanding and what
> should I tune ?
Yes, from the masq box to any external service can exit up to
4096 masqueraded "connections". Is the DNS server running on external
host? If yes, try to run internal DNS server, for example, on the masq
box.
> Regards,
>
> Laurent Le Foll
Regards
--
Julian Anastasov <ja@xxxxxx>
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