Re: local routing problems

[Padraig Brady <padraig@xxxxxxxxxxxxx>]

Julian Anastasov wrote:

>         Hello,
>
> On Tue, 15 Jan 2002, Padraig Brady wrote:
>
>
> > >         The trick you are trying works only when the port
> > > is preserved, you can't alter the port. I'm not sure whether
> > > ipvsadm should return error on such setup.
> > Ah it is a trick :-)
> >
> > If you add the 127.0.0.1:port and also specify masq (-m)
> > it retains the port like I demonstrated before, but
> > if you dont specify -m it changes the port to be the
> > same as the virtualservice like you say is required.
>         Yes, because only the NAT mode alters addresses/ports
> in the packet. All other 3 methods don't change them
> nor localnode performs port redirection like the ipchains
> redirection. For LocalNode LVS just passes the packet to
> the upper layers, without change.
>
>
> > So ipvsadm should at least be consistent in changing
> > the port in both cases and ALSO it should print a warning
> > saying it has done so.
>         What I saw in your previous posting looks like a
> problem: ipvsadm allows real server with localnode method
> to have port different from the virtual server's port.
>
>
> > As you say the following does work:
> >
> > TCP  172.24.1.156:112 lc
> >   -> 127.0.0.1:112                  Local   1      0          2
> >
> > A small point is the server must bind(INADDR_ANY). Binding to
> > 127.0.0.1 or 172.24.1.156 alone does not work?
>         Hm, I assume that it should work with binding to ANY or
> with VIP.
>
>
> > Also for completeness, this does not work (connection refused):
> >
> > TCP  172.24.1.156:112 lc
> >   -> 172.24.1.156:112               Local   1      0          0
>         I assume your service is listening correctly on
> .156:112 or I'm missing something?

Yes it is listening correctly I think, let me double check...
Feck! sorry. Listening to 127.0.0.1 or VIP alone should work fine.
Don't mind me, stupid bug in my server.


> > What I'm trying to do is create a fallback realservice on the
> > director machine that can be added into any virtualservice as
> > appropriate, for e.g. to display a "sorry page" to a web client.
> > Any ideas?
>         With localnode this real server can run only on the VIP/ANY:VPORT.

That's awkward, as it would be very handy to have a server
listening on 127.0.0.1:some_port. So what I will have to do is have
the server listening to 127.0.0.1:all_VPORTs (which subsequently has
to dynamically change the ports it listens on), Feck..

Thank you very much
for the info,

Padraig.