Re: multi ethernet cards for a squid cache

On Tue, Jul 06, 1999 at 11:15:24PM -0500, Jonathan Hall wrote:

> On Tue, 6 Jul 1999 jlewis@lewis.org wrote:
>
> > On Tue, 6 Jul 1999, Rob Harris wrote:
> >
> > > Has anyone figured out how to make squid use more than one ethernet card
> > > to retrieve objects into it's cache?
> >
> > This isn't a squid issue. It's a matter of convincing your system to use
> > both ethernet cards. Squid doesn't have anything to do with how packets
> > get routed.
>
> It can. Some proxy software packages (nntpcache, for instance) allows the
> admin to specify which network device requests are sent to. Makes for
> nice load balancing. In the case of nntpcache, you can tell it to get all
> alt.* groups over eth0 and all comp.* and misc.* groups from eth1, but
> still from the same news host.
>
> Although I don't believe squid has that functionality, it's not beyond the
> realm of possibility for that sort of system to exist.

You can bind to a specific address for outgoing TCP/IP traffic in squid
(tcp_outgoing_address), although it's an awkward concept.

Applications really have no place interfering with routing issues. In the
example you give above, what happens if you set up those bindings but the
address on eth1 turns out to be on a subnet that can't actually reach the
destination host? (Answer: it breaks).

This is tangential to what the original poster was asking, though. He needs
support to allow outgoing traffic sent to a specific address to be routed in
a round robin fashion across multiple interfaces. This can only be provided
in any sensible form by the operating system, since only the operating
system can tell which of the network interfaces it has configured can reach
that host, either directly or via a router.

Cheers

Chris

-- 
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Chris Tilbury, UNIX Systems Administrator, IT Services, University of Warwick
PHONE: 024 7652 3365 / FAX: 024 7652 3267 / MAIL: Chris.Tilbury@warwick.ac.uk