Re: transparent-proxy

Alteon's layer 2 gigabit ethernet switch can also be configured to do
limited layer 4 processing, ie, the forwarding decision is made with
the source or destination ip address AND layer 4 port number, not with
the destination MAC address. Useful for such things as distributing
the load among a group of servers or redirecting HTTP requests to a
cache farm. It is not routing.

Sys Admin writes:
> Just a note,
>
> Yes, a switch only looks at layer 2 info, port numbers are layer 3... and
> switches are layer 2 devices...but, You can buy a Cisco Catalyst 5500
> SWITCH and put in a RSP card... Route Switch Processor, a router on a
> card.. with this configuration, the box is a switch, that has a router on
> a card that does layer3 off of the backplane.

I won't argue the difference between a bridge and a switch, but port
numbers appear in the layer 4 header.

Gone are the days of just layer 2 switching.

John

 
> Curtis
>
> On Wed, 10 Dec 1997, Bill Wichers wrote:
>
> > Don't you mean routers instead of switches? I'm not aware of any Ethernet
> > switches that have the ability to switch packets based on protocol type.
> > If these really are Ethernet switches, please pass along the manufacturer
> > and model number(s) by email. I'd be most interested in finding out more
> > about them...
> >
> > -Bill
> >
> > On Tue, 9 Dec 1997, John Taylor wrote:
> >
> > >
> > >
> > > I'm adding a feature to our ethernet switches that hopefully will
> > > allow for very fast transparent proxies.
> > >
> > > Our switches can be configured to direct all HTTP traffic on any port
> > > to a specific machine or group of machines, the squid servers. The
> > > destination MAC address of each HTTP packet is mapped to the MAC
> > > address of one of the squid servers and forwarded to that server. If
> > > all squid servers are down, the packets are forwarded normally.
> > >
> > > Thanks,
> > > John
> > >
> > >
> > >
> > >
> >
>
Received on Thu Dec 11 1997 - 09:06:00 MST