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#1 (**permalink**) 01-16-2008, 08:35 AM

Hi,

I have a V240 connected to two different subnets, and I want to be able
to specify a different default route for each interface. If I don't
have a /etc/defaultrouter I end up with

default 163.1.13.254 UG 1 6 bge1
default 163.1.62.254 UG 1 3 bge0

which is what I want. However, I'd like to do this without relying on
router broadcasts, but I can't figure out how to do this. Is it even
possible?

Thanks
- Ian

--
Ian Chard, Unix & Network Administrator | E: ian.chard@sers.ox.ac.uk
Systems and Electronic Resources Service | T: 80587 / (01865) 280587
Oxford University Library Services | F: (01865) 204937

#2 (**permalink**) 01-16-2008, 08:35 AM

Ian Chard wrote:
>
> Hi,
>
> I have a V240 connected to two different subnets, and I want to be able
> to specify a different default route for each interface. If I don't
> have a /etc/defaultrouter I end up with
>
> default 163.1.13.254 UG 1 6 bge1
> default 163.1.62.254 UG 1 3 bge0
>
> which is what I want. However, I'd like to do this without relying on
> router broadcasts, but I can't figure out how to do this. Is it even
> possible?
>
> Thanks
> - Ian
>
> --
> Ian Chard, Unix & Network Administrator | E: ian.chard@sers.ox.ac.uk
> Systems and Electronic Resources Service | T: 80587 / (01865) 280587
> Oxford University Library Services | F: (01865) 204937

Touch /etc/notrouter and terminate in.routed. The file's existence will
prevent in.routed from starting.

#3 (**permalink**) 01-16-2008, 08:36 AM

Ben <ben@en-ninguna-parte.com> writes:

> Ian Chard wrote:
>> Hi,
>>
>> I have a V240 connected to two different subnets, and I want to
>> be able to specify a different default route for each
>> interface. If I don't have a /etc/defaultrouter I end up with
>>
>> default 163.1.13.254 UG 1 6 bge1
>> default 163.1.62.254 UG 1 3 bge0
>>
>> which is what I want. However, I'd like to do this without
>> relying on router broadcasts, but I can't figure out how to do
>> this. Is it even possible?
>
> Touch /etc/notrouter and terminate in.routed. The file's
> existence will prevent in.routed from starting.

Note that this will also (and primarily) disable IP forwarding in the
kernel by forcing the ip_forwarding parameter to 0; it is normally set
to 1 if more than one interface (excluding loopback) is configured for
IPv4 (see /etc/init.d/inetinit on Solaris <= 9).

So this will have an additional (and rather drastic) side effect on
the system's IP configuration (which may either break or fix the
setup, depending on what the system is supposed to do in the first
place

--
Stefan Jankowski
Sysadmin, University of Freiburg, CS Dpt.
s/spambucket//
s/dave\.null/${FORENAME}.${LASTNAME}/

#4 (**permalink**) 01-16-2008, 08:36 AM

Ben wrote:
> Ian Chard wrote:
>
>>Hi,
>>
>>I have a V240 connected to two different subnets, and I want to be able
>>to specify a different default route for each interface. If I don't
>>have a /etc/defaultrouter I end up with
>>
>>default 163.1.13.254 UG 1 6 bge1
>>default 163.1.62.254 UG 1 3 bge0
>>
>>which is what I want. However, I'd like to do this without relying on
>>router broadcasts, but I can't figure out how to do this. Is it even
>>possible?
>
> Touch /etc/notrouter and terminate in.routed. The file's existence will
> prevent in.routed from starting.

My fault for being vague :-)

If I don't run in.routed, I can't replicate the above configuration:
if I add both default routers, they aren't tied to interfaces (i.e. the
sixth column is empty), and all packets used the first default route
in the table.

- Ian

--
Ian Chard, Unix & Network Administrator | E: ian.chard@sers.ox.ac.uk
Systems and Electronic Resources Service | T: 80587 / (01865) 280587
Oxford University Library Services | F: (01865) 204937

#5 (**permalink**) 01-16-2008, 08:36 AM

Ian Chard <ian.chard@sers.ox.ac.uk> writes:
> My fault for being vague :-)
>
> If I don't run in.routed, I can't replicate the above configuration:
> if I add both default routers, they aren't tied to interfaces (i.e. the
> sixth column is empty), and all packets used the first default route
> in the table.

You'll need to write your own start-up script that does 'route add'
with the '-ifp' option to accomplish that.

(A future release will have a static route configuration feature, but
no current release does.)

(As an aside, if it works fine with regular routing, why would you
want to hard-code it into a configuration file? Doing so just means
that this machine, and all others like it, will need to be modified
the next time the network topology changes. That seems like an
operational problem to me ...)

--
James Carlson, KISS Network <james.d.carlson@sun.com>
Sun Microsystems / 1 Network Drive 71.234W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.497N Fax +1 781 442 1677

#6 (**permalink**) 01-16-2008, 08:36 AM

In article <xoavy8alew49.fsf@sun.com>,
James Carlson <james.d.carlson@sun.com> wrote:
>(As an aside, if it works fine with regular routing, why would you
>want to hard-code it into a configuration file? Doing so just means
>that this machine, and all others like it, will need to be modified
>the next time the network topology changes. That seems like an
>operational problem to me ...)

Our network topology rarely changes and when it does there is almost
always prior notice and an expectation of at least some service
interuption.

For simple, relatively static networks I see having to edit a config
file preferable and more secure than a constantly running root priv'ed
daemon that listens to the network for routing info.
--
Jim Prescott - Computing and Networking Group jgp@seas.rochester.edu
School of Engineering and Applied Sciences, University of Rochester, NY

#7 (**permalink**) 01-16-2008, 08:36 AM

jgp@harn.ceas.rochester.edu (Jim Prescott) writes:
> Our network topology rarely changes and when it does there is almost
> always prior notice and an expectation of at least some service
> interuption.
>
> For simple, relatively static networks I see having to edit a config
> file preferable and more secure than a constantly running root priv'ed
> daemon that listens to the network for routing info.

You can enable authentication if security is an issue there. Does
that mean you don't run name services such as DNS, because those can
be spoofed? What about ARP?

Or is it just the concern that in.routed runs as root and receives
packets -- and thus we had to be very careful in design and testing to
make sure it can't be compromised? If that's the issue, then it could
be run on S10 with limited privileges, but I suppose I see your point.

--
James Carlson, KISS Network <james.d.carlson@sun.com>
Sun Microsystems / 1 Network Drive 71.234W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.497N Fax +1 781 442 1677

#8 (**permalink**) 01-16-2008, 08:37 AM

James Carlson wrote:
>>If I don't run in.routed, I can't replicate the above configuration:
>>if I add both default routers, they aren't tied to interfaces (i.e. the
>>sixth column is empty), and all packets used the first default route
>>in the table.
>
>
> You'll need to write your own start-up script that does 'route add'
> with the '-ifp' option to accomplish that.

Excellent -- many thanks, that's exactly what I was looking for.

> (As an aside, if it works fine with regular routing, why would you
> want to hard-code it into a configuration file? Doing so just means
> that this machine, and all others like it, will need to be modified
> the next time the network topology changes. That seems like an
> operational problem to me ...)

Covered elsewhere in the thread I think. I personally hate using
router broadcasts, as they tend to cause odd problems (just last week
I had a machine drop off the network because of a change on a bridging
firewall that had the side effect of blocking said broadcasts).

- Ian

--
Ian Chard, Unix & Network Administrator | E: ian.chard@sers.ox.ac.uk
Systems and Electronic Resources Service | T: 80587 / (01865) 280587
Oxford University Library Services | F: (01865) 204937

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Specific default routes for each interface