[comp.sys.sun] setting up a sun as a router

dg0951@cec1.wustl.edu (Daniel Geist) (02/24/90)

I am trying to set up my sun as a router without much success. I have an
extra Ethernet card and I can talk to both my networks. But no machine on
one side can talk to a machine on the other side. I seems like my sun does
not pass packets between sides. I have for each side two different class B
numbers i.e 128.252.123.xxx and 128.252.145.xxx. If anyone has done this
before I need your help I seem to be missing something.

neil@uunet.uu.net (Neil Gorsuch) (02/25/90)

In article <5281@brazos.Rice.edu> dg0951@cec1.wustl.edu (Daniel Geist) writes:
>I am trying to set up my sun as a router without much success. I have an
>extra Ethernet card and I can talk to both my networks. But no machine on
>one side can talk to a machine on the other side. I seems like my sun does
>not pass packets between sides. I have for each side two different class B
>numbers i.e 128.252.123.xxx and 128.252.145.xxx. If anyone has done this
>before I need your help I seem to be missing something.

Me too, except that I am using SLIP instead of a second ethernet interface.

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scp@acl.lanl.gov (Stephen C. Pope) (02/27/90)

dg0951@cec1.wustl.edu (Daniel Geist) said:

> I am trying to set up my sun as a router without much success. I have an
> extra Ethernet card and I can talk to both my networks. But no machine on
> one side can talk to a machine on the other side. I seems like my sun does
> not pass packets between sides. I have for each side two different class B
> numbers i.e 128.252.123.xxx and 128.252.145.xxx. If anyone has done this
> before I need your help I seem to be missing something.

Make sure that ip forwarding is turned on in your kernal; use adb to check
the variable ``ipforwarding''.  Also make sure that you've got the proper
default routing set up on both your hosts on either side of the host doing
the routing so that they know how to get to each other.  I've noted
problems doing this until I used the ``default'' option to route instead
of trying to specify the network explicitly.

stephen pope
advanced computing lab, lanl
scp@acl.lanl.gov

schenker@tdw220.ed.ray.com (03/02/90)

In order to use the machine as a router, you should check with netstat -r
to see if routing is taking place.  If not, you can add routing with
either an entry in /etc/gateways ( and then rebooting) or by using
/usr/etc/route.  Then check again with netstat to make sure routing is
occurring.  We currently have several routers in place and working.

Also make sure routed has been started.

dg0951@cec1.wustl.edu (Daniel Geist) (03/05/90)

Thanks to those that replied (And there were many) to summarize
the reponses:

1) Make sure your ipforwarding flag is up in your kernel. This is usually
   the default.
2) Make sure your netmask is set properly this is the root of most
   difficulties (at least mine). If you are running two class C networks
   128.252.123.XXX and 128.252.145.XXX you have to have the net masks on both
   sides (And on all computers to be 255.255.255.0.
3) Make sure everey host knows where to send packets. This can be done by
   activating in.routed or by manually specifying routes using the route
   command.

				   Thanks again
				    Danny Geist

lehners@cs.utexas.edu (Joerg Lehners) (03/08/90)

dg0951@cec1.wustl.edu (Daniel Geist) writes:
>Thanks to those that replied (And there were many) to summarize
>the reponses:
> [3 suggestions deleted]

4.) Be sure the sun is set up with a brodcast address set to all bits 1 if
    your ethernet does not contain just suns.

We had severe ARP-storms a few days ago. They were triggered by a sun with
a broadcast adress set to all bits 0 (standard sun setting).  I used
'etherfind' on some other sun (with correct broadcast setting) to analyse
the disaster: lots of ARP-backets, lots of other broadcast traffic (more
than 1000 times as much as usual [maybe broadcast resending ? Some
machines sent out 10 to 50 broadcast RIP and rwho pakets in a second.
Usually the rates are one packet in 30 seconds resp. one packet in 3
minutes]). All the problems went away a soon as I fixed the broadcast
address of the offending sun.  We have a mixed envronment: Sun3, Sun4,
Apollo Domain, PCS Cadmus, IBM-AT, MacIntosh and a VM/XA system.  The
'storms' does not show up here when we used class C networks without
subnets. It just started since we use a registered subnetted class B
network. All Suns run SunOS 4.0.3. The other machines use the BSD 4.3
TCP/IP code and other stuff.

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