From: hedrick@athos.rutgers.edu (Charles Hedrick) Subject: Re: Problems with KA9Q and SLIP Date: 26 Sep 1992 01:52:34 GMT
prv2d@fulton.seas.Virginia.EDU (Peter Villadsen) writes:
> We recently have installed a number of high-speed dialin
>modems that run off a cisco server that supports SLIP. I
>am attempting to use ka9q to establish a SLIP connect thru
>my UNIX box at home. Here are the details:
> My setup is as follows: 386/25 8 megs of RAM
> 65meg Linux Partition
> Supra V32bis running on serial
> line #2
You have two symptoms:
- connections open but then hang
- you can't get to certain destinations.
1) I suspect that you have incompatible settings for compression or
MTU. Unless you are running the very latest Cisco software (which is
still in beta), you probably don't have support for compressed Slip.
Please check the "attach" command. It should say
attach asy 0 /dev/... slip sl0 2048 1500 <speed>
I use cslip instead of slip. That will cause the symptoms you observe
if your terminal server doesn't support compression. The connection
will start, and then hang. Note also that many SLIP implementations
default to an MTU of 1006. That could conceivably cause trouble if
you set an MTU of 1500, as in the above example. Probably it wouldn't
actually have any effect though, since I recommend using a command
like "tcp mss 64" (though if you don't do header compression you'll
want a somewhat larger number than 64). If you have an mss smaller
than the MTU, then the MTU doesn't really do much.
2) As for not being able to ping systems that are farther away, this
sounds like a routing problem. Make sure you have a default route,
e.g. "route add default sl0". It's also possible that your campus net
is set up intentionally to prevent access to external destinations.
Internet policy requires authentication for anyone attached to the
Internet. If your terminal server doesn't require a login, your staff
may reasonably believe that they shouldn't allow access to
destinations outside your site.
Finally, you seem to be using an address of the form a.b.c.d. KA9Q
wants numeric addresses to be specified as [a.b.c.d]. Without the
brackets it will treat the address as symbolic, and try to look it up
as a name.