Re: PM2e30s and routing protocols

Stuart Lynne (sl@whiskey.wimsey.com)
6 Oct 1995 21:23:41 GMT

In article <453lsj$1dm@vanbc.wimsey.com>, David F. Galas <dfg@cdc.net> wrote:
>
>We've run into a problem and haven't yet been able to come up with a
>solution yet, so I figured I would try here:
>
>We've got 20 Livingston 2e30s split up over 4 class C networks. Each
>works fine for dynamic IP addressing, but problems arise when we try to
>assign static IPs.
>
>Aparently, due to the limitations of the routing protocols that the 2e30s
>uses, the static IP must be on the same class C as the portmaster they
>are calling into.

>Is there any way we can have the static IPs work over all 20 portmasters?

We do this all the time. Works fine.

We use a separate Class C network for all assigned and dynamic addresses. I
allocate dynamic from the bottom, 30 at a time. And use up assigned from the
top and work down.

I find that keeping them separate from the ethernet Class C helps. For
example BSDI boxes seem to have a limit on the number of ARP entries. And
the portmasters don't rebroadcast them

I.e. if your assigned or dynamic address is on the same Class C as your
ethernet, the portmaster not only RIP's it, but also ARP's it, but it either
does not resend it periodically or on request, not sure which. Bottom line is
eventually the BSDI box stops being able to route to the oldest of the
connections on the Portmaster.

By having the connections on a separate Class C all of your other hosts and
routers simply rely on RIP to get things to where they belong and things
sort themselves out quite nicely.

-- 
Stuart Lynne <sl@wimsey.com>      604-933-1000      <http://www.wimsey.com>
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