🚀 go-pugleaf

In article <1993Jan21.160333.901@icl.se> mniku@icl.se (Markku Niku ICL/Swe) writes:
>Hello you all knowlegdable networkers.
>We need to set up a simple routed network. We've asked our Cisco gugrus
>of this configuration, and the answers are just now : 4 = it works, 4 = it
>doesn't.
>Could somebody with experience of this give me a hint.

  Here's how you can do it.  Unfortunately you will have to renumber the hosts
  on your class C.  Since you want 20-30 hosts, use a 3 bit subnet mask, giving
  6 subnets of 30 hosts each, mask 255.255.255.224.  You lose the all zeros and
  all ones subnet, which is why you get six and not eight subnets and why
  Tony Li said you cant use a single bit subnet mask.

>We've got a class B (non standard) subnet 147.14.90.0 with 7bit host addr
>and a class C addr 192.121.128.0 (8bit hostaddr today). These are connected
>together with two IGS routers. Now we need to get a subnet to another city.
>As we are not in need to have more than about 20-30 nodes in the C net, we'd
>like to split it to 7bit host addresses and use for routing to more IGS
>routers. The way we like to connect it is as followed:
>
>
>network 192.121.128.64  <--- ug, renumbering time
>netmask 255.255.255.224       (existing)
>|-----------------------------------------------------------------------|
>	|
>	|
>   |-----------|
>   |  IGS      |
>   |-----------|	
>        Z        <-------- leased 64k line         
>   |-----------|
>   |  IGS      |
>   |-----------|
>        |                                         network 147.14.90.0
>        |                     (existing)          netmask 255.255.255.0
>|-----------------------------------------------------------------------|
>                       |                secondary network 192.121.128.192
>                       |                          netmask 255.255.255.224
>                 |-----------|
>                 |   IGS     |
>                 |-----------|                <---   NEW
>                       Z                               |
>                 |-----------|                         v 
>                 |   IGS     |
>                 |-----------|
>                       |                          network 192.121.128.128
>                       |                          netmask 255.255.255.224
>|-----------------------------------------------------------------------|
>
>Routing is to be static or IGRP.
>Will this work, and if it does/doesn't, why?

The revised diagram will work.  You can get away without the secondary address
if the two leased lines terminated on the same router, i.e. CGS or Cisco 4000
or larger.  You maight also consider looking at RFC1219 for hints on how to 
subnet in the future.


Joe Gervais                                 joeg@Novell.Com
Internetworking Products Division           (408) 473-8465
Novell, Inc.