🚀 go-pugleaf

We are in the process of becoming a "Cisco shop," planning to 
install Cisco routers in our internal internet.

We will be replacing a series of redundant single-port (ethernet
and serial) routers from Ungermann-Bass, running strictly the
UB-XNS protocol, in the following configuation:
(the redundancies in routers are put in under the requirement
of 99.99% uptime for our users; which we feel requires any
single piece of network equipment's demise to be transparent 
to the user community):
           ______         ______
      |   |router|---/---|router|   |
user  |---|______|       |______|---| 
802.3 |    ______         ______    |
LAN1  |---|router|---/---|router|---|
      |   |______|       |______|   |
 	                            | host
           ______         ______    | 802.3
      |   |router|---/---|router|   | LAN
user  |---|______|       |______|---|
802.3 |    ______         ______    |
LAN2  |---|router|---/---|router|---|
      |   |______|       |______|   |
		    56Kb
		   and/or
		 T1 circuits


We have been discussing the possibility of replacing the 
Ungermann-Bass routers with Cisco routers in the 
following configuration:
           ______         ______
      |   |router|---/---|router|    |
user  |---|______|      /|______|----| 
802.3 |    ______      /             |
LAN1  |---|router|    /              |
      |   |______|\  /               |
	           \/                | host
           ______  /\                | 802.3
      |   |router|/  \               | LAN
user  |---|______|    \              | 
802.3 |    ______      \  ______     |
LAN2  |---|router|      \|router|----|
      |   |______|---/---|______|    |

		    56Kb
		   and/or
		 T1 circuits


In this configuration, we are going to want to run the routers
initially with both TCP/IP and the UB-XNS protocol (eventually 
we will want to add Appletalk and maybe IPX).

Given we need to keep the "transparency" requirement, do we 
still need redundant routers?

Does anyone out there have experience in running this type of 
configuration?

In this configuration, would the routers do load sharing, 
"hot standby" and/or both (we can supply enough bandwidth to
allow for a single circuit from a given router to be able to 
handle all the traffic with the other as backup)?  

Would the answer to this be the same for both the IP and 
UB-XNS protocols (any long term implications for Appletalk
and/or IPX)?

Any help, assistance, opinions, would be welcome and encouraged
(we have people on both sides of the discussion internally,
so opinions from knowledgeable outside sources is most welcome).

Thanks,

Guy Tonti
Pacific Bell, Data Communications Planning

gjtonti@ns.pacbell.com
510.867.6659  (ofc)
510.275.5716  (pgr)
SRV - 3N250   (mail)
SRV - 3N000AA (ofc)