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Conference irocz::common_brouters

Title:	Digital Brouters Conference
Notice:	New common-code brouter family: RouteAbout, DECswitch 900
Moderator:	MARVIN::HARTLL

Created:	Mon Jul 17 1995
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	929
Total number of notes:	3736

834.0. "How many DECnet/OSI Areas do Routeabout support?" by OSLLAV::BJORN () Fri Apr 04 1997 14:03

T.R	Title	User	Personal Name	Date	Lines
834.1		IROCZ::GUNNER		`Fri Apr 04 1997 17:33`	30
	>How many DECnet/OSI Areas do the Routeabout support? How many areas can it >be member of at the same time? And how many L1 routers is it wise to have in >each area? The maximum number of Area addresses that it will handle is 50. A RouteAbout can only be a member of one Area, but that area can have three area addresses. I don't know what the max no. of L1 routers is - do you have a specific number in mind ? >Another question I have is just a sanity check; Is it possible to run >Integrated IS-IS and IS-IS at the same time? There is a need to exchange >IS-IS routing information with 3rd party routers supporting only IS-IS, and >at the same time, it is a need to exhcange IP routing information with othe >Routers, supporting Integrated IS-IS, OSPF, RIP etc. I guess we do have to >maintain 2 routing tables, one for OSI and one for IP, right? No, you can't run more than one instance of IS-IS on a single router. You have to choose whether that one instance is Integrated IS-IS or just OSI-only IS-IS. However, it is possible to run Integrated IS-IS and interwork with routers running OSI-only IS-IS. This only makes sense if you never try and compute a route for IP traffic through an OSI-only router (which will drop the IP packets you send it). If you are very careful in putting together the physical topology of the routers you can make this work. You have to ensure that there will never be an OSI-only router as an intermediate hop on the path between Integrated IS-IS routers. Of course, you would also have to ensure that the OSI-only routers really implement the standards correclty and ignore any information in routing messages that they do not understand (i.e. the IP information coming from the Integrated IS-IS routers).
834.2	Is there a limit of L1 routers within one area?	OSLLAV::BJORN		`Tue Apr 08 1997 11:57`	13
834.3		IROCZ::GUNNER		`Tue Apr 08 1997 14:19`	11
	>If there are no maximum og L1 routers within one area, that is fine. >Otherwise, I need to know the limitation. BUT, most of all I would like >to have an optimal design of a network that consists of around 100 routers >with redundant links, partial mesh. I woudl expect 100 L1 routers to work but since I've never tried this I'm reluctant to claim it does work. I hope one of the engineers in REO can enter a reply about this since they have done some testing with simulated router topologies. Chris
834.4	100 should be OK	MARVIN::TURNER	Neil Turner IPEG REO, 830-4140	`Thu Apr 10 1997 06:54`	10
	I tested the Routeabout some time ago with a simulated network consisting of more than 200 L1 routers (I can't remember the exact number) with no problems. So as Chris says 100 should not be a problem. One thing to watch out for however is that the Routeabout by default only supports 100 LSUs (Link State Updates) you will need to increase this using the OSI SET GLOBALS command. Neil
834.5		MARVIN::PATEL		`Fri Apr 11 1997 07:57`	3
	The other limitation in all this is that the router neighbors have to be reported in LAN hellos. A 1500 byte hello as enough space to report about 160 to 170 neighbors.