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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

911.0. "Designated router among RouteAbout in Ph IV problems?" by ZUR01::DEMETRIOU () Wed May 21 1997 15:45

    Question:
    
    is it any problem with the designated router (Phase IV as the level 1
    routing algo. is setted to distance vector and L2 to link state)
    if on the same LAN are two or more Central Router with V2.0-2?
    I changed the circuit route priority on both routers and seems that
    they see both themselfs as the designated router even though a 
    DBrouter90 (CISCO) router on the same LAN (Phase IV router) sees
    that its designated router is the one with the highest router 
    priority!
    The other think I noticed is that the Central Router (doing
    conversion between IV to OSI and vice versa between end nodes 
    on an extended LAN as well as on a WAN) after a while is having
    very bad performance that the user can not really work. Any idea?
    
    
    regards
    Phyl

T.R	Title	User	Date	Lines
911.1	I'm seeing the DR problem	FOUNDR::VECCHI	`Fri May 23 1997 14:29`	9
	Hi Phyl, We received your IPMT case on this problem. I've setup a configuration in our lab and experienced the DR problem described. We will continue to work this and the performance problem as required by IPMT and update this note when problems are resolved. If anyone else out there has experienced this problem or has input, feel free to comment. thanks, rich
911.2		MARVIN::GARVEY	`Wed May 28 1997 16:37`	42
	Hi Phyl, In your initial entry, you state that :- > is it any problem with the designated router (Phase IV as the level 1 > routing algo. is setted to distance vector and L2 to link state) > if on the same LAN are two or more Central Router with V2.0-2? > I changed the circuit route priority on both routers and seems that > they see both themselfs as the designated router even though a > DBrouter90 (CISCO) router on the same LAN (Phase IV router) sees > that its designated router is the one with the highest router > priority! This is indeed a bug and I am currently working on a solution. The problem arises from the fact that a phase V router will discard all received phase IV Hello messages which specify version 2.2 (i.e. those originating from another phase V router). The priority level which is configured from within the phase IV environment is only encoded in these phase IV hellos. This then leads to the inconsistencies which your are observing. A simple work-a-round is to ensure that the configured phase IV priority level and the L1 and L2 OSI priority levels are ALL set to the same value. > The other think I noticed is that the Central Router (doing > conversion between IV to OSI and vice versa between end nodes > on an extended LAN as well as on a WAN) after a while is having > very bad performance that the user can not really work. Any idea? I am a bit confused by this one. When routing phase IV traffic over a circuit other than the one it was received on, a phase V router will always translate into phase V format if the next hop adjacency is a phase V router, irrespect of the routing algorithm being used. (DNA V spec., section 4.5.9) However on an 'extended LAN' (i.e. I assume you mean a bridged LAN) the forwarding should be done via the bridging code and not the routing code. So, I cannot see how the data could be translated. Can you help shed some light on this please? regards, Kevin.