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Conference noted::decnis

Title: DEC Network Integration Server (DECNIS)
Notice:Please read note 1 to use this conference effectively
Moderator:MARVIN::WELCH
Created:Wed Sep 18 1991
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:3660
Total number of notes:15082

3593.0. "IP routing path selection" by GIDDAY::CHONG (Andrew Chong - Sydney CSC) Tue Apr 08 1997 07:36

  In the network configuration below, when the metrowave link breaks, IP
traffic from DECNIS1 takes the slower path (64K->160K->64K) to DECNIS3. 
Why is it not taking the fast path (2M->10M->2M) ?


						   ethernet Lan
	=========	=======			======================
	    |	  	    |                       |		|
	  Brouter1--/\/---Brouter2		 DECNIS2    Brouter3
            |       160k     |			    |		|
	    |		     |64k		    |2M		|2M	
	    |64k	     +---------+	    |		|	
	    |		+--------------|------------+		|
	    +-------+	|	       |  +---------------------+
		    |	|	       |  |
		    |	|	       |  |
		    |	|	       |  |
		   DECNIS3	      DECNIS1
		      |			|
		  =======----/\/----============	
		          Metrowave
			    10M

Is this because both path is 3 hops and RIP cannot determine which path is more
efficient ? What configuration changes is required to make sure that the faster
path is used (assuming RIP protocol) when the metrowave fails ?

    Andrew
    

T.RTitleUserPersonal
Name
DateLines
3593.1MARVIN::PATELWed Apr 09 1997 06:418
	>Is this because both path is 3 hops and RIP cannot determine which path is more
	>efficient ? What configuration changes is required to make sure that the faster
	>path is used (assuming RIP protocol) when the metrowave fails ?

This is correct. RIP use hop count rather than metric. To get round this problem
create a RIP control protocols for the various instances to import/export the routes
and set the announce metric appropriately to get the effect you want of using the
higher bandwidth interfaces when the metrowave link breaks.
3593.2how do I specify IP sources ?GIDDAY::CHONGAndrew Chong - Sydney CSCFri Apr 18 1997 02:2755
>This is correct. RIP use hop count rather than metric. To get round this problem
>create a RIP control protocols for the various instances to import/export the r
>and set the announce metric appropriately to get the effect you want of using t
>higher bandwidth interfaces when the metrowave link breaks.


	I tried to create 2 RIP control protocols (one for each of the redundent
path) , specified the ip subnets , preference and ip source . This is done in 
the extra file. But the compiler complains about the ip source ! The message 
in the log file is :


Enable Node CSC_NS:.CSC.x Routing Control Protocol crkRip
 at 1997-04-18-11:55:35.42050 + 00:00 I 28147497.67107

Command failed due to:
 process failure

One or more values in IP Sources does not belong to any<NEL>                   
%SYSTEM-F-ABORT, abort



This is extract from the extra file :

!
! To force issue with path over IP to Moonah when Metro wave down
! Make IP go via Creek RD (2M link) not via new norfolk(64k link) same number
! of hops
!
Create routing control proto crkRip type IP RIP
set routing control proto crkRip ip sources {192.168.242.254}
set routing control protocol crkRip rip state Send and Receive
set routing control protocol crkRip ip subnets {{addr= 172.19.0.0 -
         ,mask= 255.255.0.0 }}
set routing control protocol crkRip Preference 80
enable routing control protocol  crkRip
!
Create routing control proto nnkRip type IP RIP
set routing control proto nnkRip ip sources {192.168.237.254}
set routing control protocol nnkRip rip state Send and Receive
set routing control protocol nnkRip ip subnets {{addr= 172.19.0.0 -
         ,mask= 255.255.0.0 }}
set routing control protocol nnkRip Preference 96
enable routing control protocol  nnkRip
!
!




What did I do wrong ?

Andrew
    
3593.3MARVIN::PATELFri Apr 18 1997 08:105
The "IP Sources(s)" you specify must belong to one of the subnets you specify in
the "IP Subnets" attribute. In your script you are setting up a RIP instance
to run in subnet 172.19.0.0 but you are specifying that the source of RIP updates
that will be listened to is 192.168.237.254. This is obviously a mismatch and the
compiler then complains.
3593.4 will this work ?GIDDAY::CHONGAndrew Chong - Sydney CSCMon Apr 21 1997 06:23102
>The "IP Sources(s)" you specify must belong to one of the subnets you specify
> in the "IP Subnets" attribute. In your script you are setting up a RIP 
>instance to run in subnet 172.19.0.0 but you are specifying that the source 
>of RIP updates that will be listened to is 192.168.237.254. This is obviously
>a mismatch and the compiler then complains.

	Thanks for point this out. After reading the management manual on IP
routing, and IP route propergation and filtering, I come up with the following 
extra script. Please review it and let me know if this will achieve what I want
to do ( to force Ip traffic over the 2M link when the metrowave fails. Current
siuation is that the failover happens on the 64K link).


			CRK site		   NNK site

						   ethernet Lan
	=========	=======			======================
	    |	  	    |                       |		|
	  Brouter1--/\/---Brouter2		 DECNIS2    Brouter3
            |       160k     |192.168.242.254	    |		|192.168.237.254
	    |		     |64k		    |2M		|2M	
	    |64k	     +---------+	    |		|	
	    |	       + --------------|------------+		|
	    +-------+  |	       |   +--------------------+
		    |  |	       |   |
		    |  |	       |   |
		    |  |	       |   |
		   DECNIS3	      DECNIS1
		      |	|		| |
		      |	+-------/\/-----+ |	
		===========		============	
		172.19.0.0    Metrowave	 172.20.0.0	
			       10M


The steps taken in the script :

	- delete IP subnet (192.168.242.0) and (192.168.237.0) from routing 
	  control protocol riptxrx.
	- create RIP routing control protocol for (192.168.242.0) and 
	  (192.168.237.0) 
	- create receive destination filter specifying domain containing 
	  address 172.19.0.0 and metric for each control protocol.

Question:
	
	Given that I am creating different instances of the control protocol 
for RIP, will I need to propagate the routes (RIP - RIP ) between the differnet 
control protocol instance ?   


The extra script :

!
! delete ip subnet for the serial interfaces from RipTxRx and create 
! new rip control protocol for each.
!
delete routing control protocol RipTxRx ip subnets {{addr= 192.168.237.253 -
 ,mask= 255.255.255.0},{addr= 192.168.237.253 ,mask=255.255.255.0}}
!
Create routing control proto crkRip type IP RIP
set routing control protocol crkRip rip state Send and Receive
set routing control protocol crkRip ip subnets {{addr= 192.168.242.253 -
         ,mask= 255.255.255.0 }}
enable routing control protocol  crkRip
!
Create routing control proto nnkRip type IP RIP
set routing control protocol nnkRip rip state Send and Receive
set routing control protocol nnkRip ip subnets {{addr= 192.168.237.253 -
         ,mask= 255.255.255.0 }}
enable routing control protocol  nnkRip
!
! create domain entity for filters
!
Create routing network protocol ip domain Moonah
set routing network protocol ip domain Moonah ip address -
	{{address=172.19.0.0 ,mask=255.255.0.0}}
!
! create receive destination filters with  matric 3 and 6 
!
Create routing control proto nnkRip receive destination 2Meg 
set routing control proto nnkRip receive destination 2Meg domains -
	{{routing network protocol ip domain Moonah}} 
set routing control proto nnkRip receive destination 2Meg filter action pass
set routing control proto nnkRip receive destination 2Meg - 
	address match type prefix 
set routing control proto nnkRip receive destination 2Meg metric 3
enable routing control proto nnkRip receive destination 2Meg
!
!
Create routing control proto crkRip receive destination 64K
set routing control proto crkRip receive destination 64K domains -
        {{routing network protocol ip domain Moonah}}
set routing control proto crkRip receive destination 64K filter action pass
set routing control proto crkRip receive destination 64K -
        address match type prefix
set routing control proto crkRip receive destination 64K metric 6
enable routing control proto crkRip receive destination 64K




3593.5MARVIN::PATELMon Apr 21 1997 09:222
A quick look at the script shows that it will not work since you are using metric
and there is no metric attribute on a receive destination. Use preference instead.