RE: equal cost path

From: Victor Cappuccio (victor@ccbootcamp.com)
Date: Fri May 25 2007 - 13:37:11 ART


 You can usually use the show ip route command to find equal cost routes. For
example, below is the show ip route command output to a particular subnet that
has multiple routes. Notice there are two routing descriptor blocks. Each
block is one route. There is also an asterisk (*) next to one of the block
entries. This corresponds to the active route that is used for new traffic.
The term 'new traffic' corresponds to a single packet or an entire flow to a
destination, depending on the type of switching configured.

      For process-switchingload balancing is on a per-packet basis and the
asterisk (*) points to the interface over which the next packet is sent.

      For fast-switchingload balancing is on a per-destination basis and the
asterisk (*) points to the interface over which the next destination-based
flow is sent.

The position of the asterisk (*) keeps rotating among the equal cost paths
each time a packet/flow is served.

    M2515-B# show ip route 1.0.0.0
    Routing entry for 1.0.0.0/8
      Known via "rip", distance 120, metric 1
      Redistributing via rip
      Advertised by rip (self originated)
      Last update from 192.168.75.7 on Serial1, 00:00:00 ago
      Routing Descriptor Blocks:
      * 192.168.57.7, from 192.168.57.7, 00:00:18 ago, via Serial0
          Route metric is 1, traffic share count is 1
        192.168.75.7, from 192.168.75.7, 00:00:00 ago, via Serial1
          Route metric is 1, traffic share count is 1

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094820.
shtml

thanks,
Victor Cappuccio.-
- CCSI# 31452
Network Learning Inc - A Cisco Sponsored Organization (SO) YES! We take
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victor@ccbootcamp.com
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-----Original Message-----
From: nobody@groupstudy.com on behalf of Ovidiu Neghina
Sent: Fri 5/25/2007 9:27
To: Cisco certification
Subject: equal cost path

Hi dear all
do you know what * indicates in show ip route a.b.c.d ?

R4#sh ip route 10.1.37.7
Routing entry for 10.1.37.0/24
  Known via "ospf 1", distance 110, metric 130, type intra area
  Last update from 150.1.24.2 on FastEthernet0/0, 00:00:44 ago
  Routing Descriptor Blocks:
  * 150.1.45.5, from 150.1.3.3, 00:00:44 ago, via Serial0/1/0.1
      Route metric is 130, traffic share count is 1
    150.1.24.2, from 150.1.3.3, 00:00:44 ago, via FastEthernet0/0
      Route metric is 130, traffic share count is 1

10x
Ovidiu



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