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List:       zebra
Subject:    [zebra 3608] Incorrect routing table in zebra, Summary LSAs?, NO State change.
From:       Sira Panduranga Rao <pandu () euler ! ece ! iisc ! ernet ! in>
Date:       2000-04-30 9:59:35
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Hi,

 I was using 0.84c and upgraded to 0.86
following are the prob. in the scenario listed below:

            |----------|
            |          |
            |    Rc    |
            |          |  
            |__________|
                 |
                 | 144.16.94.232/19
                 |       eth0
 ________________|_______________________________
        |                                    |
        |      eth0                          |     eth0
        |144.16.94.227/19                    |144.16.94.226/19
  |----------|                          |---------|
  |          |                          |         |
  |   Rp     |                   sl0    |   Rs    |
  |          |          192.168.2.226/32|         |
  |          |__________________________|         |
  |          |192.168.2.227/32          |         |
  |__________|      sl0                 |_________|


    eth0 are in area0 
    
    sl0  are in area1


 When I look into zebra routing table at Rc the foll. is shown:

for 0.86 ver.
-------------

Router> show ip route

Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF,
        B - BGP, * - FIB route.

K* 0.0.0.0/0                   eth0 (2) 144.16.64.1
C* 1.1.1.0/24                chdlc0 (4) direct
C* 127.0.0.0/8                   lo (1) direct
C* 144.16.64.0/19              eth0 (2) direct
O* 192.168.2.226/32            eth0 (2) 144.16.94.226
O* 192.168.2.227/32            eth0 (2) 144.16.94.226    (NOTE)
Router> 


for 0.84c ver.
--------------

Router> show ip route

Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF,
        B - BGP, * - FIB route.

K* 0.0.0.0/0                   eth0 (2) 144.16.64.1
C* 1.1.1.0/24                chdlc0 (4) direct
C* 127.0.0.0/8                   lo (1) direct
C* 144.16.64.0/19              eth0 (2) direct
O* 192.168.2.226/32            eth0 (2) 144.16.94.226
O* 192.168.2.227/32            eth0 (2) 144.16.94.227     (NOTE)
Router>  


***** (NOTE): the difference is in the route to 192.168.2.227/32  ******

The same can be seen for the route 192.168.2.226/32 ...this basically
depends on who is DR. If Rs is DR then the above routing table is seen.
If Rp is DR then Rc routes to 192.168.2.226 thru Rp. 

Thus 2 hops are reqd. to reach Rp's serial interface when Rs is DR
and similarly 2 hops are reqd. to reach Rs's serial interface when Rp is
DR.

If Rc is DR then the situation is similar. 

Probable cause is the Summary LSA generation and removal. 

SEE BELOW: 

This is a PART of Link State Database in Area 0 

                 Summary Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       CkSum  Route
192.168.2.226   192.168.2.227    166 0x80000001 0x1e8d 192.168.2.226/32
192.168.2.227   192.168.2.227    186 0x80000001 0xaf05 192.168.2.227/32
          

Note that both LSAs have same ADV Router. 

In (0.84c ver. there were 4 LSAs - 2 more generated by the Rs router i.e. 
ADV Router : 192.168.3.226)

---------



1 MORE PROB. (ver. 0.86)
************

  If I start Rc 1st then after sometime start Rp and Rs (STRICTLY in that
SEQUENCE ) then these 2 routers (Rp and Rs) are NOT in FULL state with
respect to each other.

(when i say "show ip ospf neighbor"  they are in 2-Way and ExStart states)

  AT Rp :
  ------

ospfd> show ip ospf neighbor 

Neighbor ID     Pri   State           Dead Time   Address     Interface
RXmtL RqstL DBsmL

192.168.3.226     1   2-Way/Backup    00:00:39    144.16.94.226   eth0
0     0     0

144.16.94.232     1   Full/DR         00:00:35    144.16.94.232   eth0
0     0     0

192.168.3.226     1   Full/DROther    00:00:39    192.168.2.226   sl0
0     0     0
ospfd> 


   AT Rs :
   -------

ospfd> show ip ospf neighbor 

Neighbor ID     Pri   State           Dead Time   Address      Interface
RXmtL RqstL DBsmL

192.168.2.227     1   ExStart/DROther 00:00:35    144.16.94.227   eth0
0     0     0

144.16.94.232     1   Full/DR         00:00:33    144.16.94.232   eth0
0     0     0

192.168.2.227     1   Full/DROther    00:00:35    192.168.2.227   sl0
0     0     0
ospfd> 


If now I stop Rp and start again then are now in Full state w.r.t each
other. 

NOTE: This doesn't happen if I restart Rs.


Toshiaki, can you check this?
Thanks

Bye,

Regards
Panduranga

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