GroupStudy.com GroupStudy.com - A virtual community of network engineers
 Home  BookStore  StudyNotes  Links  Archives  StudyRooms  HelpWanted  Discounts  Login
Translating Type 7 LSA into backbone [7:50230] posted 07/31/2002
[Chronological Index] [Thread Index] [Top] [Date Prev][Date Next] [Thread Prev][Thread Next]


I'm a bit confused. Cisco Press says, "Type 7 LSA's are advertised only
within a single NSSA; they are not flooded into the backbone area or any
other area by BR's, although the info that they contain can be propogated
into the backbone area by being translated into Type 5 LSAs by the ABR."

Now here is my scenario w/ 4 routers: (the art is terrible i know)
             
                   Area1   ------
-----  Area0-----| --------|Rt B |
Rt A |------|BB  |         -------
-----       -----| --------|Rt C |
                           -------

All 2500's running at least IOS 12.0(22)
Rt A and BB are connected via e0, AND Rt B and Rt C are connected via
ethernet.

So RtA and BB are in area0, with BB acting as ABR (And ASBR as he has 2
loopback interfaces advertising RIP into OSPF).

Area 1 is defined as NSSA on all 3 area1 routers.

Router B has the following config:

router ospf 200
redistribute connected metric-type 1 subnets route map pass1b
route-map pass1b
match ip address 1
access-list 1 permit 172.26.0.0 0.0.255.255

So on RtC and BB I can see the 3 networks I have defined as external
Loopbacks on Rtb as "N1" routes, and all looks well. I realize by default
that RtA shouldn't see these routes, but I want RtA to see these routes. I
have tried using the summary-address 172.16.0.0 255.255.0.0 command, but it
doesn't seem to work, and it gives me a message which seems to me like BB is
trying to propogate that BACK into the NSSA, and not area0.

Am I right in assuming that "summary-address" is sending this back into the
NSSA? Is this proper behavior? How do I get RtA to see these routes??

I have read many places, including Cisco Press above, which state that my
ABR (BB) can translate these type 7 LSAs into type 5 LSAs so that routers
such as RtA can see these routes, but for the life of me I can't figure out
how to do this.

Can anyone offer any advice, assitance? I have tried using TAG's and
distribute-lists, but I haven't had any success.

Thanks in advance,

Jason




Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=50230&t=50230
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to abuse@xxxxxxxxxxxxxx