From: soon ccie (soonccie@yahoo.com)
Date: Sun Feb 23 2003 - 09:10:19 GMT-3
Example: If you do not enable "no-redistribution" option, e.g. if you
redistribute connected of a loopback int at R5, it enter R5 datase as
type 5 and will enter R6 as NSSA type 7.
It is alos in http://www.cisco.com/warp/customer/104/nssa.html
"There are situations where there is no need to inject external routes
into the NSSA as type 7. This situation usually occurs when an ASBR is
also an NSSA ABR. When redistribution takes place in this scenario, the
router generates type 5 as well as type 7 LSAs. You can prevent the
router from creating type 7 LSAs for NSSA using the following command:
router ospf 1
area 1 nssa no-redistribution"
HTH
--- Carlos <cchorao@xtra.co.nz> wrote:
> The ABR to a nssa will not allow type 5's into the nssa and wont
> convert
> type 5 into type 7's
> Have a look at this link
> http://www.cisco.com/warp/customer/104/nssa.html
>
> look at the comments in the para below the diagram
>
> Also look at
>
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/ip_c
> /ipcprt2/1cdospf.htm#1001252
>
> Could you perhaps supply a scenrario that demontrates lsa 5 to 7
> conversion.
>
> Tx
>
>
>
> Carlos
> Telecom New Zealand - Advanced Solutions Group : Network Design and
> Security
> ----- Original Message -----
> From: "soon ccie" <soonccie@yahoo.com>
> To: "Carlos" <cchorao@xtra.co.nz>; "Hunt Lee"
> <huntl@webcentral.com.au>
> Cc: <ccielab@groupstudy.com>
> Sent: Friday, February 21, 2003 10:44 PM
> Subject: Re: IBGP redistribution mystery
>
>
> >
> > NSSA ABR should convert type 5 to 7, it should enter as NSSA route.
> >
> > "sh ip ospf data ex 200.200.200.0" to check the "forward-address",
> > which must be an OSPF inter/intra area route before you can advance
> > 200.200.200.0 from ospf database to routing table.
> >
> >
> > --- Carlos <cchorao@xtra.co.nz> wrote:
> > > Hunt ,
> > >
> > > Based on my experiences so far the answer to your question would
> be
> > > no. The
> > > abr(r5)
> > > does type 7 to 5 translation , not 5 to 7 i.e external routes
> > > originating
> > > on R6 will reach R5 and R5 will pass these into the backbone,
> however
> > > type
> > > 5's arriving at R5 through the backbone are never into the nssa
> area
> > > and so
> > > r6 should never see these routes.
> > >
> > >
> > >
> > >
> > >
> > > Carlos
> > > Telecom New Zealand - Advanced Solutions Group : Network Design
> and
> > > Security
> > > ----- Original Message -----
> > > From: "Hunt Lee" <huntl@webcentral.com.au>
> > > To: "'Carlos'" <cchorao@xtra.co.nz>
> > > Cc: <ccielab@groupstudy.com>
> > > Sent: Friday, February 21, 2003 5:59 PM
> > > Subject: RE: IBGP redistribution mystery
> > >
> > >
> > > > Hi Carlo,
> > > >
> > > > That's exactly my point... if I redistribute BGP into OSPF at
> R5,
> > > shouldn't
> > > > the BGP route get into the OSPF as LSA Type 7??
> > > >
> > > > Hunt
> > > >
> > > >
> > > > -----Original Message-----
> > > > From: Carlos [mailto:cchorao@xtra.co.nz]
> > > > Sent: Friday, 21 February 2003 1:05 PM
> > > > To: Hunt Lee
> > > > Cc: ccielab@groupstudy.com
> > > > Subject: Re: IBGP redistribution mystery
> > > >
> > > >
> > > > Hunt,
> > > >
> > > > The purpose of NSSA is to enable the area to have stub
> > > capablities ( i.e
> > > > no lsa 5's in the area) but still allowing into originate
> external
> > > routes
> > > > (as type 7 lsa's). A default route must be injected at the abr
> if
> > > the
> > > > routers inside the nssa need to reach type 5 lsa's
> destinations.
> > > >
> > > >
> > > > Tx
> > > > Carlos
> > > > Telecom New Zealand - Advanced Solutions Group : Network Design
> and
> > > Security
> > > > ----- Original Message -----
> > > > From: "Hunt Lee" <huntl@webcentral.com.au>
> > > > To: "'Carlos'" <cchorao@xtra.co.nz>
> > > > Cc: <ccielab@groupstudy.com>
> > > > Sent: Friday, February 21, 2003 3:28 PM
> > > > Subject: RE: IBGP redistribution mystery
> > > >
> > > >
> > > > > Correctly me if I'm wrong, but I thought the whole point of
> NSSA
> > > is to
> > > > allow
> > > > > "external routes" to get in while having Stub area capability
> at
> > > the
> > > same
> > > > > time???
> > > > >
> > > > > Or am I completely off??
> > > > >
> > > > > Best Regards,
> > > > > Hunt Lee
> > > > >
> > > > >
> > > > > -----Original Message-----
> > > > > From: Carlos [mailto:cchorao@xtra.co.nz]
> > > > > Sent: Friday, 21 February 2003 10:02 AM
> > > > > To: Hunt Lee; ccielab@groupstudy.com
> > > > > Subject: Re: IBGP redistribution mystery
> > > > >
> > > > >
> > > > > Hunt,
> > > > >
> > > > > if r5-r6 is a nssa , then no type 5 lsa enter the area. Net
> > > 200.200.200.0
> > > > is
> > > > > a type 5. Why should it appear on R6 ?
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Carlos
> > > > > Telecom New Zealand - Advanced Solutions Group : Network
> Design
> > > and
> > > > Security
> > > > > ----- Original Message -----
> > > > > From: "Hunt Lee" <ciscoforme3@yahoo.com.au>
> > > > > To: <ccielab@groupstudy.com>
> > > > > Sent: Thursday, February 20, 2003 2:35 AM
> > > > > Subject: IBGP redistribution mystery
> > > > >
> > > > >
> > > > > > Hi Group,
> > > > > >
> > > > > > Just got a funny stuff. Remember how they said that with
> "bgp
> > > > > > redistribute-internal", one can then redistribute IBGP
> routes
> > > into IGP
> > > > > (like OSPF).
> > > > > > Well... I just got a wierd one, perhaps some of you can
> try.
> > > Here is
> > > > the
> > > > > topology
> > > > > >
> > > > > > r4---EBGP---r3---OSPF Frame---r1---OSPF
> Frame---r5---NSSA---r6
> > > > > >
> > > > > > So now, what I did, I put a "redistribute bgp 3" at r5
> under
> > > OSPF
> > > > process,
> > > > > but the
> > > > > > IBGP route just doesn't want to get into the NSSA area.
> > > > > >
> > > > > > router ospf 1
> > > > > > log-adjacency-changes
> > > > > > area 4 authentication
> > > > > > area 4 nssa default-information-originate
> > > > > > area 4 default-cost 20
> > > > > > redistribute bgp 3 metric 20 subnets
> > > > > > network 10.10.1.5 0.0.0.0 area 0
> > > > > > network 11.1.1.5 0.0.0.0 area 4
> > > > > >
> > > > > > router bgp 3
> > > > > > no synchronization
> > > > > > bgp redistribute-internal
> > > > > > bgp log-neighbor-changes
> > > > > > neighbor 10.10.1.1 remote-as 3
> > > > > >
> > > > > >
> > > > > > Here is the routing table of r5
> > > > > >
> > > > > > B 200.200.200.0/24 [200/0] via 10.10.1.3, 03:33:03
> > > > > > 137.20.0.0/24 is subnetted, 1 subnets
> > > > > > O IA 137.20.20.0 [110/138] via 10.10.1.1, 00:00:25,
> Serial0
> > > > > > 22.0.0.0/24 is subnetted, 1 subnets
> > > > > > B 22.1.1.0 [200/0] via 10.20.1.1, 00:51:42
> > > > > > 10.0.0.0/8 is variably subnetted, 11 subnets, 4 masks
> > > > > > O 10.10.1.1/32 [110/64] via 10.10.1.1, 00:00:26,
> Serial0
> > > > > > C 10.10.0.0/16 is directly connected, Serial0
> > > > > > O 10.10.1.3/32 [110/128] via 10.10.1.1, 00:00:26,
> Serial0
> > > > > > O IA 10.3.1.1/32 [110/129] via 10.10.1.1, 00:00:27,
> Serial0
> > > > > > O IA 10.1.0.0/17 [110/65] via 10.10.1.1, 00:00:27,
> Serial0
> > > > > > O IA 10.4.0.0/16 [110/202] via 10.10.1.1, 00:00:27,
> Serial0
> > > > > > O IA 10.20.0.0/16 [110/128] via 10.10.1.1, 00:00:27,
> Serial0
> > > > > > O IA 10.44.1.1/32 [110/193] via 10.10.1.1, 00:00:28,
> Serial0
> > > > > > B 10.44.0.0/16 [200/0] via 10.10.1.3, 03:33:05
> > > > > > O IA 10.34.0.0/16 [110/192] via 10.10.1.1, 00:00:28,
> Serial0
> > > > > > O IA 10.33.1.0/25 [110/129] via 10.10.1.1, 00:00:28,
> Serial0
> > > > > > 11.0.0.0/16 is subnetted, 4 subnets
> > > > > > O N1 11.3.0.0 [110/21] via 11.1.1.6, 00:00:28, Ethernet0
> > > > > > O N1 11.2.0.0 [110/21] via 11.1.1.6, 00:00:28, Ethernet0
> > > > > > C 11.1.0.0 is directly connected, Ethernet0
> > > > > > O N1 11.4.0.0 [110/21] via 11.1.1.6, 00:00:28, Ethernet0
> > > > > > 30.0.0.0/24 is subnetted, 1 subnets
> > > > > > B 30.1.2.0 [200/0] via 10.10.1.3, 03:33:05
> > > > > > O*E2 0.0.0.0/0 [110/1] via 10.10.1.1, 00:00:28, Serial0
> > > > > > R5#
> > > > > >
> > > > > > ANd here is the OSPF database
> > > > > >
> > > > > > Type-7 AS External Link
> States
> > > (Area 4)
> > > > > >
> > > > > > Link ID ADV Router Age Seq#
> Checksum
> > > Tag
> > > > > > 0.0.0.0 11.1.1.5 1167 0x80000008
> 0x66D
> > > 0
> > > > > > 10.44.0.0 11.1.1.5 670 0x80000002
> 0x336
> > > 2
> > > > > > 11.2.0.0 11.2.1.1 910 0x80000006
> 0x845E
> > > 0
> > > > > > 11.3.0.0 11.2.1.1 910 0x80000006
> 0x7869
> > > 0
> > > > > > 11.4.0.0 11.2.1.1 910 0x80000006
> 0x6C74
> > > 0
> > > > > > 22.1.1.0 11.1.1.5 671 0x80000002
> 0xDB85
> > > 0
> > > > > > 30.1.2.0 11.1.1.5 671 0x80000002
> 0xED60
> > > 2
> > > > > > 200.200.200.0 11.1.1.5 671 0x80000002
> 0x5BB9
> > > 2
> > > > > >
> > > > > > Type-5 AS External Link States
> > > > > >
> > > > > > Link ID ADV Router Age Seq#
> Checksum
> > > Tag
> > > > > > 0.0.0.0 10.20.1.1 1052 0x80000007
> 0x2765
> > > 1
> > > > > > 10.44.0.0 11.1.1.5 672 0x80000002
> 0xE470
> > > 2
> > > > > > 11.2.0.0 11.1.1.5 50 0x80000001
> 0x13DB
> > > 0
> > > > > > 11.3.0.0 11.1.1.5 50 0x80000001
> 0x7E6
> > > 0
> > > > > > 11.4.0.0 11.1.1.5 50 0x80000001
> 0xFAF1
> > > 0
> > > > > > 22.1.1.0 11.1.1.5 672 0x80000002
> 0x1F56
> > > 0
> > > > > > 30.1.2.0 11.1.1.5 672 0x80000002
> 0xCF9A
> > > 2
> > > > > > 200.200.200.0 11.1.1.5 672 0x80000002
> 0x3DF3
> > > 2
> > > > > > R5#
> > > > > >
> > > > > > And for r6's OSPF database:
> > > > > >
> > > > > >
> > > > > > Type-7 AS External Link States (Area 4)
> > > > > >
> > > > > > Link ID ADV Router Age Seq#
> Checksum
> > > Tag
> > > > > > 0.0.0.0 11.1.1.5 1204 0x80000008
> 0x00066D
> > > 0
> > > > > > 10.44.0.0 11.1.1.5 708 0x80000002
> 0x000336
> > > 2
> > > > > > 11.2.0.0 11.2.1.1 946 0x80000006
> 0x00845E
> > > 0
> > > > > > 11.3.0.0 11.2.1.1 946 0x80000006
> 0x007869
> > > 0
> > > > > > 11.4.0.0 11.2.1.1 946 0x80000006
> 0x006C74
> > > 0
> > > > > > 22.1.1.0 11.1.1.5 708 0x80000002
> 0x00DB85
> > > 0
> > > > > > 30.1.2.0 11.1.1.5 708 0x80000002
> 0x00ED60
> > > 2
> > > > > > 200.200.200.0 11.1.1.5 708 0x80000002
> 0x005BB9
> > > 2
> > > > > > R6#
> > > > > >
> > > > > > But nothing shows up in routing table of r6
> > > > > >
> > > > > > R6#sh ip route 200.200.200.0
> > > > > > % Network not in table
> > > > > > R6#
> > > > > >
> > > > > >
> > > > > > Any help / ideas would be greatly appreciated.
> > > > > >
> > > > > > Regards,
> > > > > > Hunt
> > > > > >
> > > > > > http://mobile.yahoo.com.au - Yahoo! Mobile
> > > > > > - Exchange IMs with Messenger friends on your Telstra or
> > > Vodafone
> > > mobile
> > > > > phone.
> >
> >
> > __________________________________________________
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>
>
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