From: Carlos (cchorao@xtra.co.nz)
Date: Fri Feb 21 2003 - 07:18:39 GMT-3
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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