Cisco OSPF running Dual Processes.... 1

[leedsit]

I`ll try and explain the best I can

Site B

Router 1`s serial interface is connected to the MPLS
Router 1`s Ethernet is on a Local Lan in an OSPF AS ( lets call that B )

Router 2`s Ethernet is on the Local lan in AS B also
Router 2`s Etherne 2 is connected to a Firewall which has a VPN across the internet

Site A


Router 1`s serial interface is connected to the MPLS
Router 1`s Ethernet is on a Local Lan in an OSPF AS ( lets call that A )

Router 2`s Ethernet is on the Local lan in AS A also
Router 2`s Etherne 2 is connected to a Firewall which has a VPN across the internet

Basicaly both sites edge devices are virtualy a mirror image

The MPLS Connection is simple

Site B learns a default route from Site A redistributed between protcols.
( IE Site A - AS A into the BGP cloud and then into Site B - AS B )
Site A learns all routes from Site B redistributed between protocols
( IE Site B - AS B into the BGP Cloud and then into Site A - AS A )

The backup link is a 3Des Connection between two firewalls on the edge of the
network connected to the internet
Routers 2 at each site connect directly to each firewall, these Routers have a GRE
Tunnel between then over the VPN over the internet ( GRE To carry OSPF )

At Site B, Router 2, both the local ethetet interface and the GRE Tunnel interface
are both in Area 0 of the Local AS B

At site A, Router 2, the local ethernet interface is in AS A, but the Tunnel interface
is in AS B.

Thats the setup, here is the issue.

The network with the issue is for example 129.29.x.x / 16

129.29 lives at Site B, it is redistributed into the MPLS and site A then propergates
this via OSPF througout site A

Router 2 at site A learns about this route locally and via the GRE Backup link on its
tunnel interface

So from Router 2A`s perspective

it sees 129.29 via its tunnel, as an Intra Area route.
This route is redistributed on that router from AS B into AS A however with a metric
of 500

So all other routers in site A see the 129.29 via the BGP with a cost of 200, if that
route disapears it knows about 129.29 via the Tunnel at a cost of 500.

If you look at router 2`s routing table it states
129.29.0.0 /16 via tunnel 0

If I kill the BGP connection, everything routes to Site B via the Tunnel 0

If I bring the MPLS backup, everything routes fine via the MPLS including 129.29.x.x

However once that is done, if I look at router 2A its routing table has lost the local
intra area 129.29.x.x and its been replaced with a External 129.29.x.x type 1 address as
all other routers on site A see, even through its tunnel interface is directly connected
to AS B with a Intra area Route for it.

If I run a show ip route 129.29.0.0 on Router 1B sometimes it states ( self originated )


I cannot figure this out, sorry for the complicated explanation.

Thanks, Lee

LEEroy
MCNE6,CCNA2,CWNA, Project+, CCSA

 

[leedsit]

Hi,

Ive posted a small Topology to help,

LEEroy
MCNE6,CCNA2,CWNA, Project+, CCSA

 

[KiscoKid]

I could easily be misunderstanding your setup here but it sounds like a bug to me.

Your OSPF IA route should always ALWAYS take precedence over an E1 route regardless of metric.

When this happens, how do you restore service such that the route to the remote network is via the tunnel again?

What version of IOS resides on router 2A? Do you re-establisn an OPSF neighbor with router 2B when MPLS is restored?

 

[leedsit]

Hi KiscoKid,

The neighbour ships on Router A2 are fine, these are contant ( in AS1 via the ethernet and AS2 via the tunnel ).

The only way to restore the correct routing table on A2 is to reload, a Clear Ip ospf 1 process & clear ip ospf 2 process does not fix the issue.

Version

IOS (tm) 7200 Software (C7200-IS-M), Version 12.2(2)T, RELEASE SOFTWARE

Cheers, Lee

LEEroy
MCNE6,CCNA2,CWNA, Project+, CCSA

 

[KiscoKid]

That version of IOS has 2400 bugs - 860 of which are Severity 1 bugs. It has 40 bugs related just to OSPF. Some of these OSPF ones that caught my eye are below:


CSCdx49181 (OSPF IA routes not redistributed when adding new area to PE)

CSCdu80977 (suboptimal routing for externals with multiple ABRs)

CSCdt93586 (OSPF not originating summary lsa for some areas)

CSCdx49785 (Spurious access in OSPF)

CSCdj87605 (OSPF Not Generating LSA Type 4 after link flap)


If appropriate, I would certainly consider performing an IOS upgrade as some of the bugs below are quite fundamental in their nature.

 

[leedsit]

Cheers KiscoKid,

I`ll contact BeeTee to see if they can supply us with the new version of code... wish me luck.

Thanks again.

LEEroy
MCNE6,CCNA2,CWNA, Project+, CCSA

 

[KiscoKid]

BT? Oh dear. I'm from the UK myself and they'll do the work but I bet they wanna charge you unless you can show you're getting seriously degraded service.

 

[leedsit]

Laugh.... Im UK also but hate using BT for anything... they wanted £10,000 for our ospf project so decided to do it my self. All works fine apart from this last issue. We dont have Cisco access for software etc as we purchase our kit through bt, Hence having to use them for the code. Im trying to see if they will supply only...( without the charge ).

LEEroy
MCNE6,CCNA2,CWNA, Project+, CCSA