Re: Protected ports blocking ospf hello, but Virtual Link still

A few things to check...

1. I see you have authentication, if area 0 has authentication then area 10 needs it also.

2. Check your timers to make sure they match.

3. If R6 is indeed not connected to area 0, thats what it looks like from your awesome diagram then it will need a VL plus authentication ( If area 0 has authentication)

4. Since there all connected to the same switch you should be fine as the TTL is set to one, if not then you would need a "Hub and Spoke" type setup.

On May 24, 2010, at 10:11 AM, Ladee Geek wrote:

> (area 0) ---- R1*---------*(area 10)--------R4----(area 104)
> |
> R6
>
> Hi All -
>
> in this sutuation R1, R6 and R4 are all on the same switch and in the same
> area 10. They are all configured with point-to-multipoint. The switchports
> for R1 and R4 are configured with "switchport protected." Since area 104
> lys on the other side of R4 a virutal link is required through area 10.
>
> A debug on R1 showed that it was only getting hellos from R6.
>
> R1#
> *May 24 14:04:36.612: OSPF: Rcv hello from 172.16.106.1 area 10 from
> FastEthernet0/1 172.16.10.6
> *May 24 14:04:36.612: OSPF: End of hello processing
> R1#
> *May 24 14:04:56.484: OSPF: Send hello to 224.0.0.5 area 10 on
> FastEthernet0/1 from 172.16.10.1
> R1#
> *May 24 14:05:05.736: OSPF: Rcv hello from 172.16.106.1 area 10 from
> FastEthernet0/1 172.16.10.6
> *May 24 14:05:05.736: OSPF: End of hello processing
>
> When I did a show ip os neigh on R1 and R4 they both only have R6 as
> neighbors.
>
> R1(config-router)#do s ip os neig
> Neighbor ID Pri State Dead Time Address Interface
> 172.16.102.1 0 FULL/ - 00:00:38 172.16.21.2
> FastEthernet0/0
> 172.16.104.1 0 FULL/ - - 172.16.10.4 *OSPF_VL0*
> 172.16.106.1 0 FULL/ - 00:01:34 172.16.10.6
> FastEthernet0/1
>
> In the mean time both R4 and R1 have virtual links configured directly to
> each other and the virtual link's adjacency state is full?
>
> So - how is it that? Is the virtual link being routed via R6. It would
> have to be.
>
> R1#sho ip os virtual
> Virtual Link OSPF_VL0 to router 172.16.104.1 is up
> Run as demand circuit
> DoNotAge LSA allowed.
> Transit area 10, via interface FastEthernet0/1, Cost of using 2
> Transmit Delay is 1 sec, State POINT_TO_POINT,
> Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
> Hello due in 00:00:08
> Adjacency State FULL (Hello suppressed)
> Index 2/3, retransmission queue length 0, number of retransmission 0
> First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
> Last retransmission scan length is 0, maximum is 0
> Last retransmission scan time is 0 msec, maximum is 0 msec
> Message digest authentication enabled
> Youngest key id is 1
>
> So in the end I have a question about the best practice for virtual links.
> On a multiaccess network as in area 10, if there are no other elements like
> ports are protected and we are dealing with a plain old vanilla area 10 and
> needs to be a transit for a VL where should the end points be?
>
> Should the VL go from R1-R6 and R6 to R4? or just R1-R4?
>
> I've seen scenarios where the vl went from r1-r6 and r6-r4. But I can only
> think that that would be needed if R6 was an ABR as well.
>
> Thoughts?
>
>
> r/
> LG
>
>
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Received on Mon May 24 2010 - 10:42:48 ART