RE: IEWB CORE Lab3 Virtual link

From: Scott Morris (swm@emanon.com)
Date: Mon Aug 21 2006 - 20:29:39 ART


You sure about that? It would violate RFC (IMHO), and doesn't jive with the
code I'm using....

R2
interface Loopback0
 ip address 22.22.22.22 255.255.255.0
interface FastEthernet1/0
 no switchport
 ip address 11.11.11.2 255.255.255.0
router ospf 1
 router-id 2.2.2.2
 log-adjacency-changes
 area 11 virtual-link 1.1.1.1
 network 11.11.11.2 0.0.0.0 area 11
 network 22.22.22.22 0.0.0.0 area 22

R1
interface Loopback0
 ip address 12.12.12.12 255.255.255.0
interface Loopback1
 ip address 111.111.111.111 255.255.255.0
interface FastEthernet0/0
 ip address 11.11.11.1 255.255.255.0
 duplex auto
 speed auto
router ospf 1
 router-id 1.1.1.1
 log-adjacency-changes
 area 11 virtual-link 2.2.2.2
 network 11.11.11.1 0.0.0.0 area 11
 network 12.12.12.12 0.0.0.0 area 12

R1(config-router)#do sh ip o v
Virtual Link OSPF_VL0 to router 2.2.2.2 is down
  Run as demand circuit
  DoNotAge LSA allowed.
  Transit area 11, Cost of using 65535
  Transmit Delay is 1 sec, State DOWN,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
R1(config-router)#

R1(config-router)#do sh ip o d

            OSPF Router with ID (1.1.1.1) (Process ID 1)

                Router Link States (Area 11)

Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 44 0x80000003 0x00548F 1
2.2.2.2 2.2.2.2 49 0x80000009 0x000ACA 1

                Net Link States (Area 11)

Link ID ADV Router Age Seq# Checksum
11.11.11.2 2.2.2.2 50 0x80000001 0x0038CA

                Router Link States (Area 12)

Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 54 0x80000001 0x0048B1 1
R1(config-router)#

Nothing in area 0 at all....

(15 minutes pass for good measure)

R1#sh ip o vi
Virtual Link OSPF_VL0 to router 2.2.2.2 is down
  Run as demand circuit
  DoNotAge LSA allowed.
  Transit area 11, Cost of using 65535
  Transmit Delay is 1 sec, State DOWN,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
R1#
R1#sh ip o d

            OSPF Router with ID (1.1.1.1) (Process ID 1)

                Router Link States (Area 11)

Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 779 0x80000003 0x00548F 1
2.2.2.2 2.2.2.2 784 0x80000009 0x000ACA 1

                Net Link States (Area 11)

Link ID ADV Router Age Seq# Checksum
11.11.11.2 2.2.2.2 785 0x80000001 0x0038CA

                Router Link States (Area 12)

Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 789 0x80000001 0x0048B1 1
R1#

Still nothing.

R2#sh ip o v
Virtual Link OSPF_VL0 to router 1.1.1.1 is down
  Run as demand circuit
  DoNotAge LSA allowed.
  Transit area 11, Cost of using 65535
  Transmit Delay is 1 sec, State DOWN,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
R2#

Nothing here either.

R2#sh ip o i
OSPF_VL0 is down, line protocol is down
  Internet Address 0.0.0.0/0, Area 0
  Process ID 1, Router ID 2.2.2.2, Network Type VIRTUAL_LINK, Cost: 65535
  Configured as demand circuit.
  Run as demand circuit.
  DoNotAge LSA allowed.
  Transmit Delay is 1 sec, State DOWN,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
FastEthernet1/0 is up, line protocol is up
  Internet Address 11.11.11.2/24, Area 11
  Process ID 1, Router ID 2.2.2.2, Network Type BROADCAST, Cost: 1
  Transmit Delay is 1 sec, State DR, Priority 1
  Designated Router (ID) 2.2.2.2, Interface address 11.11.11.2
  Backup Designated router (ID) 1.1.1.1, Interface address 11.11.11.1
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:09
  Supports Link-local Signaling (LLS)
  Index 1/2, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 1
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 1.1.1.1 (Backup Designated Router)
  Suppress hello for 0 neighbor(s)
Loopback0 is up, line protocol is up
  Internet Address 22.22.22.22/24, Area 22
  Process ID 1, Router ID 2.2.2.2, Network Type LOOPBACK, Cost: 1
  Loopback interface is treated as a stub Host
R2#

R1#sh ip o i
OSPF_VL0 is down, line protocol is down
  Internet Address 0.0.0.0/0, Area 0
  Process ID 1, Router ID 1.1.1.1, Network Type VIRTUAL_LINK, Cost: 65535
  Configured as demand circuit.
  Run as demand circuit.
  DoNotAge LSA allowed.
  Transmit Delay is 1 sec, State DOWN,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
FastEthernet0/0 is up, line protocol is up
  Internet Address 11.11.11.1/24, Area 11
  Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 1
  Transmit Delay is 1 sec, State BDR, Priority 1
  Designated Router (ID) 2.2.2.2, Interface address 11.11.11.2
  Backup Designated router (ID) 1.1.1.1, Interface address 11.11.11.1
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:05
  Supports Link-local Signaling (LLS)
  Index 1/2, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 2
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 2.2.2.2 (Designated Router)
  Suppress hello for 0 neighbor(s)
Loopback0 is up, line protocol is up
  Internet Address 12.12.12.12/24, Area 12
  Process ID 1, Router ID 1.1.1.1, Network Type LOOPBACK, Cost: 1
  Loopback interface is treated as a stub Host
R1#

After we enable SOMETHING in Area 0 - things will work.

R1
router ospf 1
 network 111.111.111.111 0.0.0.0 area 0

R1(config-router)#
*Aug 21 23:15:28.361: OSPF: Interface Loopback1 going Up
*Aug 21 23:15:28.861: OSPF: Build router LSA for area 0, router ID 1.1.1.1,
seq 0x80000001
*Aug 21 23:15:28.861: OSPF: Build router LSA for area 11, router ID 1.1.1.1,
seq 0x80000004
*Aug 21 23:15:28.861: OSPF: Build router LSA for area 12, router ID 1.1.1.1,
seq 0x80000002
*Aug 21 23:15:29.981: OSPF: Rcv hello from 2.2.2.2 area 11 from
FastEthernet0/0 11.11.11.2
*Aug 21 23:15:29.981: OSPF: End of hello processing
*Aug 21 23:15:33.861: OSPF: Rcv hello from 2.2.2.2 area 0 from OSPF_VL0
11.11.11.2
*Aug 21 23:15:35.113: OSPF: Send hello to 224.0.0.5 area 11 on
FastEthernet0/0 from 11.11.11.1
*Aug 21 23:15:39.977: OSPF: Rcv hello from 2.2.2.2 area 11 from
FastEthernet0/0 11.11.11.2
*Aug 21 23:15:39.977: OSPF: End of hello processing
*Aug 21 23:15:43.365: OSPF: Interface OSPF_VL0 going Up
*Aug 21 23:15:43.365: OSPF: Send hello to 11.11.11.2 area 0 on OSPF_VL0 from
11.11.11.1
*Aug 21 23:15:43.857: OSPF: Rcv hello from 2.2.2.2 area 0 from OSPF_VL0
11.11.11.2
*Aug 21 23:15:43.861: OSPF: 2 Way Communication to 2.2.2.2 on OSPF_VL0,
state 2WAY
*Aug 21 23:15:43.861: OSPF: Send DBD to 2.2.2.2 on OSPF_VL0 seq 0x1CAC opt
0x72 flag 0x7 len 32
*Aug 21 23:15:43.861: OSPF: End of hello processing
*Aug 21 23:15:43.861: OSPF: Rcv DBD from 2.2.2.2 on OSPF_VL0 seq 0x2375 opt
0x72 flag 0x7 len 32 mtu 0 state EXSTART
*Aug 21 23:15:43.861: OSPF: NBR Negotiation Done. We are the SLAVE
*Aug 21 23:15:43.861: OSPF: Send DBD to 2.2.2.2 on OSPF_VL0 seq 0x2375 opt
0x72 flag 0x2 len 92
*Aug 21 23:15:43.861: OSPF: Rcv DBD from 2.2.2.2 on OSPF_VL0 seq 0x2376 opt
0x72 flag 0x3 len 92 mtu 0 state EXCHANGE
*Aug 21 23:15:43.865: OSPF: Send DBD to 2.2.2.2 on OSPF_VL0 seq 0x2376 opt
0x72 flag 0x0 len 32
*Aug 21 23:15:43.865: OSPF: Database request to 2.2.2.2
*Aug 21 23:15:43.865: OSPF: sent LS REQ packet to 11.11.11.2, length 36
*Aug 21 23:15:43.865: OSPF: Rcv DBD from 2.2.2.2 on OSPF_VL0 seq 0x2377 opt
0x72 flag 0x1 len 32 mtu 0 state EXCHANGE
*Aug 21 23:15:43.865: OSPF: Exchange Done with 2.2.2.2 on OSPF_VL0
*Aug 21 23:15:43.865: OSPF: Send DBD to 2.2.2.2 on OSPF_VL0 seq 0x2377 opt
0x72 flag 0x0 len 32
*Aug 21 23:15:43.865: OSPF: Synchronized with 2.2.2.2 on OSPF_VL0, state
FULL
*Aug 21 23:15:43.869: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on OSPF_VL0
from LOADING to FULL, Loading Done
*Aug 21 23:15:44.369: OSPF: Build router LSA for area 11, router ID 1.1.1.1,
seq 0x80000005
*Aug 21 23:15:44.369: OSPF: Build router LSA for area 0, router ID 1.1.1.1,
seq 0x80000002
*Aug 21 23:15:45.113: OSPF: Send hello to 224.0.0.5 area 11 on
FastEthernet0/0 from 11.11.11.1
*Aug 21 23:15:49.977: OSPF: Rcv hello from 2.2.2.2 area 11 from
FastEthernet0/0 11.11.11.2
*Aug 21 23:15:49.977: OSPF: End of hello processing
R1(config-router)#

Magic happens now. The funny thing is that if you REMOVE the area 0
loopback from the process, the virtual link appear to remain up. But in
order to get it started, some other interface MUST be in area 0 as I would
expect.

The concept of a virtual link is to extend area 0 out to over another area
(transit) to a different ABR. In order to extend something, it must already
exist logically.

Even if I add the 111.111.111.111 back in as a new area, things still
continue to work:

R1(config-router)#network 111.111.111.111 0.0.0.0 area 111
R1(config-router)#
*Aug 21 23:21:32.501: OSPF: Interface Loopback1 going Up
*Aug 21 23:21:33.001: OSPF: Build router LSA for area 111, router ID
1.1.1.1, seq 0x80000001
R1(config-router)#

R2#
*Aug 21 23:20:17.705: RT: SET_LAST_RDB for 111.111.111.111/32
  NEW rdb: via 11.11.11.1

*Aug 21 23:20:17.705: RT: add 111.111.111.111/32 via 11.11.11.1, ospf metric
[110/2]
*Aug 21 23:20:17.709: RT: NET-RED 111.111.111.111/32
R2#

But nothing started without an area 0 interface in an up state.

I'm running 12.3(11r)T1 on a 3825, and 12.4(3a) on a 2811. *shrug*

 
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE
#153, CISSP, et al.
CCSI/JNCI-M/JNCI-J
IPExpert VP - Curriculum Development
IPExpert Sr. Technical Instructor
smorris@ipexpert.com
http://www.ipexpert.com
 
 

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Brian McGahan
Sent: Monday, August 21, 2006 3:52 PM
To: Tim Chan; slammer@broadpark.no; ccielab@groupstudy.com
Subject: RE: IEWB CORE Lab3 Virtual link

The virtual-link is area 0. You don't need a physical interface to be
assigned to area 0 for this to work.

Brian McGahan, CCIE #8593
bmcgahan@internetworkexpert.com

Internetwork Expert, Inc.
http://www.InternetworkExpert.com
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> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Tim Chan
> Sent: Monday, August 21, 2006 2:12 PM
> To: slammer@broadpark.no; ccielab@groupstudy.com
> Subject: Re: IEWB CORE Lab3 Virtual link
>
> I would agree that you need an area 0 to implement a virtual link.
But if
> you read in the IE
> forum, someone got this to work without an area 0 just by changing the
IOS
> to 12.2.15-T17.
>
>
>
> ----- Original Message ----
> From: slammer@broadpark.no
> To: ccielab@groupstudy.com
> Sent: Monday, August 21, 2006 11:14:52 AM
> Subject: IEWB CORE Lab3 Virtual link
>
> Is it necessary for at least one interface to be in area 0 on R3 in
order
> to fulfill task 4.5 and 4.8?
>
> RFC3509 seems to indicate that Cisco requires an ABR to have at least
one
> active interface in the backbone area in order for the VL,s to become
> active Cant get this thing working
>
> Help anyone !!!!!!!!!!!!!!!!
>
>



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