Instance resolution verification in the glasstub Region

China site STUBAfter the region is set, the router will not send a query message to the STUB region when the route entry is lost. In the top area above, we can make the Rc into the STUB region, if the Rb loop0 port is down, the Rb will not send a query message to the Rc. We first enable all the vrouters of the three routers, and all the interfaces are involved. When the stub is not set, the route table is obtained as follows:

 
 

  
  
RA：  
  
  
1.0.0.0/24 is subnetted, 1 subnets  
  
  
C       1.1.1.0 is directly connected, Loopback0  
  
  
2.0.0.0/24 is subnetted, 1 subnets  
  
  
D       2.2.2.0 [90/2297000] via 12.1.1.2, 00:01:26, Serial2/1  
  
  
3.0.0.0/24 is subnetted, 1 subnets  
  
  
D       3.3.3.0 [90/2297000] via 12.1.1.2, 00:00:37, Serial2/1  
  
  
23.0.0.0/30 is subnetted, 1 subnets  
  
  
D       23.1.1.0 [90/2297000] via 12.1.1.2, 00:01:26, Serial2/1  
  
  
12.0.0.0/30 is subnetted, 1 subnets  
  
  
C       12.1.1.0 is directly connected, Serial2/1 
 
 

 
 

  
  
Rb：  
  
  
1.0.0.0/24 is subnetted, 1 subnets  
  
  
D       1.1.1.0 [90/2297000] via 12.1.1.1, 00:02:30, Serial2/1  
  
  
2.0.0.0/24 is subnetted, 1 subnets  
  
  
C       2.2.2.0 is directly connected, Loopback0  
  
  
3.0.0.0/24 is subnetted, 1 subnets  
  
  
D       3.3.3.0 [90/2297000] via 23.1.1.1, 00:01:41, Serial2/2  
  
  
23.0.0.0/30 is subnetted, 1 subnets  
  
  
C       23.1.1.0 is directly connected, Serial2/2  
  
  
12.0.0.0/30 is subnetted, 1 subnets  
  
  
C       12.1.1.0 is directly connected, Serial2/1 
 
 

 
 

  
  
Rc:  
  
  
1.0.0.0/24 is subnetted, 1 subnets  
  
  
D       1.1.1.0 [90/2297000] via 23.1.1.2, 00:02:06, Serial2/2  
  
  
2.0.0.0/24 is subnetted, 1 subnets  
  
  
D       2.2.2.0 [90/2297000] via 23.1.1.2, 00:02:06, Serial2/2  
  
  
3.0.0.0/24 is subnetted, 1 subnets  
  
  
C       3.3.3.0 is directly connected, Loopback0  
  
  
23.0.0.0/30 is subnetted, 1 subnets  
  
  
C       23.1.1.0 is directly connected, Serial2/2  
  
  
12.0.0.0/30 is subnetted, 1 subnets  
  
  
D       12.1.1.0 [90/2297000] via 23.1.1.2, 00:02:06, Serial2/2 
 
 

Next, let's start the experiment. When stub is not set on Rc, open debug on Rb.

 
 

  
  
RB # debug OSPF packets query
  
  
RB vintage Packets debugging is on
  
  
(QUERY)
  
  
RB # config t
  
  
Enter configuration commands, one per line. End with CNTL/Z.
  
  
RB (config )#
  
  
RB (config) # int loopback 0
  
  
RB (config-if) # shu
  
  
* Mar 1 00:16:38. 587: KERBEROS: Enqueueing QUERY on serial/1 iidbQ un/rely 0/1 serno 6-6
  
  
* Mar 1 00:16:38. 591: KERBEROS: Enqueueing QUERY on serial/1 nbr 12.1.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 6-6
  
  
* Mar 1 00:16:38. 599: KERBEROS: Sending QUERY on serial/1 nbr 12.1.1.1 send QUERY to RA)
  
  
* Mar 1 00:16:38. 603: AS 10, Flags 0x0, Seq 10/3 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 6-6
  
  
* Mar 1 00:16:38. 607: KERBEROS: Enqueueing QUERY on serial/2 iidbQ un/rely 0/1 serno 6-6
  
  
* Mar 1 00:16:38. 611: KERBEROS: Enqueueing QUERY on serial/2 nbr 23.1.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 6-6
  
  
* Mar 1 00:16:38. 619: KERBEROS: Sending QUERY on serial/2 nbr 23.1.1.1 send QUERY to RC)
  
  
* Mar 1 00:16:38. 623: AS 10, Flags 0x0, Seq 11/3 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 6-6
 
 

We can see that when stub is not set, Rb will send query messages to RA and Rc. Next we will make Rc into the STUB area.

First, we open the loopback 0 on RB to bring the network back to normal convergence.

 
 

  
  
Rbconfig-it）# int lo 0  
  
  
Rbconfig-it）#no sh 
 
 

Then, set RC to the STUB area.

 
 

  
  
RC(config)#router ei 100  
  
  
RC(config-router)#eigrp stub receive-only 
 
 

Turn off the loopback 0 on RB.

Let's look at the RB query:

 
 

  
  
* Mar 1 00:28:13. 139: KERBEROS: Enqueueing QUERY on serial/2 iidbQ un/rely 0/1 serno 9-9
  
  
* Mar 1 00: 28:13. 143: KERBEROS: Enqueueing QUERY on serial/2 nbr 23.1.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 9-9
  
  
* Mar 1 00: 28:13. 151: KERBEROS: Enqueueing QUERY on serial/1 iidbQ un/rely 0/1 serno 9-9
  
  
* Mar 1 00: 28:13. 155: KERBEROS: Enqueueing QUERY on serial/1 nbr 12.1.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 9-9
  
  
* Mar 1 00: 28:13. 163: KERBEROS: Sending QUERY on serial/1 nbr 12.1.1.1 send QUERY to RA)
  
  
* Mar 1 00: 28:13. 163: AS 10, Flags 0x0, Seq 19/8 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 9-9
  
  
* Mar 1 00: 28:13. 351: KERBEROS: Replicated ed QUERY on serial/2 nbr 23.1.1.1
  
  
RB (config-if )#
  
  
* Mar 1 00: 28:13. 355: AS 10, Flags 0x0, Seq 11/21 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
 
 

No query message to the Rc was found from beginning to end.