Totally Stub Area Communication

[Rinam Shah]

Hi, I am unable to ping the PC1 (area 0) from PC4 (totally stubby area). Please find the below packet tracer config.

I have done the below configuration in the cisco packet tracer.

1. Create two new VLANs (10 and 20) on Switches, set two trunk links between the switches. 

2. Set up inter-VLAN routing by SwitchA and HQ so that the three PCs in three different VLANs can PING each other. 

3. Apply switch port security to harden PC1/2/3 switch access. 

4. Apply OSPF with two areas as shown in the network map. Make HQ as DR and GW as BDR in the Ethernet segment. Make Area      10 as totally stubby area, and verify the Branch’s routing table to see if there is only one default route as OSPF route entry. Test      PC4 to any other PCs IP connectivity.

HQ:

interface FastEthernet0/0

ip address 172.16.1.1 255.255.255.252

ip ospf priority 10

duplex auto

speed auto

!

interface FastEthernet0/1

no ip address

duplex auto

speed auto

!

interface FastEthernet0/1.1

encapsulation dot1Q 1 native

ip address 192.168.1.2 255.255.255.0

!

interface FastEthernet0/1.10

encapsulation dot1Q 10

ip address 192.168.10.2 255.255.255.0

!

interface FastEthernet0/1.20

encapsulation dot1Q 20

ip address 192.168.20.2 255.255.255.0

!

router ospf 100

log-adjacency-changes

network 172.16.1.0 0.0.0.3 area 0

network 192.168.1.0 0.0.0.255 area 0

network 192.168.10.0 0.0.0.255 area 0

network 192.168.20.0 0.0.0.255 area 0

!

GW:

!

interface FastEthernet0/0

no ip address

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 172.16.1.2 255.255.255.252

ip ospf priority 5

duplex auto

speed auto

!

interface Serial0/0/0

ip address 172.16.2.1 255.255.255.252

clock rate 2000000

!

interface Serial0/0/1

no ip address

clock rate 2000000

!

interface Vlan1

no ip address

!

router ospf 100

log-adjacency-changes

area 10 stub no-summary

network 172.16.1.0 0.0.0.3 area 0

network 172.16.2.0 0.0.0.3 area 10

!

Branch:

!

interface FastEthernet0/0

ip address 172.16.3.1 255.255.255.240

duplex auto

speed auto

!

interface FastEthernet0/1

no ip address

duplex auto

speed auto

!

interface Serial0/0/0

ip address 172.16.2.2 255.255.255.252

!

interface Serial0/0/1

no ip address

clock rate 2000000

!

interface Vlan1

no ip address

!

router ospf 100

log-adjacency-changes

area 10 stub

network 172.16.2.0 0.0.0.3 area 10

network 172.16.3.0 0.0.0.15 area 10

!

SwitchA:

!

interface FastEthernet0/1

switchport mode trunk

!

interface FastEthernet0/2

switchport access vlan 10

!

interface FastEthernet0/3

switchport access vlan 20

!

interface FastEthernet0/4

switchport mode trunk

!

interface FastEthernet0/5

switchport mode trunk

!

[balaji.bandi]

The first question from PC are you able to ping the Branch network IP address ? 192.168.3.1 ? start from there.

is the OSPF neighbourship in all routers?

on the HQ  are you able to see the OSPF routes which were announced in GW ? and GW can see Branch routes?

[Rinam Shah]

Yes, I am able to ping all PCs from the Branch Router as below.

Branch#ping 172.16.3.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.16.3.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 0/4/21 ms

Branch#ping 192.168.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 2/16/30 ms

Branch#ping 192.168.10.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.10.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/19/25 ms

Branch#ping 192.168.20.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.20.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/4/19 ms

[Rinam Shah · Accepted solution]

Hi, The issue is auto-resolved without any config changes. Earlier HQ and GW router didn't receive PC4 route in the routing table. All I did was to run the simulation in packet tracer and once PC 4 ARP registered and route entered in the routing table, I am able to communicate between all PCs.

Thanks for the help.