Re: can't access other networks from Vlan10 & vlan20 using OSPF

thirumg3 · ‎03-15-2023

I can't access other networks from vlan10 & vlan 20 but I can access vlan10,vlan 20 from other networks(OSPF routing protocol is used in my all routers).I can ping vlan10&20 from my BRANCH A router but not ping between the Vlan's (10&20).

For your reference

BRANCH_A#sh runn

Building configuration...

Current configuration : 1157 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname BRANCH_A

!

no ip cef

no ipv6 cef

!

license udi pid CISCO2811/K9 sn FTX101728HF-

!

spanning-tree mode pvst

!

interface FastEthernet0/0

ip address 172.16.1.1 255.255.255.252

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 172.16.1.5 255.255.255.252

duplex auto

speed auto

!

interface Ethernet1/0

no ip address

duplex auto

speed auto

!

interface Ethernet1/0.3

no ip address

!

interface Ethernet1/0.10

encapsulation dot1Q 10

ip address 10.1.10.2 255.255.255.0

!

interface Ethernet1/0.20

encapsulation dot1Q 20

ip address 10.1.20.2 255.255.255.0

!

interface Vlan1

no ip address

shutdown

!

router ospf 30

router-id 0.0.0.30

log-adjacency-changes

passive-interface Ethernet1/0.10

passive-interface Ethernet1/0.20

network 10.1.0.0 0.0.255.255 area 0

network 172.16.0.0 0.0.255.255 area 0

network 10.0.0.0 0.255.255.255 area 0

!

ip classless

!

ip flow-export version 9

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

end

VLAN10:

VLAN10#sh runn

Building configuration...

Current configuration : 1277 bytes

!

version 12.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname VLAN10

!

spanning-tree mode pvst

spanning-tree extend system-id

!

interface FastEthernet0/1

switchport trunk allowed vlan 1,10,20

switchport mode trunk

!

interface FastEthernet0/2

switchport mode trunk

!

interface FastEthernet0/3

switchport access vlan 10

switchport mode trunk

!

interface FastEthernet0/4

!

interface FastEthernet0/5

!

interface FastEthernet0/6

!

interface FastEthernet0/7

!

interface FastEthernet0/8

!

interface FastEthernet0/9

!

interface FastEthernet0/10

!

interface FastEthernet0/11

!

interface FastEthernet0/12

!

interface FastEthernet0/13

!

interface FastEthernet0/14

!

interface FastEthernet0/15

!

interface FastEthernet0/16

!

interface FastEthernet0/17

!

interface FastEthernet0/18

!

interface FastEthernet0/19

!

interface FastEthernet0/20

!

interface FastEthernet0/21

!

interface FastEthernet0/22

!

interface FastEthernet0/23

!

interface FastEthernet0/24

switchport trunk allowed vlan 1,10,20

switchport mode trunk

!

interface GigabitEthernet0/1

!

interface GigabitEthernet0/2

!

interface Vlan1

no ip address

shutdown

!

line con 0

!

line vty 0 4

login

line vty 5 15

login

!

end

VLAN20:

VLAN20#sh runn

Building configuration...

Current configuration : 1153 bytes

!

version 12.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname VLAN20

!

spanning-tree mode pvst

spanning-tree extend system-id

!

interface FastEthernet0/1

switchport mode trunk

!

interface FastEthernet0/2

switchport access vlan 20

switchport mode trunk

!

interface FastEthernet0/3

!

interface FastEthernet0/4

!

interface FastEthernet0/5

!

interface FastEthernet0/6

!

interface FastEthernet0/7

!

interface FastEthernet0/8

!

interface FastEthernet0/9

!

interface FastEthernet0/10

!

interface FastEthernet0/11

!

interface FastEthernet0/12

!

interface FastEthernet0/13

!

interface FastEthernet0/14

!

interface FastEthernet0/15

!

interface FastEthernet0/16

!

interface FastEthernet0/17

!

interface FastEthernet0/18

!

interface FastEthernet0/19

!

interface FastEthernet0/20

!

interface FastEthernet0/21

!

interface FastEthernet0/22

!

interface FastEthernet0/23

!

interface FastEthernet0/24

!

interface GigabitEthernet0/1

!

interface GigabitEthernet0/2

!

interface Vlan1

no ip address

shutdown

!

line con 0

!

line vty 0 4

login

line vty 5 15

login

!

end

BRANCH A:

BRANCH_A#sh ip route

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks

C 10.1.10.0/24 is directly connected, Ethernet1/0.10

L 10.1.10.2/32 is directly connected, Ethernet1/0.10

C 10.1.20.0/24 is directly connected, Ethernet1/0.20

L 10.1.20.2/32 is directly connected, Ethernet1/0.20

O 10.2.2.0/24 [110/12] via 172.16.1.6, 00:30:44, FastEthernet0/1

[110/12] via 172.16.1.2, 00:30:44, FastEthernet0/0

172.16.0.0/16 is variably subnetted, 6 subnets, 2 masks

C 172.16.1.0/30 is directly connected, FastEthernet0/0

L 172.16.1.1/32 is directly connected, FastEthernet0/0

C 172.16.1.4/30 is directly connected, FastEthernet0/1

L 172.16.1.5/32 is directly connected, FastEthernet0/1

O 172.16.1.8/30 [110/2] via 172.16.1.2, 00:30:54, FastEthernet0/0

O 172.16.1.12/30 [110/2] via 172.16.1.6, 00:30:54, FastEthernet0/1

O 192.168.1.0/24 [110/11] via 172.16.1.6, 00:30:54, FastEthernet0/1

O 192.168.2.0/24 [110/11] via 172.16.1.2, 00:30:54, FastEthernet0/0

BRANCH_A#sh ip prot

Routing Protocol is "ospf 30"

Outgoing update filter list for all interfaces is not set

Incoming update filter list for all interfaces is not set

Router ID 0.0.0.30

Number of areas in this router is 1. 1 normal 0 stub 0 nssa

Maximum path: 4

Routing for Networks:

10.1.0.0 0.0.255.255 area 0

172.16.0.0 0.0.255.255 area 0

10.0.0.0 0.255.255.255 area 0

Passive Interface(s):

Ethernet1/0.10

Ethernet1/0.20

Routing Information Sources:

Gateway Distance Last Update

0.0.0.1 110 00:01:46

0.0.0.4 110 00:01:46

0.0.0.20 110 00:01:47

0.0.0.30 110 00:01:51

Distance: (default is 110)

BRANCH_A#sh ip ospf neigh

Neighbor ID Pri State Dead Time Address Interface

0.0.0.4 1 FULL/BDR 00:00:36 172.16.1.2 FastEthernet0/0

0.0.0.20 1 FULL/BDR 00:00:37 172.16.1.6 FastEthernet0/1

BRANCH_A#show ip ospf database

OSPF Router with ID (0.0.0.30) (Process ID 30)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count

0.0.0.30 0.0.0.30 313 0x80000008 0x00891f 4

0.0.0.20 0.0.0.20 309 0x80000007 0x0091e4 3

0.0.0.4 0.0.0.4 308 0x80000007 0x009213 3

0.0.0.1 0.0.0.1 308 0x80000007 0x006986 3

Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

172.16.1.5 0.0.0.30 313 0x80000003 0x005b8a

172.16.1.1 0.0.0.30 313 0x80000004 0x00f1f6

172.16.1.13 0.0.0.20 309 0x80000002 0x00b536

172.16.1.9 0.0.0.4 308 0x80000002 0x00838c

MHM Cisco World · ‎03-15-2023

You can not ping from VLAN to VLAN because as I see you dont config IP for VLAN (SVI)
and this also need config GW in each PC point to SVI of VLAN in each sites

thirumg3 · ‎03-15-2023

PFA

balaji.bandi · ‎03-15-2023

I want to break down your problem and ask questions here :

I can't access other networks from vlan10 & vlan 20 - what is the other networks ? any IP address ?

but I can access vlan10,vlan 20 from other networks(OSPF routing protocol is used in my all routers) - You can access VLAN 10 and 20, Gateway IP address or end device IP address ( example from what networks you able to access and show some output~) ?

I can ping vlan10&20 from my BRANCH A router but not ping between the Vlan's (10&20). - Branch A having Layer 3 Interface ? are you able to ping end device in that VLAN 10 and 20 ?

have you checked end device have FW

Test output required :

1. Post all the router config - along with show ip route

2. show ip arp from Branch A Router

3. Traceroute from VLAN 10 and 20 output.

4. If you enabled OSPF all Routers as per your diagram,, i am sure i see some OSPF loop here. (on branchA router can you shutdown one of the interface (any one fas 0/0 or fas 0/1 ) do the testings.

5. show ip ospf neigh from all routers.

BB

***** Rate All Helpful Responses *****

How to Ask The Cisco Community for Help

thirumg3 · ‎03-15-2023

I can't access other networks from vlan10 & vlan 20 - what is the other
networks ? any IP address ?
*ROUTERS: N/T IP*
BRANCH_B -192.168.1.0/24 (192.168.1.2)
BRANCH_C-192.168.2.0/24 (192.168.2.2)
HQ -10.2.2.0/24 (10.2.2.100 , 10.2.2.2.101
,10.2.2.2.200)

but I can access vlan10,vlan 20 from other networks(OSPF routing protocol
is used in my all routers) - You can access VLAN 10 and 20, Gateway IP
address or end device IP address ( example from what networks you able to
access and show some output~) ?
[image: image.png]

[image: image.png]
I can ping vlan10&20 from my BRANCH A router but not ping between the
Vlan's (10&20). - Branch A having Layer 3 Interface ? are you able to ping
end device in that VLAN 10 and 20 ?

[image: image.png]

have you checked end device have FW
I have checked no FW in my end device.

*Test output required
1. Post all the router config - along with show ip route

BRANCH_A#sh runn

Building configuration...

Current configuration : 1157 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname BRANCH_A

!

!

!

!

!

!

!

!

no ip cef

no ipv6 cef

!

!

!

!

license udi pid CISCO2811/K9 sn FTX101728HF-

!

!

!

!

!

!

!

!

!

!

!

spanning-tree mode pvst

!

!

!

!

!

!

interface FastEthernet0/0

ip address 172.16.1.1 255.255.255.252

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 172.16.1.5 255.255.255.252

duplex auto

speed auto

!

interface Ethernet1/0

no ip address

duplex auto

speed auto

!

interface Ethernet1/0.3

no ip address

!

interface Ethernet1/0.10

encapsulation dot1Q 10

ip address 10.1.10.2 255.255.255.0

!

interface Ethernet1/0.20

encapsulation dot1Q 20

ip address 10.1.20.2 255.255.255.0

!

interface Vlan1

no ip address

shutdown

!

router ospf 30

router-id 0.0.0.30

log-adjacency-changes

passive-interface Ethernet1/0.10

passive-interface Ethernet1/0.20

network 10.1.0.0 0.0.255.255 area 0

network 172.16.0.0 0.0.255.255 area 0

network 10.0.0.0 0.255.255.255 area 0

!

ip classless

!

ip flow-export version 9

!

!

!

!

!

!

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

BRANCH_A#sh ip route

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks

C 10.1.10.0/24 is directly connected, Ethernet1/0.10

L 10.1.10.2/32 is directly connected, Ethernet1/0.10

C 10.1.20.0/24 is directly connected, Ethernet1/0.20

L 10.1.20.2/32 is directly connected, Ethernet1/0.20

O 10.2.2.0/24 [110/12] via 172.16.1.6, 00:47:23, FastEthernet0/1

[110/12] via 172.16.1.2, 00:47:23, FastEthernet0/0

172.16.0.0/16 is variably subnetted, 6 subnets, 2 masks

C 172.16.1.0/30 is directly connected, FastEthernet0/0

L 172.16.1.1/32 is directly connected, FastEthernet0/0

C 172.16.1.4/30 is directly connected, FastEthernet0/1

L 172.16.1.5/32 is directly connected, FastEthernet0/1

O 172.16.1.8/30 [110/2] via 172.16.1.2, 00:47:23, FastEthernet0/0

O 172.16.1.12/30 [110/2] via 172.16.1.6, 00:47:23, FastEthernet0/1

O 192.168.1.0/24 [110/11] via 172.16.1.6, 00:47:23, FastEthernet0/1

O 192.168.2.0/24 [110/11] via 172.16.1.2, 00:47:23, FastEthernet0/0

BRANCH_B#sh runn

Building configuration...

Current configuration : 860 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname BRANCH_B

!

!

!

!

!

!

!

!

no ip cef

no ipv6 cef

!

!

!

!

license udi pid CISCO2811/K9 sn FTX1017QX79-

!

!

!

!

!

!

!

!

!

!

!

spanning-tree mode pvst

!

!

!

!

!

!

interface FastEthernet0/0

ip address 172.16.1.6 255.255.255.252

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 172.16.1.13 255.255.255.252

duplex auto

speed auto

!

interface Ethernet1/0

ip address 192.168.1.1 255.255.255.0

duplex auto

speed auto

!

interface Vlan1

no ip address

shutdown

!

router ospf 20

router-id 0.0.0.20

log-adjacency-changes

network 192.168.1.0 0.0.0.255 area 0

network 172.16.0.0 0.0.255.255 area 0

!

ip classless

!

ip flow-export version 9

!

!

!

!

!

!

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

BRANCH_B#sh ip route

Gateway of last resort is not set

10.0.0.0/24 is subnetted, 3 subnets

O 10.1.10.0/24 [110/2] via 172.16.1.5, 00:49:53, FastEthernet0/0

O 10.1.20.0/24 [110/2] via 172.16.1.5, 00:49:53, FastEthernet0/0

O 10.2.2.0/24 [110/11] via 172.16.1.14, 00:49:53, FastEthernet0/1

172.16.0.0/16 is variably subnetted, 6 subnets, 2 masks

O 172.16.1.0/30 [110/2] via 172.16.1.5, 00:49:53, FastEthernet0/0

C 172.16.1.4/30 is directly connected, FastEthernet0/0

L 172.16.1.6/32 is directly connected, FastEthernet0/0

O 172.16.1.8/30 [110/2] via 172.16.1.14, 00:49:53, FastEthernet0/1

C 172.16.1.12/30 is directly connected, FastEthernet0/1

L 172.16.1.13/32 is directly connected, FastEthernet0/1

192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.1.0/24 is directly connected, Ethernet1/0

L 192.168.1.1/32 is directly connected, Ethernet1/0

O 192.168.2.0/24 [110/12] via 172.16.1.5, 00:49:53, FastEthernet0/0

[110/12] via 172.16.1.14, 00:49:53, FastEthernet0/1

BRANCH_C#sh runn

Building configuration...

Current configuration : 858 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname BRANCH_C

!

!

!

!

!

!

!

!

no ip cef

no ipv6 cef

!

!

!

!

license udi pid CISCO2811/K9 sn FTX1017Q5R1-

!

!

!

!

!

!

!

!

!

!

!

spanning-tree mode pvst

!

!

!

!

!

!

interface FastEthernet0/0

ip address 172.16.1.2 255.255.255.252

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 172.16.1.9 255.255.255.252

duplex auto

speed auto

!

interface Ethernet1/0

ip address 192.168.2.1 255.255.255.0

duplex auto

speed auto

!

interface Vlan1

no ip address

shutdown

!

router ospf 50

router-id 0.0.0.4

log-adjacency-changes

network 172.16.0.0 0.0.255.255 area 0

network 192.168.2.0 0.0.0.255 area 0

!

ip classless

!

ip flow-export version 9

!

!

!

!

!

!

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

BRANCH_C#sh ip route

Gateway of last resort is not set

10.0.0.0/24 is subnetted, 3 subnets

O 10.1.10.0/24 [110/2] via 172.16.1.1, 00:51:16, FastEthernet0/0

O 10.1.20.0/24 [110/2] via 172.16.1.1, 00:51:16, FastEthernet0/0

O 10.2.2.0/24 [110/11] via 172.16.1.10, 00:51:16, FastEthernet0/1

172.16.0.0/16 is variably subnetted, 6 subnets, 2 masks

C 172.16.1.0/30 is directly connected, FastEthernet0/0

L 172.16.1.2/32 is directly connected, FastEthernet0/0

O 172.16.1.4/30 [110/2] via 172.16.1.1, 00:51:16, FastEthernet0/0

C 172.16.1.8/30 is directly connected, FastEthernet0/1

L 172.16.1.9/32 is directly connected, FastEthernet0/1

O 172.16.1.12/30 [110/2] via 172.16.1.10, 00:51:16, FastEthernet0/1

O 192.168.1.0/24 [110/12] via 172.16.1.1, 00:51:16, FastEthernet0/0

[110/12] via 172.16.1.10, 00:51:16, FastEthernet0/1

192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.2.0/24 is directly connected, Ethernet1/0

L 192.168.2.1/32 is directly connected, Ethernet1/0

HQ#sh runn

Building configuration...

Current configuration : 899 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname HQ

!

!

!

!

!

!

!

!

no ip cef

no ipv6 cef

!

!

!

!

license udi pid CISCO2811/K9 sn FTX1017ZD9L-

!

!

!

!

!

!

!

!

!

!

!

spanning-tree mode pvst

!

!

!

!

!

!

interface FastEthernet0/0

ip address 172.16.1.10 255.255.255.252

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 172.16.1.14 255.255.255.252

duplex auto

speed auto

!

interface Ethernet1/0

ip address 10.2.2.1 255.255.255.0

duplex auto

speed auto

!

interface Vlan1

no ip address

shutdown

!

router ospf 1

router-id 0.0.0.1

log-adjacency-changes

network 172.16.0.0 0.0.255.255 area 0

network 10.2.2.0 0.0.0.255 area 0

network 10.0.0.0 0.255.255.255 area 0

!

ip classless

!

ip flow-export version 9

!

!

!

no cdp run

!

!

!

!

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

HQ#sh ip route

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks

O 10.1.10.0/24 [110/3] via 172.16.1.9, 00:53:24, FastEthernet0/0

[110/3] via 172.16.1.13, 00:53:24, FastEthernet0/1

O 10.1.20.0/24 [110/3] via 172.16.1.9, 00:53:24, FastEthernet0/0

[110/3] via 172.16.1.13, 00:53:24, FastEthernet0/1

C 10.2.2.0/24 is directly connected, Ethernet1/0

L 10.2.2.1/32 is directly connected, Ethernet1/0

172.16.0.0/16 is variably subnetted, 6 subnets, 2 masks

O 172.16.1.0/30 [110/2] via 172.16.1.9, 00:53:24, FastEthernet0/0

O 172.16.1.4/30 [110/2] via 172.16.1.13, 00:53:24, FastEthernet0/1

C 172.16.1.8/30 is directly connected, FastEthernet0/0

L 172.16.1.10/32 is directly connected, FastEthernet0/0

C 172.16.1.12/30 is directly connected, FastEthernet0/1

L 172.16.1.14/32 is directly connected, FastEthernet0/1

O 192.168.1.0/24 [110/11] via 172.16.1.13, 00:53:24, FastEthernet0/1

O 192.168.2.0/24 [110/11] via 172.16.1.9, 00:53:24, FastEthernet0/0

*2. show ip arp from Branch A Router:*

BRANCH_A#sh ip arp

Protocol Address Age (min) Hardware Addr Type Interface

Internet 172.16.1.1 - 0000.0C9A.1C01 ARPA FastEthernet0/0

Internet 172.16.1.2 55 00D0.9728.9E01 ARPA FastEthernet0/0

Internet 172.16.1.5 - 0000.0C9A.1C02 ARPA FastEthernet0/1

Internet 172.16.1.6 55 0060.3E29.2401 ARPA FastEthernet0/1

*3. Traceroute from VLAN 10 and 20 output:*

[image: image.png]

[image: image.png]

*4. If you enabled OSPF all Routers as per your diagram,, i am sure i see
some OSPF loop here. (on branchA router can you shutdown one of the
interface (any one fas 0/0 or fas 0/1 ) do the testings.*

BRANCH_A#conf t

Enter configuration commands, one per line. End with CNTL/Z.

BRANCH_A(config)#int f0/0

BRANCH_A(config-if)#shutdown

BRANCH_A(config-if)#

%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to
administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed
state to down

01:12:11: %OSPF-5-ADJCHG: Process 30, Nbr 0.0.0.4 on FastEthernet0/0 from
FULL to DOWN, Neighbor Down: Interface down or detached

BRANCH_A(config-if)#exit
[image: c19213f5-6efb-49b0-b562-adfee5da45d2.png]
[image: image.png][image: 568e10f6-64bc-48ff-88ec-44230ce48953.png]
[image: image.png]

*5. show ip ospf neigh from all routers.*

BRANCH_A>en

BRANCH_A#sh ip ospf neig

Neighbor ID Pri State Dead Time Address Interface

0.0.0.20 1 FULL/BDR 00:00:34 172.16.1.6 FastEthernet0/1

BRANCH_A#config t

Enter configuration commands, one per line. End with CNTL/Z.

BRANCH_A(config)#int f0/0

BRANCH_A(config-if)#no shutdown

BRANCH_A(config-if)#

%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed
state to up

BRANCH_A(config-if)#exit

BRANCH_A(config)#do sh ip ospf neigh

Neighbor ID Pri State Dead Time Address Interface

0.0.0.4 1 2WAY/DROTHER 00:00:36 172.16.1.2 FastEthernet0/0

0.0.0.20 1 FULL/BDR 00:00:30 172.16.1.6 FastEthernet0/1

BRANCH_B#sh ip ospf nei

Neighbor ID Pri State Dead Time Address Interface

0.0.0.1 1 FULL/BDR 00:00:34 172.16.1.14 FastEthernet0/1

0.0.0.30 1 FULL/DR 00:00:35 172.16.1.5 FastEthernet0/0

BRANCH_C>en

BRANCH_C#sh ip ospf neig

Neighbor ID Pri State Dead Time Address Interface

0.0.0.1 1 FULL/BDR 00:00:31 172.16.1.10 FastEthernet0/1

0.0.0.30 1 FULL/DR 00:00:37 172.16.1.1 FastEthernet0/0

HQ#sh ip ospf nei

Neighbor ID Pri State Dead Time Address Interface

0.0.0.4 1 FULL/DR 00:00:32 172.16.1.9 FastEthernet0/0

0.0.0.20 1 FULL/DR 00:00:31 172.16.1.13 FastEthernet0/1