Solved: routers using RIP cannot ping each other being in the same vlan

rehnumarahmat · ‎03-17-2025

Hi, I came accross this problem that Router 0 (Kodad) and Router 3 (Pargi) has a common vlan (Vlan 1) , where its network address is 158.75.8.192/26. it is a part of the larger corporate network 158.75.0.0/16. I have turned off auto0summarization for RIPv2 in both of them. every device can ping its own router, gateway router (R1) and ISP (R2) . Router 0 can ping other interfaces of Router 3 except for the interface belonging in vlan1 (158.75.8.221) and the switch (158.75.8.220) and vise-versa in case of router3. They both have their default route to the gateway router.

Running config of R0:

Building configuration...

Current configuration : 1126 bytes

!

version 15.4

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname kodad_R1

!

no ip cef

no ipv6 cef

!

no ip domain-lookup

!

spanning-tree mode pvst

!

interface GigabitEthernet0/0/0

no ip address

duplex auto

speed auto

shutdown

!

interface GigabitEthernet0/0/1

no ip address

duplex auto

speed auto

!

interface GigabitEthernet0/0/1.1

encapsulation dot1Q 1 native

ip address 158.75.8.194 255.255.255.192

!

interface GigabitEthernet0/0/1.715

encapsulation dot1Q 715

ip address 158.75.0.1 255.255.248.0

!

interface Serial0/1/0

ip address 158.75.9.33 255.255.255.252

!

interface Serial0/1/1

ip address 158.75.9.37 255.255.255.252

!

interface Serial0/2/0

no ip address

clock rate 2000000

shutdown

!

interface Serial0/2/1

no ip address

clock rate 2000000

shutdown

!

interface Vlan1

no ip address

shutdown

!

router rip

version 2

network 158.75.0.0

no auto-summary

!

ip classless

!

ip flow-export version 9

!

line con 0

exec-timeout 0 0

!

line aux 0

!

line vty 0 4

login

!

end

IP protocol of R0:

Routing Protocol is "rip"

Sending updates every 30 seconds, next due in 9 seconds

Invalid after 180 seconds, hold down 180, flushed after 240

Outgoing update filter list for all interfaces is not set

Incoming update filter list for all interfaces is not set

Redistributing: rip

Default version control: send version 2, receive 2

Interface Send Recv Triggered RIP Key-chain

Serial0/1/0 22

GigabitEthernet0/0/1.122

GigabitEthernet0/0/1.71522

Serial0/1/1 22

Automatic network summarization is not in effect

Maximum path: 4

Routing for Networks:

158.75.0.0

Passive Interface(s):

Routing Information Sources:

Gateway Distance Last Update

158.75.9.38 120 00:00:17

158.75.9.34 120 00:00:09

Distance: (default is 120)

Routing table of R0:

kodad_R1# sh ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP

i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area

* - candidate default, U - per-user static route, o - ODR

P - periodic downloaded static route

Gateway of last resort is 158.75.9.38 to network 0.0.0.0

158.75.0.0/16 is variably subnetted, 12 subnets, 6 masks

C 158.75.0.0/21 is directly connected, GigabitEthernet0/0/1.715

L 158.75.0.1/32 is directly connected, GigabitEthernet0/0/1.715

R 158.75.8.0/25 [120/1] via 158.75.9.34, 00:00:03, Serial0/1/0

R 158.75.8.128/26 [120/1] via 158.75.9.34, 00:00:03, Serial0/1/0

C 158.75.8.192/26 is directly connected, GigabitEthernet0/0/1.1

L 158.75.8.194/32 is directly connected, GigabitEthernet0/0/1.1

R 158.75.9.0/27 [120/1] via 158.75.9.38, 00:00:06, Serial0/1/1

C 158.75.9.32/30 is directly connected, Serial0/1/0

L 158.75.9.33/32 is directly connected, Serial0/1/0

C 158.75.9.36/30 is directly connected, Serial0/1/1

L 158.75.9.37/32 is directly connected, Serial0/1/1

R 158.75.9.40/30 [120/1] via 158.75.9.34, 00:00:03, Serial0/1/0

[120/1] via 158.75.9.38, 00:00:06, Serial0/1/1

R* 0.0.0.0/0 [120/1] via 158.75.9.38, 00:00:06, Serial0/1/1

running config of R3:

Building configuration...

Current configuration : 1328 bytes

!

version 15.4

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname Pargi_R2

!

no ip cef

no ipv6 cef

!

no ip domain-lookup

!

spanning-tree mode pvst

!

interface GigabitEthernet0/0/0

no ip address

duplex auto

speed auto

shutdown

!

interface GigabitEthernet0/0/1

no ip address

duplex auto

speed auto

!

interface GigabitEthernet0/0/1.1

encapsulation dot1Q 1 native

ip address 158.75.8.221 255.255.255.192

!

interface GigabitEthernet0/0/1.256

description default gateway of vlanZ

encapsulation dot1Q 256

ip address 158.75.8.129 255.255.255.192

!

interface GigabitEthernet0/0/1.313

description default gatway of vlanY

encapsulation dot1Q 313

ip address 158.75.8.1 255.255.255.128

!

interface Serial0/1/0

ip address 158.75.9.34 255.255.255.252

clock rate 2000000

!

interface Serial0/1/1

ip address 158.75.9.41 255.255.255.252

clock rate 2000000

!

interface Serial0/2/0

no ip address

clock rate 2000000

shutdown

!

interface Serial0/2/1

no ip address

clock rate 2000000

shutdown

!

interface Vlan1

no ip address

shutdown

!

router rip

version 2

network 158.75.0.0

no auto-summary

!

ip classless

!

ip flow-export version 9

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

end

IP Protocol of R3:

Routing Protocol is "rip"

Sending updates every 30 seconds, next due in 11 seconds

Invalid after 180 seconds, hold down 180, flushed after 240

Outgoing update filter list for all interfaces is not set

Incoming update filter list for all interfaces is not set

Redistributing: rip

Default version control: send version 2, receive 2

Interface Send Recv Triggered RIP Key-chain

Serial0/1/0 22

GigabitEthernet0/0/1.25622

GigabitEthernet0/0/1.31322

Serial0/1/1 22

GigabitEthernet0/0/1.122

Automatic network summarization is not in effect

Maximum path: 4

Routing for Networks:

158.75.0.0

Passive Interface(s):

Routing Information Sources:

Gateway Distance Last Update

158.75.9.42 120 00:00:26

158.75.9.33 120 00:00:26

Distance: (default is 120)

Routing table of R3:

Pargi_R2#sh ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP

i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area

* - candidate default, U - per-user static route, o - ODR

P - periodic downloaded static route

Gateway of last resort is 158.75.9.42 to network 0.0.0.0

158.75.0.0/16 is variably subnetted, 13 subnets, 6 masks

R 158.75.0.0/21 [120/1] via 158.75.9.33, 00:00:20, Serial0/1/0

C 158.75.8.0/25 is directly connected, GigabitEthernet0/0/1.313

L 158.75.8.1/32 is directly connected, GigabitEthernet0/0/1.313

C 158.75.8.128/26 is directly connected, GigabitEthernet0/0/1.256

L 158.75.8.129/32 is directly connected, GigabitEthernet0/0/1.256

C 158.75.8.192/26 is directly connected, GigabitEthernet0/0/1.1

L 158.75.8.221/32 is directly connected, GigabitEthernet0/0/1.1

R 158.75.9.0/27 [120/1] via 158.75.9.42, 00:00:12, Serial0/1/1

C 158.75.9.32/30 is directly connected, Serial0/1/0

L 158.75.9.34/32 is directly connected, Serial0/1/0

R 158.75.9.36/30 [120/1] via 158.75.9.33, 00:00:20, Serial0/1/0

[120/1] via 158.75.9.42, 00:00:12, Serial0/1/1

C 158.75.9.40/30 is directly connected, Serial0/1/1

L 158.75.9.41/32 is directly connected, Serial0/1/1

R* 0.0.0.0/0 [120/1] via 158.75.9.42, 00:00:12, Serial0/1/1topology

balaji.bandi · ‎03-18-2025

Router 0 can ping other interfaces of Router 3 except for the interface belonging in vlan1 (158.75.8.221) and the switch (158.75.8.220) and vise-versa in case of router3

Can we have Router1 configuration also, along with showing IP route information? I need to look at what the routing looks like. I see that the default route points to R1, as per the information. Post R3 connected switch config.

On R3 -

are you able to ping R0 interfaces and Switch IP addresses behind R0?

From R0, can you traceroute to R3 and Switch the IP address and post information?

BB

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View solution in original post

Giuseppe Larosa · ‎03-18-2025

Hello @rehnumarahmat ,

given your network topology routers are connected to each other using serial interfaces only so it is not correct to say that they share a VLAN.

Ignore everything related to this subnet because it is not really able to talk with other site. The giga port connects to local switch only.

Apart from this your setup is likely correct.

Hope to help

Giuseppe

balaji.bandi · ‎03-18-2025

Router 0 can ping other interfaces of Router 3 except for the interface belonging in vlan1 (158.75.8.221) and the switch (158.75.8.220) and vise-versa in case of router3

Can we have Router1 configuration also, along with showing IP route information? I need to look at what the routing looks like. I see that the default route points to R1, as per the information. Post R3 connected switch config.

On R3 -

are you able to ping R0 interfaces and Switch IP addresses behind R0?

From R0, can you traceroute to R3 and Switch the IP address and post information?

BB

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

How to Ask The Cisco Community for Help

rehnumarahmat · ‎03-19-2025

Hey, thank you for looking into this. I figured out the problem. The issue
was having both of the routers within the same vlan 1 range (whereas vlan1
range was supposed to be subnetted). Since they both belonged to the same
subnet, both of them advertised the same network on rip which resulted in
the discrepancy.
After i subnetted kodad router to be in 158.75.8.192/27 and pargi to be in
158.75.8.224/27 range, it worked.