Can't ping interfaces on a router

[HookedJoi]

Hello,

I'm a complete beginner, so this might be a simple issue.

I cannot ping interface G0/1 and Loopback 0 on Router3 (and Router4 at all) from PC0 (blue cable between PC0 and Router4 is Console).

Below is my network made in Packet Tracer:

Router3 can ping all interfaces visible on the diagram above, same as Router4 (except PC0).

Initially, I wanted to have one big subnet 192.168.1.0/24 but while trying to configure it on different interfaces it said that IPs where overlapping. Similiar to this issue:

https://community.cisco.com/t5/routing/ip-overlapping-with-gigabit-ethernet-0-0-help/td-p/3050192

I think the problem might still be with subnetting but I don't know what I could do.

Output of a few commands:

ROUTER3

Router3#show ip interface brief

Interface IP-Address OK? Method Status Protocol

GigabitEthernet0/0 192.168.1.2 YES manual up up

GigabitEthernet0/1 192.168.1.9 YES manual up up

GigabitEthernet0/2 unassigned YES unset administratively down down

Loopback0 172.116.1.20 YES manual up up

Vlan1 unassigned YES unset administratively down down

======

Router3#show cdp neighbors

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone

Device ID Local Intrfce Holdtme Capability Platform Port ID

Router4 Gig 0/1 134 R C2900 Gig 0/1

======

Router3#show 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 not set




172.16.0.0/24 is subnetted, 1 subnets

S 172.16.1.0/24 [1/0] via 192.168.1.10

172.116.0.0/16 is variably subnetted, 2 subnets, 2 masks

C 172.116.1.0/24 is directly connected, Loopback0

L 172.116.1.20/32 is directly connected, Loopback0

192.168.1.0/24 is variably subnetted, 4 subnets, 2 masks

C 192.168.1.0/29 is directly connected, GigabitEthernet0/0

L 192.168.1.2/32 is directly connected, GigabitEthernet0/0

C 192.168.1.8/29 is directly connected, GigabitEthernet0/1

L 192.168.1.9/32 is directly connected, GigabitEthernet0/1




ROUTER4

Router4#show ip interface brief

Interface IP-Address OK? Method Status Protocol

GigabitEthernet0/0 unassigned YES unset administratively down down

GigabitEthernet0/1 192.168.1.10 YES manual up up

GigabitEthernet0/2 unassigned YES unset administratively down down

Loopback0 172.16.1.1 YES manual up up

Vlan1 unassigned YES unset administratively down down

======

Router4#show cdp neighbors

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone

Device ID Local Intrfce Holdtme Capability Platform Port ID

Router3 Gig 0/1 176 R C2900 Gig 0/1

======

Router4#show 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 not set




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

C 172.16.1.0/24 is directly connected, Loopback0

L 172.16.1.1/32 is directly connected, Loopback0

172.116.0.0/24 is subnetted, 1 subnets

S 172.116.1.0/24 [1/0] via 192.168.1.9

192.168.1.0/24 is variably subnetted, 3 subnets, 2 masks

S 192.168.1.0/29 [1/0] via 192.168.1.9

C 192.168.1.8/29 is directly connected, GigabitEthernet0/1

L 192.168.1.10/32 is directly connected, GigabitEthernet0/1

Thanks in advance

[Georg Pauwen]

Hello,

post your zipped Packet Tracer project (.pkt) file...

[balaji.bandi]

Since the routing not aware rest of the network, PC0 does not know how to reach other IP address and back

since you are not running any IGP

quick and dirty fix is adding static route :

Router 3:  (add below)

ip route 0.0.0.0 0.0.0.0 192.168.1.10

Router 4:  (add below)

ip route 0.0.0.0 0.0.0.0 192.168.1.9

and test from PC including IP and loopback should work.

[Richard Burts · Accepted solution]

Based on the symptoms my guess is that PC0 does not have a correct default gateway.

[HookedJoi]

Hello,

to be honest I completely forgot about the gateway for PC0. Once I set it as G0/0 interface it started working as it should. 

Thank you all for help!

[balaji.bandi]

nice @Richard Burts  catch on the PC0.

If the PC0 have default gateway 192.168.1.2 configured.

Does the Default gateway fix for the PC0 to  reach 192.168.1.10 ? and 172.16.1.1 also 172.161.1.20 ? 

with out adding any route ?

[Richard Burts]

You are welcome. Glad that my suggestion was helpful. Default gateway is a small but important part of the device config (and fairly easy to overlook). Thanks for telling us that now it is working as it should. Thank you for marking this question as solved. This will help other participants in the community to identify discussions which have helpful information. This community is an excellent place to ask questions and to learn about networking. I hope to see you continue to be active in the community.