How can I setup config VLAN to ping?

[adamlee1811]

I want to ping from PC5 to R2 or PC6 but I can't. I have configured VLAN for PC(2,3,4,5,6,7).

So should I config NAT with R3 so that PC5 can ping to R2?

Help me. Thanks

[Jon Marshall]

Is SW1 routing for the vlans or is it R3 ? 

If it is R3 then you are running OSPF so R2 should know how to get back to PC5. 

Jon

[adamlee1811]

[Jon Marshall]

R3 does not have any OSPF routes. 

Are you meant to be running OSPF between the routers or are you looking to use NAT instead ? 

Jon

[adamlee1811]

I don't know why R3 doesn't have any OSPF routes. Here is my config 

R1(config)#router ospf  1

R1(config-router)#network 172.8.55.0  0.0.0.255  area 0

R2(config)#router ospf 1

R2(config-router)#network 172.8.55.0  0.0.0.255  area 0

R3(config)#router ospf 1

R3(config-router)# network 172.8.55.0  0.0.0.255  area 0

[Jon Marshall]

Is that a typo ie. you have repeated the same network 3 times. 

You should have network statements for the vlan subnets 172.10.55.0/24, 172.20.55.0/24, 172.30.55.0/24 but you also need to check the other routers because they don't seem to be advertising any routes to R3 either. 

You need to check each router and check your OSPF configuration. 

Jon

[adamlee1811]

Hi it is not i.o type. In my documentation the syntax is 

Router(config-router)#network A.B.C.D wildcard-mask {Area-ID}

So I don't know how to fix OSPF problem. As you can see, R3 has R2, R1 OSPF neighbors

[Jon Marshall]

I have just explained how to fix it. 

You need to add network statements for the other networks eg. on R3 - 

router ospf 1
network 172.8.55.0 0.0.0.255 area 0
network 172.10.55.0 0.0.0.255 area 0
network 172.20.55.0 0.0.0.255 area 0
network 172.30.55.0 0.0.0.255 area

and then you need to go to the other routers and do the same for the local subnets. 

This is assuming you want to advertise all the subnets via OSPF. 

Jon

[adamlee1811]

After config that, I can ping from PC to R2 but can't ping from PC to another router (Example PC2,3,4,5 to R1 or PC6,PC7 to R3) or ping from PC2 to PC6. What should I do

[Jon Marshall]

You need to check the routing tables of R1/R2 and R3 and make sure all routers know how to reach all the other subnets. 

It sounds like some of the routes are still not being advertised so you work you way through each router, do a "sh ip route" and make sure each router has routes to the remote subnets. 

If they do then come back and let us know. 

Jon

[adamlee1811]

OK

[adamlee1811]

That's my sh ip route. Is there any problem here?

[Jon Marshall]

Yes, the problem is you have the same subnets on R1 and R3 which won't work. 

Your routers are connected using the 172.8.55.0/24 subnet so you cannot then have the same subnet eg. 172.10.55.0/24 on two different routers ie. you cannot route to the same subnet. 

You need to use different subnets on one of the routers and readdress your PCs. 

Jon

[adamlee1811]

Thank, I fix that bug.

[Jon Marshall · Accepted solution]

What do the routing tables look like on R1 and R3 ie. do you have a route for 11.0.0.0/30 ?

If not you can configure OSPF on R2 to send a default route to R1 and R3 you can add this to R2's OSPF configuration - 

router ospf 1
default-information originate

Jon