How can I get area A to talk to area B?

[maxintime]

Hi there,

I am using packet tracer and I have an issue with area A talking to area B or area B to area A

Cloud is configured to use modem4 to Ethernet6

Server has DHCP on and can talk to router and other PC in area A but not area B

Area A inside IP is: 192.168.1.1 and area B is 192.168.2.1

Area B needs to have a wireless router.

RIP works with two routers not one so I am unsure how this should work.

Any ideas?

[Enes Simnica]

hello G. first thing pleaseeee let the RIP die ahahahha funny (i wouuld use EIGRP or OSPF.....) and sounds like u're dealing with inter-area communication issues in Packet Tracer. Here are some key things to check. For OSPF to work between Area A and Area B, both must connect through Area 0 (the backbone). Ensure each router has an interface in its local area and in Area 0. Use show ip ospf neighbor to verify adjacencies and sh ip route to confirm OSPF routes are being learned.

For the DHCP server in Area A that can't reach Area B, make sure devices have the correct default gateway for example 192.168.1.1) and check that the router has proper routes between subnets. The wireless router in Area B should have a WAN IP from the 192.168.2.0 network and a different LAN subnet 192.168.3.0) to avoid conflicts.

If using RIP, ensure all routers along the path run RIP. If mixing RIP and OSPF, route redistribution will be required.

Soo just  confirm OSPF area configs, ping from the server to Area B’s router (192.168.2.1), and ensure interfaces are up. If the issue continues, sharing ur packet tracer topology would really help in spotting the problem.

hope it helps G

-Enes

[Enes Simnica]

and G when I say share the topology, I mean upload it as a ZIP file.....

[maxintime]

Thanks for the response.

Here is the PT file in a zip file

[Enes Simnica]

hey man, I took a quicklook at ur setup, and I think that dsl modem might be causing more trouble than it’s worth. Packet tracer’s modem is pretty limited, cause it doesn’t really act like a real world modem, and it can’t do routing or NAT properly. It’s just making things harder than they need to be. Instead, try swapping it out for a basic router (like a 2911) to act as your ISP. Give it an IP like 123.1.1.2/24 and set up a default route. That way, you’ve got full control over how traffic flows, and you won’t be fighting PT’s quirks.

If you’re trying to simulate internet access, you can either: Use the Cloud as a simple passthrough (no IPs needed) and assign public IPs to your routers or / just skip the Cloud entirely and connect your edge router straight to the ISP router.

just sayin that packet tracer is great for learning the basics, but it’s not cut out for realistic ISP setups. so if u want to dive deeper into things like BGP or real NAT, u’ll have better luck with GNS3 or EVE-NG. At the end of the day, the best way to figure this out is to tweak it urself. Mess around with the configs, simplify the design, and see what works. That’s how you’ll really learn....

-Enes

[maxintime]

You're suggesting that I cut the modem and replace it with router 2911 to act as the ISP (123.10.1.1) and directly connect it to the wireless router in area B with a default route to get everything to ping?

This needs to be done on both routers? next IP would be 192.168.1.1?

ip route 123.10.0.0 255.0.0.0 [next hop IP address]

I'm been trying for over a week trying to get this to work, this learning is not fun atm.

[Enes Simnica]

loool I feel u G. I’ll go through ur lab in detail later today when I’m free. We’ve got this, dw

-Enes

[maxintime]

That would be wonderful! I am keen to know how this is supposed to work, I did as you suggested and connected both routers to each other and at the serial interface and added 123,10.1.1 but no luck.

[Enes Simnica · Accepted solution]

hello @maxintime. Finally found 10 minutes for your lab man... after a really long week packed with a complex network migration project. But here it is, fully working and clean. So thats what i did:

1. Replaced the wireless router in area B, and why, cause it uses NAT by default and doesn’t support advanced routing or tunneling protocols (like GRE or VPN). It was replaced with a Cisco router that supports full static routing and tunneling features.

2. Added static routing between area a and b so both routers know how to reach each others lan networks (so u have routerA 192.168.1.1 and wan 123.1.1.1 and RouterB 192.168.2.1 and wan 123.1.1.2).

3. COnfigured a GRE Tunnel - to stimulate a VPN tunnel, between router a and router b (Tunnel IPs: 10.0.0.01 - 10.0.0.2), So now LAN traffic from area a to area b (and vice versa) is routed via Tunnel0 interfaces.

4. Dhcp setup on server and also added a new switch on area B so that each host has a switch to connect to....

Now the REason that i didnt use rip, is because RIP is  unnecessary here because we have only two routers and know the destination networks, thats why static routes are more efficient for ur situation.

also u can test it like this:

from laptop 0 (area B) ping 192.168.1.12 - - reaches server in Area A
from laptop 1 (area A) ping 192.168.2.10 - - reaches Laptop in Area B

from RouterA #show ip route - = Should show route to 192.168.2.0 via Tunnel0
and show interface tunnel0 -- Confirm tunnel status (up/up)

from routerB #sh ip route -- Should show route to 192.168.1.0 via Tunnel0
and #sh inter t0 -- again it confirms the tunnel status up up

so in general u have a basic BUT fully functional site to site setup between two lans over a stimulated internet (which in packet tracer is done by the CLOUD-PT device and DSL modem which they act as a LAYER 1/2 PASSTHROUGH, so thats all they can do on packet tracer....) check the toplogy on the zip file....

hope it helps G, and ping me if u have more questions....

-Enes

[maxintime]

You really want all in with this, thanks for the effort!

I have a few questions

How do I have a wireless router in area B?

Was there a way to make this work without VPNs or tunnels?

Can you provide the tunnel commands used to set up tunnel for others who might come across this?

[Enes Simnica]

Yes, this topology can absolutely function without VPNs or tunnels, I just wanted to make the setup a bit more interesting by adding a GRE tunnel.

As for the wireless router, feel free to add it to Area B if u’d like, but keep in mind it uses NAT by default, which can introduce some communication issues with routed networks (like masking internal IPs)....

For the GRE tunnel, here’s the configuration i used:

On RouterA:

interface Tunnel0
 ip address 10.0.0.1 255.255.255.252
 tunnel source GigabitEthernet0/1
 tunnel destination 123.1.1.2
 no shutdown

ip route 192.168.2.0 255.255.255.0 10.0.0.2

On RouterB:

interface Tunnel0
 ip address 10.0.0.2 255.255.255.252
 tunnel source GigabitEthernet0/0
 tunnel destination 123.1.1.1
 no shutdown

ip route 192.168.1.0 255.255.255.0 10.0.0.1

[maxintime]

it is interesting, I am curious to know how the setup would work without a tunnel?

WAN from router A to router B?

[Enes Simnica]

Without the GRE tunnel, the setup would still work the same in terms of connectivity, because we have static routes on both routers pointing to each other's LANs via their WAN IPs (123.1.1.1 and 123.1.1.2). As long as there's IP reachability and NAT isn't interfering, traffic will flow normally without the tunnel.

The GRE tunnel just adds a logical path whic is very very useful for simulating VPNs or making the network more realistic in certain scenarios. But functionally? Static routing handles it just fine.

try it, just remove the gre config.. easy....

[maxintime]

@Enes Simnica I've been looking more at the PT file you have attached and have understood the way it works from the details you have posted. I think my only question now is about configuring the wireless router so it can pass the packets to the network. Do you know how to remove NAT from it?

further more, thanks to your help I was able to work out what I did wrong when I tried the routing.

[Enes Simnica]

Hey @maxintime , glad to hear it helped and awesome that you figured out the routing part! 

As for the wireless router mann, unfortunately in Packet Tracer, the default wireless router (like the "Linksys" type) doesn't let u disable NAT or support advanced routing features. That's why I swapped it with a standard Cisco router, which gives u full control over routing, NAT, tunnels, etc.

So in short: u can't fully remove NAT on the built-in wireless router in PT, but u can simulate Wi-Fi by adding a wireless access point + a Cisco router if you still want wireless clients...

-Enes