ā04-19-2021 09:37 AM - edited ā04-19-2021 12:36 PM
Hello guys,
I'm still new here so, I apologize in advance if I posted the question incorrectly.
I'm trying to create a network that consists of 2 buildings. Each building has 3 floors and each floor has its own local network. Below is the IP table for the local networks (Network addresses):
Building 1:
Production floor - 128.0.0.0/20
Testing floor - 128.0.16.0/21
Quality control floor - 128.0.24.0/22
Building 2:
Design floor - 128.0.28.0/23
Management floor - 128.0.30.0/24
Safety floor - 128.0.31.0/26
For each floor, I have a couple of end device connected to a switch and a router connected to the switch. So for each building I have 3 routers that connect all the local areas together. I then added 2 routers to connect both buildings together.
My plan is that I want to create a 3 layer network with redundancies but I only created 2 layers to test the connections. I would like to use RIP as the routing protocol. The issue I am having is that I can ping the devices in the local network but I can't ping devices from different networks. When ever I try to do so in the command prompt, I get a message that says "Destination host unreachable". I set all routers to work with RIP and I added all the networks in each router but I still can't figure out what's the issue. I have attached 2 pictures, 1 showing an overview of the whole current network and another showing a close up of one of the local networks.
Your help is much appreciated.
Update: I have made some changes based on the suggestions I have received so far. All the devices in one building are pinging each other successfully but the second building isn't working.
I have also attached the latest packet tracer project (Protocol used RIPv2)
Solved! Go to Solution.
ā04-19-2021 02:04 PM
Hello Boda,
to make the two buildings to communicate you need a common IP subnet between the two routers on the top that interconnect with a serial line and to run RIPv2 over it.
RIPv1 does not support your network topology because you have used different subnet masks taken from major network 128.0.0.0
But RIPv2 should work .
If you use major network 128.1.0.0 for inter router links you need to disable auto summary under RIPv2
Hope to help
Giuseppe
ā04-19-2021 09:42 AM
You need also show configuration example : Try use RIPv2
But i always suggest to use OSPF or EIGRP for the requirement, if this is Lab for testing. you can do as many as testing you want with different IGP
ā04-19-2021 09:47 AM
I am really sorry I don't think I fully understand what you mean. I used the router GUI to add the networks for RIP and this is exactly what is inside each router:
128.0.0.0 (the local areas network)
128.1.0.0 (The rest are connections between each router)
128.2.0.0
128.3.0.0
128.4.0.0
128.5.0.0
128.11.0.0
128.12.0.0
Is that right?
ā04-19-2021 02:04 PM
Hello Boda,
to make the two buildings to communicate you need a common IP subnet between the two routers on the top that interconnect with a serial line and to run RIPv2 over it.
RIPv1 does not support your network topology because you have used different subnet masks taken from major network 128.0.0.0
But RIPv2 should work .
If you use major network 128.1.0.0 for inter router links you need to disable auto summary under RIPv2
Hope to help
Giuseppe
ā04-19-2021 02:50 PM
Dear Giuseppe,
Thank you so much for your explanation, it helped a lot. The whole network works perfect now. This is my first time hearing about auto summary and I will definitely need to read more about it.
Much appreciated,
Boda
ā04-20-2021 06:32 AM
If I remember correctly, Cisco's auto summary is related to classful addressing. When on, it aggregates "real" subnets up into their class's address block. When off, "real" subnets are classless networks (with routing protocols that support classless addressing).
Classful addressing isn't much used much any more, but you can enounter a few issues were it can still arise, as in the auto summary config statement.
BTW, if you follow the rules for classful addressing, RIP would work fine for you too, but routing with classful "real" subnets has its own special rules.
ā04-20-2021 10:20 AM
Hello Boda,
auto-summary is triggered by a change of major network when sending updates out an interface in a different major network like 128.1.0.0 is when compared with 128.0.0.0, the auto-summary feature causes the router to send the classful 128.0.0.0/16 instead of the known subnets.
in your case you have a partitioned major network 128.0.0.0 as some subnets are in the first building and some are in the second building and the inter router link is in 128.1.0.0 major network.
Disabling auto-summary allows each router to send the known subnets of 128.0.0.0/16 to each other
Hope to help
Giuseppe
ā04-23-2021 02:58 AM
Dear Giuseppe,
That makes sense now. Thank you so much, you have helped me a lot. Your efforts are much appreciated.
Regards,
Boda
ā04-19-2021 09:53 AM
Possibly you might be bumping into the issue that RIP is a classful routing protocol. (NB: 128.x.x.x is a class B address block, i.e. /16.)
RIPv2 (suggested by Balaji) supports classless although it still embeds some classful features.
OSPF or EIGRP (as also suggested by Balaji) better support classless than RIPv2.
ā04-19-2021 10:41 AM
I tired RIPv2 like you guys said and I am successfully pinging some devices in the same building, however, I can't seem to ping devices from the other building. I'm trying to research about OSPF and EIGRP. But in the mean time, do you have any idea why this might be happening?
ā04-19-2021 11:28 AM
Hello,
this looks like a Packet Tracer project, if that is the case, post the zipped project (.pkt) file...
ā04-19-2021 11:44 AM
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide