Solved: Re: Ip route - Page 2

lucad7846 · ‎08-04-2022

Hi everyone

I am building a simple network for one of my assessments.

I would like to get the pc's to be able to communicate with the servers SydSVR and INTERNET on the remote networks.

I have tried adding a static route on SYD-R1 through its s0/0/1 interface. I tried 2 different routes which I have now deleted as they did not work. The routes where as follows:

0.0.0.0 0.0.0.0 s0/0/1 didn't work

192.168.206.0 255.255.255.0 s/0/0/1 (this network being one of the networks SM-PC's belong to - didn't work either)

If I ping from a pc's to the SYD-SVR1 I get a "destination unreachable message" from the default gateway PER-R1.

Attached is my PKT file. Passwords for all routers and switched is the usual, console is cisco and privilege exec is class.

I am not sure how to proceed from here. Any help would be much appreciated.

Cheers

Martin L · ‎08-04-2022

Yes but some Pings will Loop in your original file after adding configs shared above; this means there is error - usually a typo like wrong IP or interface id (hint: ping server to server will fail /check ip route statements)

10.0.0.0/30 is forgotten or unknown but not breaking per say (shouldn't said breaking). With static routing, all routers need to know all networks and those must be manually added. you could use a summary static routes and default routes in some places.

Of course, dynamic routing should be used. Try RIPv2, then EIGRP, and OSPF.

Regards, ML
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lucad7846 · ‎08-04-2022

Hi.

No ip routes

are configured in my original file.

The routes I have originally tried didn't work as stated in my original post. So I have deleted them before posting the file.

When you say ping will loop is that a good or a bad thing? I'm sorry I'm new to networking and certain things are still not 100% clear.

I have attached the configuration that I have applied. It was provided by my teacher for the assessment. SYD-R1 needed to have some Lo interfaces configured. Lo1 Lo2 and Lo3. Could this be the issue?

Attached is the table.

Many thanks for your help

Martin L · ‎08-04-2022

Loops are always bad thing; you are right, I double check there were

No ip routes

are configured in my original file. It had to be mine typo. So, Once you add other static routes, you should be able to ping OK. (compare to my file if u wish)

Note the error is Server IP of 192.x.x.x does not match connected router IP of 190.x.x.x - hence, upon mention "a typo."

Loopbacks are not an issue unless same IP is set up somewhere else.

Regards, ML
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lucad7846 · ‎08-04-2022

Hi thanks so much for your support. I'm still a bit confused. You said the error is Server IP of 192.x.x.x does not match connected router 190.x.x.x I'm not sure what that means?

Would you please be able to provide an example of a route that would work so that I can add it and try to understand a bit better? I'm so very sorry to bother you. I'm just trying to learn and this stuff can be very confusing at first.

Many thanks in advance

Martin L · ‎08-04-2022

There is a mistake, Table has Syd-R1 IP of G0/0 is 190.15.200.1 connecting to SYD Server IP of 192.168.101.50 over direct connection. Well, that's not going to work since 2 IPs must share the same subnet in order to communicate over direct link. Those 2 IPs are on different networks; So, either IP of Syd-R1 G0/0 should be 192.168.101.1 OR Syd -server should have IP of 190.15.200.2 , and not 192.168.101.50 as listed in the table.

You may want to clarify IP table with your instructor

Regards, ML
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lucad7846 · ‎08-04-2022

Hi

I see what you mean now. Thanks so very much for your patient and support. I am going to clarify this with my teacher. If I change one of the two IP's, would this work then?

Also, I tried the PKT file you shared and if I ping from any pc's to SYD-R1's g0/0 interface, I get the following reply "Reply from 10.0.0.1: Destination host unreachable"

Just out of curiosity as I am trying to learn, this would not work with RIPv2 either given the two directly connected interfaces are on different subnets? Am I guessing right?

Many thanks

Thanks so much in advance.

Martin L · ‎08-04-2022

Right, it will not work with RIP or any protocol or static route configuration. For any 2 devices on same link to talk to each others, they must be on same subnet, aka network, aka share link. Gig0.0 network is not advertised, no routes are set up. Ping will fail. You can fix it after correcting IP either on router or server. Remember ping is 2 way communication, so you need route to and from destination Or 2 routes. Tools to use are

 ping, trace, show ip route, show ip cef x.x.x.x

Regards, ML
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lucad7846 · ‎08-04-2022

Hi

So I spoke to my teacher and he agreed I can change the ip address of the server so that it is on the same subnet of SYD-R1.

I have now changed the ip of SYD-SVR, I have configured RIPv2 and everything works like a charm.

I still have one little problem though. The assessment requires all the routes to be advertised between routers aside from the 209.165.200.0 which is the network between SYD-R1 and ISP. So given this scenario, would I still need a static route for the pc's to be able to reach ISP and INTERNET? If that is the case, I am really not sure how to achieve this given my previous failed attempt to add a static route.

I have added the following static route on

PER-R1 - ip route 209.165.200.16 255.255.255.240 s0/0/0 -

you won't see this route in my PKT file on PER-R1 because it didn't work and I have deleted it. I did ping from one of the pc's and I was getting a "Reply from 10.0.0.1: Destination host unreachable".

Attached is my modified PKT file as well as requirements. I have highlighted the bit I am trying to solve.

If you could have a look for me that would be much appreciated.

Cheers

Martin L · ‎08-04-2022

Yes, this is because it is how it works normally in the real world. ISP knows about your Public IP or range and advertise it to other ISPs via BGP. But, there there is no dynamic routing between your company edge router (Syd) and ISP unless you are bigger business and can run BGP. Normally, you will need a default route on your edge router pointing towards ISP. Your Sydney router will do NAT/PAT as it mentioned in a doc. NAT/PAT translates private to public IP so that all internal devices can reach the Internet. But I think NAT is later in the course.

For now, you can add static route to 209.165.200.16/28 or static default one

aka ip route 0.0.0.0 0.0.0.0 next hop.

Also, ISP needs static default route for now. ( without NAT/PAT)

In total, I see 3 static route statements are needed to have full connectivity, even server to server. Or 2 if you follow requirement of a default route being sent to Perl via RIP (as mentioned in a doc).

Regards, ML
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lucad7846 · ‎08-04-2022

Hi thanks so much for the info.

It still doesn't work - I tried to mirror your PKT file Prototype1 configuration but still unable to ping from PC's to ISP and INTERNET. I can ping SYD-SVR from the PC's.

I even tried to advertise the route 209.165.200.0 via RIPv2 but I am still getting destination host unreachable from 10.0.0.1

On what router should I add the static routes you suggested? I am so very sorry I am very confused now. I have been working on this for the last week.

Many thanks in advance

Martin L · ‎08-05-2022

see my attach file; do pings from scenario 0 and then check configs

lucad7846 · ‎08-05-2022

Hi first I want to extend a big thank you for your help. I really appreciate your support.

I tried to ping from one of the pc's to INTERNET and it succeed now!

Just as a clarification, to achieve connectivity to the ISP you added a static route to both SYD-R1 and ISP? Or just one of the 2 router?

I am going to check your configuration, compare it to mine and try to understand where the differences are.

Thank so very much!

Martin L · ‎08-05-2022

Your edge router (one connected to ISP) will have default route (ip route 0/0 via ISP) and will do NAT/PAT. This edge router may also inform others about its default route via dynamic way with protocols. This is where RIP, EIGRP, OSPF could carry default route in their protocol updates instead of you doing /adding static routes to all your internal routers. Otherwise, you must tell your internal routers how to reach the edge router who "has the Internet" or "the way out"

ISP may or may not use static routes; it depends on ISP and its partners. ISP will not (or should not) use static route to advertise your public IP. Usually static routes in ISP are temporary solution or back up, or summary routes. The Internet runs on BGP and ISP usually advertise your Public IP via BGP. I would say Your Public IP can be reach because it is advertised by BGP but not because ISP static routes.

Regards, ML
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lucad7846 · ‎08-05-2022

Thanks ever so much for the detailed explanation. I am still a bit confused, but it's all slowly starting to make sense now.

Cheers

Martin L · ‎08-05-2022

Here are my summary rules:

2 IPs (2 devices) being on the same link (directly connected) MUST be on the same subnet/network in order to share info (like routing updates) and able to communicate, aka pings are ok

Router knows about its directly connected networks; he does not need any help. However, a network or destination that is 1 hop away needs to be entered into routing table manually (static route) or from routing protocol (dynamically). Use show ip route to see if your destination is reachable; Use trace IP to figure out how far can you reach destination and if it fails, where exactly failure occurs.

Default route (ip route 0/0 via x) should be used on edge or gateway and stub routers; Edge/gateway router is one that connects to ISP (aka its gateway to your Internet); while stub router is a router on the edge of your network with one way out; aka traffic leaving router must go via same link out.

Using interface as next hop in static route is OK but only in case of serial p2p links. Next hop IP is preferred over interface in all static routing. IP address must be used for all Ethernet links even Ethernet p2p links.

Regards, ML
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