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New Member

Cannot Ping RIP Routed IP

Hi All,

I have 3 routers within Boson Sim. PIR1, PIR2 and PIR3. Serial 0/0 on PIR1 has an IP 195.10.1.2/30 and PIR2 serial 0/0 195.10.1.3/30. PIR2 also has an IP 195.10.1.5/25 on the fastethernet 0/0 and PIR3 has an IP 195.10.1.6/25. All have been configured for RIP ver2. I added network 195.10.1.0 on all 3. The only connection that won't ping is between PIR1 and PIR2. What have I missed? Cheers.

coolboarderguy

1 ACCEPTED SOLUTION

Accepted Solutions
New Member

Re: Cannot Ping RIP Routed IP

Th ip add scheme you were using were overlapping each other.If your using /25 then the range is from 195.10.1.0-195.10.1.127. So, the other serial wont take the same interface.

Plan your ip add acheme in follg way:-

PIR1-195.10.1.129/30

PIR2-195.10.1.130/30

PIR2-195.10.1.1/25

PIR3-195.10.1.2/25

HTH.

Cheers,

Nikhil E.

9 REPLIES
Hall of Fame Super Bronze

Re: Cannot Ping RIP Routed IP

195.10.1.3/30 is the broadcast address for subnet 195.10.1.0/30.

The allowed host addresses for that subnet are 195.10.1.1/30 and 195.10.1.2/30

New Member

Re: Cannot Ping RIP Routed IP

DOH!! Ok, when setting serial 0/0 on PIR2 to 195.10.1.2/30 it says it overlaps with fastethernet 0/0 195.10.1.0. Cheers.

coolboarderguy

New Member

Re: Cannot Ping RIP Routed IP

Hi All,

obviously I'm doing something fundamentally wrong here? Cheers.

Gateway of last resort is not set

195.10.1.0/25 is subnetted, 1 subnets

C 195.10.1.0 is directly connected, FastEthernet0/0

coolboarerguy

Hall of Fame Super Silver

Re: Cannot Ping RIP Routed IP

Yes something is fundamentally wrong here. A basic concept of IP addressing and subnetting is that the same subnet should not exist in more than 1 place in the network. But you have taken the same /24 (class C) network and created serial link (/30) subnets and LAN (/25) subnets.

"PIR2 also has an IP 195.10.1.5/25 on the fastethernet 0/0 and PIR3 has an IP 195.10.1.6/25"

This puts the same /25 subnet on 2 different routers and the LAN subnet is using the same address space as the serial links.

My suggestion is to start over and plan a more effective addressing scheme.

HTH

Rick

New Member

Re: Cannot Ping RIP Routed IP

Th ip add scheme you were using were overlapping each other.If your using /25 then the range is from 195.10.1.0-195.10.1.127. So, the other serial wont take the same interface.

Plan your ip add acheme in follg way:-

PIR1-195.10.1.129/30

PIR2-195.10.1.130/30

PIR2-195.10.1.1/25

PIR3-195.10.1.2/25

HTH.

Cheers,

Nikhil E.

New Member

Re: Cannot Ping RIP Routed IP

Hi All,

ok, what's being said here, is, you can define larger subnet ranges and then break it down into smaller ones, IP/25 and then IP/30, but not IP/30 and then IP/25, yes? Cheers.

coolboardeguy

New Member

Re: Cannot Ping RIP Routed IP

Yes your absolutely right. Always go from high to low i.e. high no of users to low.This the best practice.

HTH.

Cheers,

Nikhil

Hall of Fame Super Silver

Re: Cannot Ping RIP Routed IP

Nikhil

There is a serious problem in your suggestion. You suggest this:

PIR2-195.10.1.1/25

PIR3-195.10.1.2/25

but this means that the same subnet will exist in 2 different places. Both of those addresses describe a subnet which starts at 195.10.1.1 and goes through 195.10.1.127. It is a problem if you try to put the same subnet on 2 different routers. If you want at least 2 LAN subnets and some serial subnets to all come out of a /24 (class C) address space then the LAN subnets can not be larger than /26 (instead of /25). With /25 there are only 2 subnets in the address space. With /26 you can have 4 subnets.

HTH

Rick

New Member

Re: Cannot Ping RIP Routed IP

Rick,

I think u hv taken me in wrong way.I'll elaborate it for you.

PIR1-195.10.1.0/25-PIR2-195.10.1.128/30-PIR3

Cheers,

Nikhil E.

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