06-24-2013 08:53 AM - edited 03-07-2019 02:03 PM
Hello all,
I have been doing some IP address planning and whould like the following:
10.24.X.0/24 for some networks
10.24.255.X/32 for the loopbacks of the gateway switch/routers
The networks will start from 10.24.0.0/24 so the first loopback would be 10.24.255.0/32. I did some GNS3 testing and all worked fine. Can I use this 0 (zero) on the last octet with no problem? Is there any case where this can create problems?
I intend to user EIGRP dynamic routing.
Thanks
06-24-2013 09:01 AM
Hi,
You can not use the network address for an interface. It has to be a host address
So for example you can assign 10.24.255.1/32 to the first router and 10.24.255.2/32 to the second router and so on.....
HTH
06-24-2013 09:37 AM
Hello,
I do not agree. You can use use it as any other only-one-host network (.1/32 .2/32 so on). IOS accepts the command
without problem. EIGRP is a classful protocol and it supports VLSM subnets. So, there are no issues to use it in
Loopback interfaces.
Anyway, Could you explain the Loopback address' purposes?
06-24-2013 02:46 PM
Hi Antonio,
I believe youmeant classless and not classful.
I'll use the loopback address to reach and manage the switch/routers as they'll have 2/3 L3 links to them. The loopbacks will also be advertised dynamically.
Sent from Cisco Technical Support iPad App
06-24-2013 11:10 PM
Hi Mario,
you are right I mean "classless routing protocol". I have used addresses .0 for example in a NAT pool (customers
used a .0 address to go to internet) without problem during 2 years. If you use it to management addresses
I think threre are no issues.
@sjuneay I think you mean "ip subnet-zero" command.
Regards
06-25-2013 11:13 AM
Hi Antonio,
Thanks for sharing this. It's always good to hear (read) from other's experience. I will actually implement it and hopefully won't get any problems since our devices are all very new.
Sjuneau,
The router is already running classless and allowind subnet-zero yes
06-24-2013 04:40 PM
Hi,
Can you use the command ip classless? This command works in a router to tell it that the subnets that you define do not follow the different classes of ip address. A class being x.0.0.0 for example 10.0.0.0, B class x.x.0.0, etc.
I did this on routers using eigrp.
HTH
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