subnet question

[carl_townshend]

hi all, can anyone answer this for me, If im using 192.168.1.253/30, can I still use the full 192.168.1.0/24 somewhere else ?

[vijayasankar]

Hi Carl,

It is not a correct design. Well you can use the other ips in that range, only if it falls in a different segment.

In this scenario 192.168.1.253 falls in the range of 192.168.1.0/24.

Hence you cannot an ip which falls in the subnet somewhere else. It is not Proper design.

HTH

-VJ

[o.hassairi]

your q is not clear, do you mean: can u route between the 2 subnets?

[carl_townshend]

Hi

I meant that if I use 192.168.1.253/30 and 192.168.1.254/30 for my wan links, can I still use the 192.168.1.0 network ?

[Anand Narayana]

Hi Carl,

if you use 192.168.1.253/30 & 192.168.1.254/30 you can use 192.168.1.0. if it is /30. if it is 192.168.1.0/24 , ip address 192.168.1.1/24 can reach 192.168.1.253 & 192.168.1.254. but tell me whether you wanted to keep 192.168.1.0/24 on the LAN interface & 192.168.1.253 & 254/30 in WAN interface?

[carl_townshend]

basically the 192.168.1.0 network points somewhere else, the wan links are in a seperate place, doesnt 192.168.1.253 and 254 fall within the 192.168.1.0/24 network though, my question really is, can I still use the whole /24 range ?

[vijayasankar]

Hi Carl,

As stated earlier, it is not a correct design.

-VJ

[ariazk]

hi,

you can use this range, you need to play with routing according to your scenario.

[carl_townshend]

so am i right in saying the /30 links are totally seperate to the /24 network ? or do they still fall within it ?

[Anand Narayana]

Hi Carl,

to make you more simple to understand, 192.168.1.0/24 pc's cannot ping 192.168.1.253/30 & 192.168.1.254/30. as it is considered as different network.

[carl_townshend]

thanks for that, so with them both being different networks, I can use more /30's in from the 192.168.1.0 network, and yet still use the whole /24 of that network ?

[ariazk]

you are the part of this /30 but router choose more specific route to route the packet.

[ilya.varlashkin]

You can, as long as 'ip classless' is enabled on your router _and_ /30 networks are advertised by some classless routing protocol (RIPv2, OSPF, EIGRP, but not classfull RIPv1 or IGRP) _and_ they're not summarized. Sometimes such situation is result of (auto)aggregation with discontigous subnets, will work but not necessarily a good thing and I'd try to avoid this whenever possible.