Subnets summarisation

[Bienvenu Ngala]

Hi Everyone,

This question may look stupid but its importance is vital to me as I am learning this technolgy my question is this:

I have configure 5 vlans on my L3 switch: - vlan 10 ip address 192.168.10.1  255.255.255.0

                                                                               - vlan 20 ip address 192.168.20.1  255.255.255.0

                                                                               - vlan 30 ip address 192.168.30.1  255.255.255.0

                                                                               - vlan 40 ip address 192.168.40.1  255.255.255.0

                                                                               - vlan 50 ip address 192.168.50.1  255.255.255.0

Now, what is the subnet summarisation of all these ip addresses or what is a unique ip address summarising all these subnets.

Best regards,

BEN

[Marvin Rhoads · Accepted solution]

A /19 equates to 32 Class C networks. Not enough. So you would need to summarize with a /18 (255.255.192.0) which includes 64 Class C's. The summarization would be:

     192.168.0.0 255.255.192.0

That includes addresses from 192.168.0.1 through 192.168.63.254 (not including the all zeros network number and all ones broadcast addresses).

[Bienvenu Ngala]

Hi Marvin,

That's correct my network Lab is up and running, Many thanks