IP Changes Problems

[JH24]

I have just changed our IP addressing in our company over to the following.

172.16.0.0 255.255.252.0

I have put all the servers on 172.16.0.0
I have put all the Users workstations on 172.16.1.0
I have put firewalls and the like on 172.16.2.0

Between all these ranges i am able to ping everything.
Users can log into exchange and also applications on file servers and also open spreadsheets and the like on file servers though mapped network drives.

However after a while, whether they are using the open spreadsheet or application or have just left it idle they become disconnected from their outlook, spreadsheet etc.
I am still able to ping from their terminals to the server where the spreadsheet resides or the exchange server.

All users that connect to citrix servers on the 172.16.0.0 network from remote offices are fine and never crash out of applications or email.

I have taken some PC from our local LAN and have put them on the 172.16.1.0 range with the servers and their browsing is now a lot quicker and they do not become disconnected.

I am using a 255.255.252.0 subnet mask for everything on our local lan.
Like i said i can ping everything in the range but loose connectivity from the 172.16.1.0 to 172.16.0.0 but anything on 172.16.0.0 talking through to 172.16.0.254 are fine.

They are connected via Cisco 2950 switches and it is all pure LAN involved and no WAN.

There is no IP conflicts, also some terminals are using static IP, others DHCP, some terminals are Windows XP,others Windows 98.

Does anyone have any ideas?? as this is a major headache.

Thanks

 

[thedaver]

You have an IP overlap because of your mask.

Using 255.255.252.0 implies that you are using an extra bit from the hosts side of the IP at the expense of the network bits.

However, you seem to have a Class C (255.255.255.0) model in place with your networks of
172.16.0.0, ...1.0, and ...2.0

I think you actually DO HAVE IP conflicts because you have bad networks define here.

Change your netmask to 255.255.255.0 and add additional subnets if you have more than 250+ devices in a subnet.


Surfinbox.com Business Internet Services - National Dialup, DSL, T-1 and more.

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[JH24]

well the range i thought i should be able to use using a /22 subnet is
172.16.0.0 - 172.16.3.254 with the broadcast being 172.16.3.255

Surely i should be able to use all these IP's within the range i have specified above?
If i put a PC with an ip address of 172.16.2.40 on the network it can ping 172.16.0.5 with no problems at all.

I have not had any warning of ip conflicts either, not in any of the event views of any pc's or servers.
Also when the mapping is lost i am able to ping again.

Thanks

 

[thedaver]

I have to guess that you have a 255.255.255.0 netmask accidentally embedded in some router or in some hosts. I agree that your netmask and explained net segment should work.

Are the switches smart? are they programmed? Perhaps your problem is a switch or router that doesn't agree with your network plan.

Any Gateway definitions that don't match up?

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http://www.surfinbox.com/business/