IP migration

[naveen_yummy]

hi guys,

In my company i am configured 15 VLAN. in that one is management VLAN and the remaining 14 used for each dept.

so that in managemet VLAN all servers and routers are configured.

currently we are using 192.168.X.X range.

right now i am going to migrate into 10.50.X.X range

so that all the dept we lan are configured with 10.50 range. but i dont want to change the IP range of management VLAN. it has to be in 192.168.X.X range only

if i did like that i have to assaign the secondary IP address to all the servers and switches.then only the Dept VLAN can access the management VLAN.

it is difficult to me. is there is any other way to access the servers without assainging the secondary IP.

thanks in advance.

[Mahesh Gohil]

Hi Naveen,

Seems to be good approach to avoid any service outage...but also think about split-horizon when using approach of

secondary ip address.

From cisco:-----If an interface is configured with secondary IP addresses and split horizon is enabled, updates might not be sourced by every secondary address. One routing update is sourced per network number unless split horizon is disabled.

To enable or disable split horizon, use one of the following commands in interface configuration mode:

Command 
Purpose 
ip split-horizon 
Enable split horizon. 
no ip split-horizon 
Disable split horizon. 

please look at below link

http://www.cisco.com/en/US/docs/ios/12_0/np1/configuration/guide/1crip.html#wp4813

Regards

Mahesh

[naveen_yummy]

hi mashel,

Thanks for your information.

But in my network i am not using the frame relay network or X.25 network.

My problem is,

All servers in the management VLAN is  192.168.X.X series. For migraton purpose i gave the seconday address for the management VLAN is 10.X.X.X

and i take one departmen VLAN.

for ex. Financial VLAN:Before migration - 192.168.X.X is the primary IP

                                  After Migration  - 10.X.X.X is the primary IP

After i migrated the finanical VLAN clients cant able to access the servers.

For that only i need solution. I think for this split horizon is not a problem.

[Mahesh Gohil · Accepted solution]

Hi Naveen,

So at time of migration you wish your servers (in 192...range) to talk to 10. (dept vlan) and 192. (mgmt vlan) at a time, and later

once everything is stable you will remove 10. (secondary) from management right..

if so it seems good to go with secondary address for servers and management interface. But split horizon is enabled by default for most of the

encapsulation,,so there might be chance that your servers with secondary ip (10.secondary ip) will not able to talk to dept.vlan (10.primary ip)

this is the reason i want you to keep in mind that if primary>>secondary ip is not reachable it could be problem of split horizon enabled. In that

case you have to disable it manually on interface.

i hope this is helpful at time of migration

Regards

Mahesh

[naveen_yummy]

hi magesh,

thanks for your reply's.... i will disable the split horizon and check the migration.....