Use private ip address for 3550 switch

[chrish]

Hi, Can we use private ip addresses (192.168.1.1) for 3550 switches (to conserve ip addresses) and still access for configuration? We tested, but couldn't access, does there need to be further configuration in router or core switch to access the switch for configuration? Thanks, Chris.

[devang_etcom]

crish,

i think you are going to use that ip address for the management purpose...right...you can able to access it from your local lan but you are not allow to access it from the internet as private ip addresses are not allow in internet...

and can you tell me what is your exact requiremet...?

rate this post if it helps

regards

Devang

[chrish]

Hi Devang,

Yes, we are toying with the idea of using private ip for the management of the box, but at this point we can't access from our internal LAN, not necessarily from the Internet. We usually use Telnet session or web browser to access the switch to make a configuration change. It works when we configure the switch with a real ip address from our network, but doesn't seem to work using a private (fake) ip address. I was wondering if there was more to do to make this work internally. Thanks, Chris.

[devang_etcom]

so you have configure the vty line for telnet access and also configure the password ...

[chrish]

The switch is configured correctly and we were able to access when it was give a public ip address. When we replaced the public ip with a private ip we were no longer able to access the device. We were wondering if we needed to alter our core router or core switch to identify the private ip address of the switch. Thanks, Chris.

[vladrac-ccna]

Hello,

you need to make this IP reachable inside your network.

Is this IP routable inside your network?

Vlad

[devang_etcom]

yes first of all check it out its rechability...means that ip should be reachable from router or switch or host from which you are tryig to access...

as mension in your previous post, the real ip is reachable and by private it is not...

if you are able to access using realip then you must be able to access using private...may be the private ip is publish or reachable in your network...\

and for further help look at this link:http://www.cisco.com/en/US/products/hw/switches/ps646/products_configuration_guide_chapter09186a00801f0a45.html#1046352

hope this will help you

rate this post if it helps

regards

Devang

[chrish]

Hi Devang, Thank you for the link, but upon first glance this doesn't seem to answer my question. I will keep reviewing the doc to make sure and will rate if it helps. Thanks, Chris.

[chrish]

Hi Vlad, I thought they were, but upon second check, I don't see it designated in our core router. This is probably it, what would be the best way to make the private ip routable inside our network? Is there any handy documentation? Thanks, Chris.

[devang_etcom]

just publish that private ip address in your routing protocol ...

[chrish]

Hi Devang, Do you have a little more detailed description? Thanks, Chris.

[vladrac-ccna]

Hello,

you need to make this ip reachable. what is the routing protocol you are using?

you could use a static route to it too and then redistribute it inside your routing protocol.

Give us more details on the IPs and routing inside your network and we'll be glad to help.

this is quite simple and should not be a problem.

Vlad

[chrish]

We are using TCP/IP as the protocol. We have a 6509 core switch/rtr & the peripheral switches are connected to the core switch by fiber. The ip address is 192.168.7.x, but if this works we are planning on updating all of our other switches. We have 3 separate segments (vlans) with public ip addresses on our network, some how we will need to incorporate the other addresses. Thanks, Chris.

[Richard Burts]

Chris

I believe that there are two parts to what you need to do to make the switch reachable when it is configured with private IP address. First, as others have mentioned, you need to have an entry in the routing table for the private network. Depending on the routing protocol that you use you may be able to accomplish this by configuring a secondary address on the interface from your core switch. To do that would take something like this:

interface vlan

ip address 192.168.7.253 255.255.255.0 secondary

and then put a network statement into your routing protocol for the private network:

router eigrp 1

network 192.168.7.0

Another alternative would be to configure a static route to 192.168.7.0 and redistribute the static route into your routing protocol.

After you achieve getting an entry in the routing table for the private IP, then the second part is configure the default gateway on the switch to be able to get to your core switch. If you took the alternative of configuring a secondary address on the core switch then setting the default gateway on the switch is as easy as pointing the default gateway to the private secondary address on the core switch.

HTH

Rick

[chrish]

Hi Rick, This sounds like what we are looking for and makes sense. I appreciate your time in providing this answer. Thanks, Chris.