One switch multi network

[dror000011]

Hey,

I have bought Cisco Switch ws-c4948-10ge and i want to install him in my data center.

I have from the ISP 2 diffrent networks

1. 37.19.125.xxx with subnet 255.255.255.224

2. 37.19.126.xxx with subnet 255.255.255.240

How i config the switch to work with diffrent networks?

Sorry for my bad english :/

Thank you.

[Joseph W. Doherty]

Depends how you intend to use those two networks, and how you're going to work with your two ISPs.

For example, it might be a simple as setting a VLAN for each subnet, and setting hosts on those subnets to use the provider's IP as their gateway IP.  In this example, the switch would be running as a L2 switch.

If you need to move traffic from those public networks to/from your internal networks, you may need to enable routing on your switch.  If your internal networks are using private addressing, you'll need NAT, and I don't recall the 4948 having that feature.

What you're asking is complicated enough you should consider retaining a network engineer to configure you device.

[dror000011]

Thank you for your answer.

this is public to public..

I have 2 blocks of addresses that i want to use..

My question is how i config it in my switch..

[Julio E. Moisa]

Hi

As Joseph mentioned the switches dont support NAT, can we know the reason to connect the ISP on this switch? or the main purpose?

[dror000011]

Hey,

I will explain

I have two outside ip rangs with diffrent subnets.

And i want connect the hosts direct to this network (without use internal network)

This is posible?

ISP (2 public networks) -> switch -> hosts (every host assign with public IP)

so i dont need NAT, right?

If so, how i do that?

Thank you!

[chintalamuniraju]

HI !

Can you please check this one i hope it will help you 

Thanks 

CRaju

[Julio E. Moisa]

Hi

Yes, that is possible but not recommended by security and it is not a scalable way to use the public IP addresses, a NAT should be used. But you can assign public IP address to your host:

The configuration should be:

1. 37.19.125.xxx with subnet 255.255.255.224

2. 37.19.126.xxx with subnet 255.255.255.240

Example:

SWITCH:

Vlan 125
name RANGE1

vlan 126
name RANGE2

vlan 777
name NATIVE-VLAN

Imagine you are going to use intervlan routing, the provider should configure subinterfaces on its router to communicate with the vlans, for example:

interface g1/1
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk native vlan 777
no shutdown

* If you are going to use a different native vlan than 1, the provider should configure it on their end as well.

Then you configure the switchport to be used for the hosts, on the hosts you should configure the IP address manually and use public DNS.

int g1/2
description HOST-VLAN125
switchport host
switchport access vlan 125
no shutdown

int g1/40
description HOST-VLAN126
switchport host
switchport access vlan 126
no shutdown

Imagine you are going to use intervlan routing, the provider should configure subinterfaces on its router to communicate with the vlans, for example:

ISP ROUTER

interface  g0/0
description TO-SWITCH4948
no shutdown

interface g0/0.125
description GATEWAY-VLAN125
encapsulation dot1q 125
ip add 37.19.125.1 255.255.255.0

interface g0/0.126
description GATEWAY-VLAN126
encapsulation dot1q 126
ip add 37.19.126.1 255.255.255.0

interface g0/0.777
description NATIVE-VLAN
encapsulation dot1q 777 native

But again, in my humble opinion a Router with NAT configuration should be the best solution for this scenario.

Please don't forget to rate the comment if it is useful.

:-)

[dror000011]

First - Thank you!!!

You right.. that not look the right way..

If i will put pFsense Fw/router before the switch and connect my own pfsense to the switch, this is better way?

if so, you can explain to me?

p.s. if you want i will ready to pay you.

You the best! Thank you!

[Julio E. Moisa]

Hi

That's correct a router connected to the switch will be a good design. No worries my friend, thank you but the payment is not needed. 

It will be pleasure to assist you. Just please let me investigate about that router brand.

:-)

[dror000011]

I have pfsense (FW) custom machine

And I have another problem, When I saved the config of the switch and when I restart the switch, I cant ping to switch but the config is saved. Becuse that I need connect serial cable every time and reconfig the switch :/

You know why?

[dror000011]

I have two range IPs from one ISP (public IPs).

And I want to Assign this address direct to hosts, I need do routing in my switch?

If so, how i do it?

[dror000011]

someone?