Topic: two IP addresses on SME

[leondardo]

hi,

My ISP is oferring to give us two IP addresses. I'm connecting through ADSL using a regular modem to ethernet. I have one ethernet card connected with the DSL modem, and the other connected to the local network.

My question: is it possible to make use of the second IP address by adding a third network card to the SME box. How would this be accomplished if my DSL modem has only one RJ45 outlet?

Regards,

[Toady]

If it were me, I would not add the second network card...

You can just add a second IP address to the external card, I dont quite know how this would work with the wirewall though.


To add the second address the command is somthing like
ifconfig eth0:0 12.34.56.78 up

since eth0:0 wont be defined in the firewall setup, I think you might have problems getting traffic from outside

[Boris]

Unless you have use for the second IP (seperate server perhaps) you don't need it. Most small home networks use just single IP just fine. I have number of small business clients who get small subnets (5 usable IP) as a smallest possible for the business account and only use one IP for all their needs.
If you still decide to use second IP, you will need either hub/switch between DSL modem and two servers or different firewall, that can use alias for public NIC (IPCop, m0n0wall or similar)and no hub.
SME can be configure to use second IP, but this will take a lot of manual configuration and risk of misconfiguring (may couse major security holes). I wouldn't recomend to do this unless you are REALLY know how to do this. You would not be asking this question if you did on the first place.

[leondardo]

Actually, I want to use the second IP and put a DNS server on it. I thought I would use White Box Linux to configure a second DNS server and have it connected on the second IP address.

So, I understand that the connection will go from the DSL modem to the hub, and then two wires will go to two different servers. This configuration is fine with me.

Now, what about the first server running SME. Do I keep everything as normal? For now, the external card is configured to connect using PPPoE by providing a username and a password. It will obtain the static IP address automatically. Do I keep it as is? Or do I have to choose the option of "Static IP address" and have it entered there?

Thanks,

[Boris]

Ask your ISP about the details. Typically multiple IPs associated with static address assignment.

[hardijs]

look for 1to1 nat (sometime ago a script was generously made available.

though I would advise you to re consider your actual needs for the second ip #

One more thing is that one can edit masq templates
say adding a "/30" after $externalIp in the templates (as far as I remember) you can make all your address subnet to be served...

[Kevin]

m0n0wall may be a better solution for your firewall to do this

http://m0n0.ch/wall/

[Leonardo]

Thank you all for replying. I called my ISP for more details. They said that my modem does not support routing (Mainstreet Xpress 27020 - from Newbridge Networks  corp.). They advised that I should get a new modem that supports routing. They suggested a new Netopia 3300.

Anyone has ever heard of that brand before? Is it good?

Would there be any way to do the routing without the need to purchase the new suggested modem and router?

Thanks,

[Boris]

It was a generic suggestion that you need a router/firewall. SME does it as well. No need to buy a router.
Ask your ISP if IPs they going to give you plain static or required an authentication of some kind?

I typically trash junk DSL routers provided by ISP and replace then with simple external DSL modem (that you already have) and use SME or other boxes as router/firewall/server with it.

[Leonardo]

It needs authentication. I configure the gateway to connect using the PPPoE and provide a username and a password. I understood from the ISP that when my gateway sends the username and password information, it is assigned the same static IP address from their servers.

According to them, the second IP address should be configured in the router. I do not want to purchase a router if it is not necessary.

[Boris]

PPPoE (that you use now) connection may change if you switch to different plan. Ask your ISP how it will work with multiple IPs.