Static IP and dynamic IP on the same router??

[Fozzie Bear]

I am trying to configure my network to the best effect but although I have a reasonable knowledge of networks port forwarding and TCP/IP etc I would like some advice on a proposed setup.
The configuration of my two ADSL circuits to date is as follows:-


First ADSL - Enta adsl circuit with dynamic WAN ip attached to a 3 com router with NAT enabled and DHCP enabled for the LAN which has a private address range. This is my main network with up to 10Pcs laptops and servers attached to the LAN and used for e-mail web access etc.

Second ADSL - Enta adsl circuit for backup purposes and external access with a block of 8 static IP addresses xxx.xxx.xxx.136-144. This circuit is connected to a D-Link DSL-G604T router with NAT currently disabled.
One IP address is assigned to the router WAN port (xxx.xxx.xxx.137), the second to the router itself (xxx.xxx.xxx.138), leaving xxx.xxx.xxx.139 to 143 as usable IP addresses as the first and last of the block 136 and 144 are not useable.
This adsl is for hosting a web server, ftp server and now a Windows Home Server which will probably replace both the former. I also want to use it for backup should the first adsl go down. My file server and Windows Home server are both dual homed with one nic assigned one of the usable static IP addresses and the second NIC configured for DHCP so that it picks up a private IP address from the 3Com router.This configuration allows direct access from the LAN and an internet facing IP. The lan is gigabit enabled with gigabit NICS and 16 port gigabit switch so that I can stream dvds and large files around the local network. What I would like to know is if it is possible to have both static routes and dynamic routes configured on the same router (D-Link DSL-G604T) ? For example can I assign a static IP address to the internet facing nic of the WHS but have the remaining IP addresses 140-143 delivered by DHCP. The reason for doing this is to change ADSL gateways should one broadband go down we would only have to disconnect from one wireless SSID (on the 3Com) and connect to the SSID on the other(D-Link network), without having to reconfigure the PC/Laptop with a static IP.

I assume that I would have to reconfigure NAT on the D-Link router so that I can enable DHCP on the D-Link LAN?

The question is how do I deal with the static IP allocation? Do I just open all the ports? Do I port forward the relevant ports ie ftp, https, RDP etc to the client(s) with the fixed IPs.

Alternatively should I just put the Static IP client(s) in the DMZ of the router (assuming this can be done on the G406T)?

This may seem a lot of work to share out a handful of IP addresses but I need something that is easy for my wife to change gateways but also allows the use of the static addresses to allow remote access and my web server to be available.
If I am expecting too much from the G406T I have a Linksys wrt54g cable router which I could connect to the G406T but I think I would run out of IP addresses???

Any help or advice on this would be appreciated.
regards Fozzie

[YeOldeStonecat]

I gotta sketch this down to get a better look at it...have to take off, not really any time for the computer tonight.

Have you considered multi-WAN routers, such as the Linksys/Cisco RV0 series? Or DLink has a model or two of multi WAN routers.

www.peplink.com is another.

For failover/redundancy...having both connections from the same ISP sorta throws away the theory. 9/10 times if broadband is down..the ISPs other links will be the same, it's usually widespread in your local node. Redundancy is best done having different ISPs across your WAN links.

You can IP map your additional public IP addresses to internal resources. Example...your two broadband modems uplink into a switch. Also uplinked into this switch..is your WAN interfaces of your two routers (or one router if you use a multi-WAN). Nothing else into this switch.

[Fozzie Bear]

For failover/redundancy...having both connections from the same ISP sorta throws away the theory. 9/10 times if broadband is down..the ISPs other links will be the same, it's usually widespread in your local node. Redundancy is best done having different ISPs across your WAN links.
.

Yes ideally you are absolutely correct. However here in the UK the failures tend to be between the site and the local exchange. Because I am situated at the extremes (over 5Km from the exchange) of ADSL I regularly get one link go down whilst the other is still available.
Its an annoyance for me that I cannot get e-mail or download files but my wife works from home and it stops her in her tracks if she cannot access the company portal.

I could sketch out my current arrangement and what I would like to achieve but not sure if you can upload attachments to this forum?

I like the look of the peplink router but can't find them for sale over here. Have to look at the Linksys or Dlink options.
Fozzie

[YeOldeStonecat]

Ahh.

What are your interests in building a *nix router distro like PFSense?
With having multiple routers...I'm not coming up with a smooth way to have auto failover if one link drops.
You can host files here under premium membership, else..for freebies...use one of the free image hosting sites.

[Fozzie Bear]

Thanks YeOldeStonecat,
That really looks interesting and I did at one time have a Smoothwall firewall on an old PC but to be honest I think it is getting too complicated. I am not overly worried about automatic failover.

What I would ideally like to achieve is a wireless connection to each of the ADSL circuits so that we can disconnect from one and connect to the other should one circuit go down. The only thing really stopping me at the moment is that the second ADSL with the D-Link G604T router has a defective wireless but even if it were working the fact that it is set up as No Nat means any client has to have one of the free static IP address. This means reconfiguring the wireless adapter IP settings every time you switch over. Being a corporate Laptop the company dont like me playing with network settings :nope:.

If there was a simple way to set up a static route to my Home Server and DHCP on the same router so all you have to do is switch SSID then that would be great.

Could you perhaps suggest an alternative wireless router that has these capabilities if the D-link is limited?

Fozzie