Can I safely add old DLink Router to network?

I run a 2 desktop computers plus one notebook system.
ADSL 8MB speed via ModemRouter D-Link 2542B (ADSL 2+,20 MB speed compliant).
Two desktops connect via Ethernet port only,while the notebook can randomly do that via wireless, if needed, via a D-Link DAP1160 G Access Point (also ADSL 2+, 20MB) which has a similar-only last digit changed- Gateway,but obviously changed IP.

All work fine,but

I would like to bring an extra security layer to only one of the two Ethernet connected computers by adding a second Router to the existing ModemRouter.

Instead of buying a new one I thought of using my old D-Link DI-604 Router ,which I used until 2 years ago ,which is only older and limited to a max of 8MB speed.

It has no ADSL+ or IPV6 capability,but I have disabled IPV6 in my Windows7 64 bit anyway.

Can I use this old model nonetheless-considering that my subscription is still an
8 MB one (with real speeds of 5-6 MB on average and 0,7 Mb upload) and that the
famous IPV6 is nowhere in sight?

Also,as my ModemRouter has a
192.168.1.x
line of Ips, so will just a change to a
192.168.2.x
be ok for the added D-Link DI-604 Router wire connected to the new ModemRouter D-Link 2542B ?

 

Cudni,thanks for your reply- I've given IP numbers to all computers and devices (AP DAP1160,mainly) and also disabled DHCP in modem-router at the moment.

By disabling DHCP i found I have a perfect connection from the very moment I turn it on, whereas having it working caused a series of 2-3 random brief disconnections in the first hour.

By 'dish out the adresses' I take it you mean the external adresses, aint it so?

Really there should be nothing difficult in setting up this second router,but what is of some theoretical concern to me is : will using that older router cause any 'strain' or in reality they're basically the same and nothing wrong should ensue?

As a matter of fact I used the old DLink 8MB router for some years and it was always perfect for a real speed of 5/6 MBs,now I dont think there could be any problems coupling it with a ADSL+ 20MB DLink (modem-router) brother which in reality keeps going at the same speed.

What you think Cudni?

 

Fine,then,I'll go on with it tomorrow-if able to sleep at least a few hours...
To you Cudni,and to all Wilders friends,a super New Year!

 

In brief: I now have added my second Router B (Dlink DI-604) to the previous network and connection is fine and all computers work ok, but,having made some modifications to the rule I'd like to know if this config is fine for keeping Router B computer1 COMPLETELY separate from
Modem-Router A (Dlink 2542B) computer2+notebook.

ModemRouter A settings:
192.168.1.1
255.255.255.0
DHCP Enabled
Range 0 to 255
OpenDNS in router

Router B WAN side:
Static IP 192.168.1.2
255.255.255.0
Gateway 192.168.1.1

Router B LAN side:
IP (router IP) 192.168.2.1
255.255.255.252
DHCP disabled
Pings from WAN enabled


Computer-Network Card-
IP 192.168.2.2
255.255.255.0
Gateway: 192.168.2.1



Computer1 behind routerB works perfectly well ,but i'm concerned on account of the difference in subnet mask btw RouterB LAN side and Network Card.....initially I just forgot to adjust the network card,but later i left it as it is since it works......although i suspect that ,being it the same subnet as modemrouter A, it might weaken the NAT?

Can any knowledgeable soul please spot any weakness, bearing in mind I didnt do that to enlarge,a switch would have done,but to increase security for just computer1-the one behind Router B?

PS- I forgot to add router B is wired to router A like this : WAN (Internet) to LAN1.