my network simulation

I have used boson simulation software i created 2 routers and 2 switches and two pc's the pc's are in different subnets after configuring the serial dce dte and bringing up the interfaces and assigning them ip addresses and adding a couple of routes i ended up being able to route between the two pc's on different subnets. I used the 2501 and the 2514. Does that mean if i had a real 2501 and 2514 and the 1900 switches i should beable to do the same thing in a real enviorment ?

Apart from the fact that you would only need one router to route between two subnets, the above scenario should work in real life as well.

yeah in theory you could route between as many subnets as the router had interfaces with a single router right ?

That's generally true unless you consider the "Router-on-a-stick" option.

can you explain to me this router on a stick ?

Router on a stick is refering to utilising VLAN Trunking to a router to then route between the VLAN and send the traffic back to the switch on the correct VLAN.

If you have for example 4 VLAN's configured on your switch and you create a VLAN TRunk to the router, the router is then able to route between the VLAN's using the 802.1q/ISL trunking to encapsulate the VLAN traffic.

Basically, the VLAN2 traffic goes to the router, the router will then de-encapsulate the VLAN information, see where its being sent to (i.e. a different VLAN down the trunck), it will then re-encapsulate the packet with the new VLAN (say VLAN4) and then send it down the trunk to the switch, its then tagged for the correct VLAN