I have two cisco 3640 routers one for mumbai and other for delhi. We have registered IP of class 10.26.11.0 and using subnet mask of 255.255.255.128.
On serial link can we use the same network with diffrent subnet like 10.26.11.0 with mask of 255.255.255.252. Currently we are using 200.200.200.0 on serial link. At mumbai we have 10.26.12.0 with mask 255.255.255.0.