Unable to establishing link between two routers with different subnet

[kasulasaiganesh]

I have two ISR 4351 routers and I'm trying to  esatliblising connectivity between 2 routers with serial interface. Is it possible to connect with different subnets?

R1# serial 0/0/0 

ip address 192.168.1.1/24

encapsulation ppp

R2# serial 0/0/0

ip address 192.168.2.1/24

encapsulation ppp

[kasulasaiganesh]

Yes! I did same thing on R2 also

[Joseph W. Doherty]

Again (please), what's the actual default route statements?

[Joseph W. Doherty]

Oh, forgot to ask, have you tried it with same subnet interface IPs?

[kasulasaiganesh]

Yes I tried with same subnets it's working.

[balaji.bandi]

You mean disjoined subnet in p2p address ?

[balaji.bandi]

we have suggested some config, have you got chance to read and tried ?

[kasulasaiganesh]

It's working. But my question is it possible to connect with different subnets.

[paul driver · Accepted solution]

Hello
It is possible to do, You will need to ultise virtual-templates to accoplish it, try the following:

RTR1
int ser 0/0/0
ip address 192.168.1.1 255.255.255.0
enacp Fr
clock rate 64000
no keepalives
frame-relau map ip 192.168.2.1 121
frame-realy interface-dlci 121 ppp virtual-template 12

int virtual-template 12
ip address 192.168.1.1 255.255.255.0

RTR2
int ser 0/0/0
ip address 192.168.2.1 255.255.255.0
enacp Fr
no keepalives
frame-relau map ip 192.168.1.1 121
frame-realy interface-dlci 121 ppp virtual-template 21

int virtual-template 12
ip address 192.168.2.1 255.255.255.0

[kasulasaiganesh]

Thanks Paul  it's really great effort.  Now both routers are communicating.

But I'm not able to ping from PC1 to Router2. Please kindly look at that problem. 

RTR1 # interface FastEthernet0/0 ip address 172.16.1.1 255.255.255.0 duplex auto speed auto # interface Serial0/0 ip address 192.168.1.1 255.255.255.0 encapsulation frame-relay no keepalive clock rate 2000000 frame-relay map ip 192.168.2.1 121 frame-relay interface-dlci 121 ppp Virtual-Template12 # interface Virtual-Template12 ip address 192.168.1.1 255.255.255.0 # ip route 0.0.0.0 0.0.0.0 Serial0/0

RTR2 # interface FastEthernet0/0 ip address 172.16.2.1 255.255.255.0 duplex auto speed auto # interface Serial0/0 ip address 192.168.2.1 255.255.255.0 encapsulation frame-relay no keepalive clock rate 2000000 frame-relay map ip 192.168.1.1 121 frame-relay interface-dlci 121 ppp Virtual-Template12 # interface Virtual-Template12 ip address 192.168.2.1 255.255.255.0 # ip route 0.0.0.0 0.0.0.0 Serial0/0

Any additional routing  is required ?

[DaviRocK!]

post config ip and gateway of both pc and ip route of both router

[kasulasaiganesh]

R1# ip route 0.0.0.0 0.0.0.0 Serial0/0

R2# ip route 0.0.0.0 0.0.0.0 Serial0/0

PC1                                                                                                PC2

 

[Joseph W. Doherty]

That's likely because @paul driver's  (creative) approach would still require additional route statements.  For example, R2 wouldn't know where to send traffic for the 172.16.1.0/24 network.  (What I had suggested, using default routes on R1 and R2, which from @DaviRocK!'s testing works, may work, for your just posted topology.  [I'm assuming PC's have local router as gateway.])

[kasulasaiganesh]

@Joseph W. Doherty  I think we are missing some additional route statements. 

[Joseph W. Doherty]

---

@kasulasaiganesh wrote:

@Joseph W. Doherty  I think we are missing some additional route statements. 

---

Yes OR the "correct" route statements.

R1 and R2 "know" of all directly connected networks.

A default route, on both R1 and R2, directing all non-connected networks, to the other router, would solve the routing issue in your last posted topology.  BTW, this also would still be true if your R1<>R2 link shared the same network.

[kasulasaiganesh · Accepted solution]

@Joseph W. Doherty @paul driver @DaviRocK! 

It's working with static routes. Why? default route is not working. Anyway we got a solution finally. Thanks @paul driver @Joseph W. Doherty @DaviRocK! 

R1:-

R2:-

PC-1                                                                      PC-2