Static Route issue

[Ahmed Malik]

ok so i have made a network and the main Router R1 is the router that is acting as a Dhcp. now i have attached another router R2 to R1 via serial cable. the devices that are directly connected to R1 get their ips from R1 but the devices that are connected to R2 arent getting their ips from R1. i have entered sttic routes to both routers also did the ip-helper address command on interface Fa0/0 on router R2 but dont know whats wrong with this problem.

I am attaching the Packet tracrer file so ppl can see it for yourself.

Looking fwd to hear from you.

Thanks,

Regards,

Ahmed

[Vaibhava Varma]

Hi Ahmed

Is the DHCP Server IP identified in "helper-addres" command reachable from R2 F0/0 Interface IP as Source ?

From my understanding there might be a probable reachability issue between the LAN Pool on R2 and the R1 DHCP Server IP.

Can you please share the config on R1 and R2 ?

Regards

Varma

[Ahmed Malik]

ok here is the config for both routers.

For R1 :-

hostname R1

ip dhcp excluded-address 172.16.10.1 172.16.10.10

ip dhcp excluded-address 192.168.5.1 192.168.5.10

!

ip dhcp pool Admin

network 172.16.10.0 255.255.255.0

default-router 172.16.10.1

ip dhcp pool Testing

network 192.168.5.0 255.255.255.0

default-router 192.168.5.1

!

!

!

!

!

!

!

ip domain-name lammle.com

ip name-server 172.16.10.2

!

!

!

!

!

!

interface FastEthernet0/0

description Dhcp for clients

ip address 172.16.10.1 255.255.255.0

duplex auto

speed auto

!

interface FastEthernet0/1

description Testing Link

ip address 192.168.5.1 255.255.255.0

duplex auto

speed auto

!

interface Serial1/0

ip address 172.10.5.1 255.255.255.252

!

interface Serial1/1

no ip address

!

interface Serial1/2

no ip address

!

interface Serial1/3

no ip address

!

interface Serial1/4

no ip address

!

interface Serial1/5

no ip address

!

interface Serial1/6

no ip address

!

interface Serial1/7

no ip address

!

interface Vlan1

no ip address

shutdown

!

ip classless

!

!

!

!

!

!

!

line con 0

line vty 0 4

login

!

!

!

end

and here is the config for R2 :-

hostname R2

ip domain-name lammle.com

ip name-server 172.16.10.2

!

!

!

!

!

!

interface FastEthernet0/0

ip address 10.5.3.1 255.255.255.0

ip helper-address 172.16.10.1

duplex auto

speed auto

!

interface FastEthernet0/1

no ip address

duplex auto

speed auto

shutdown

!

interface Serial1/0

ip address 172.10.5.2 255.255.255.252

clock rate 1000000

!

interface Serial1/1

no ip address

shutdown

!

interface Serial1/2

no ip address

shutdown

!

interface Serial1/3

no ip address

shutdown

!

interface Vlan1

no ip address

shutdown

!

ip classless

ip route 172.16.10.0 255.255.255.0 172.10.5.1 150

ip route 192.168.5.0 255.255.255.0 172.10.5.1 150

!

!

!

!

!

!

!

line con 0

line vty 0 4

login

!

!

!

end

looking fwd to hear frm you

Regards,

Ahmed

[johnlloyd_13 · Accepted solution]

hi ahmed,

kindly add the following on your R1 and do an ipconfig/renew on your PC behind R2.

ip dhcp excluded-address 10.5.3.1 10.5.3.10

ip dhcp pool

network 10.5.3.0 255.255.255.0

default-router 10.5.3.1

ip route 10.5.3.0 255.255.255.0 172.10.5.2

[Ahmed Malik]

hi john,

there r 2 PCs behind R2 so ipconfig/renew (what does it do) for both of them?

and do i have to describe another dhcp pool for PCs that are behind R2 or they can gets ips from dhcp pool on interface fa0/1 of R1?

another question is that for each interface on a router i have to setup a new dhcp pool ?

regards,

Ahmed

[johnlloyd_13 · Accepted solution]

hi ahmed,

if your PCs behind R2 doesn't automatically get any IP address, then perform an ipconfig/renew.

you need to create a DHCP pool for each network created for your LAN. using the ip helper-address command under the LAN interface or SVI helps re-direct the DHCP discover broadcast coming from a different subnet/VLAN from where the DHCP server is located, towards the router acting as the DHCP server.

[Ahmed Malik]

hi john,

i still have a confusion and its that when we r defining the dhcp pool for the 2 Pcs behind R2 we created a dhcp pool on router R1 and in that dhcp pool commands we mentioned that the default router is 10.5.3.1, whereas the serial interface of router R1 that is towards R2 has an ip address of 172.10.5.1 dont we have to mention this as the default router??

And can u explain this static route

ip route 10.5.3.0 255.255.255.0 172.10.5.2

i mean i am not getting this static route command at all.

help me out here please

Regards,

Ahmed

[johnlloyd_13 · Accepted solution]

hi ahmed,

we set the default router to 10.5.3.1 for your 10.5.3.0/24 since this will be your PC's default gateway (first hop) when communicating to other subnet. the IP address 172.10.5.1 is on a different subnet and can't be used as your default gateway for your 10.5.3.0/24.

you need the static route in order for R1 to know how to get to the 10.5.3.0/24 network.