Route to DHCP interace

[Mohd Khairul Nizam]

I have 2600 router.

int FastEthernett 0/0 retrieve IP from DHCP.

How can internal IP from VLAN 10,20,30 access Internet through Int FastEthernet 0/0

i try ip route to FastEthernet 0/0 but can't internet

Below is the config,

interface FastEthernet0/0
 ip address dhcp hostname DHCP
 duplex auto
 speed auto
!
interface FastEthernet0/1
 no ip address
 duplex auto
 speed auto
!
interface FastEthernet0/1.1
 description VLAN10
 encapsulation dot1Q 10
 ip address 192.168.10.254 255.255.255.0
!
interface FastEthernet0/1.2
 description VLAN 20
 encapsulation dot1Q 20
 ip address 192.168.20.254 255.255.255.0
!
interface FastEthernet0/1.3
 description VLAN 30
 encapsulation dot1Q 30
 ip address 192.168.30.254 255.255.255.0
!
!
ip classless
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0

[Julien JEGOU]

Hello,

What is connected on F0/0 ? Can you send us information about your interface F0/0 (show interface f0/0)?

Thanks

[Mohd Khairul Nizam]

below is the fa0/0

Cisco#sh int fa0/0
FastEthernet0/0 is up, line protocol is up
  Hardware is AmdFE, address is 000f.2360.4dc0 (bia 000f.2360.4dc0)
  Internet address is 172.28.7.158/16
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, 100BaseTX/FX
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:07, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 3000 bits/sec, 5 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     1016 packets input, 84709 bytes
     Received 851 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog
     0 input packets with dribble condition detected
     36 packets output, 4227 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     29 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

[Julien JEGOU]

Can you ping this IP address 172.28.7.158 with clients behind VLAN's ? Can you ping the device behind F0/0 from your cisco device?

[Mohd Khairul Nizam]

vlan client able to ping up to Fa0/0. (172.28.7.158)  & vice versa.

[Julien JEGOU]

Can you ping device behind F0/0 from your cisco device? what is behind this interface ?

[Mohd Khairul Nizam]

behind Fa0/0 is a face plate (network port) connecting to my office local LAN.

let say if i plug my notebook to the face plate, my nb will get dhcp and i can browse internet.

[Jon Marshall]

The device your router gets an IP from needs -

1) routes back to your router for your LAN subnets

2) it needs to NAT for those subnets

However if this is just a cable modem type device it may not support the above.

You can try doing the above but if it's not possible then just add this configuration to your router -

int fa0/0
ip nat outside

int fa0/1.1
ip nat inside

int fa0/1.2
ip nat inside

int fa0/1.3
ip nat inside

access-list 101 permit ip 192.168.10.0 0.0.0.255 any
access-list 101 permit ip 192.168.20.0 0.0.0.255 any
access-list 101 permit ip 192.168.30.0 0.0.0.255 any

ip nat inside source list 101 interface fa0/0 overload

Jon