2911 router will not get IP address from ISP

[willie01968]

I have been looking and as of yet found an answer to my problem.  I am hopeful that someone will see something that I don't and help me get my 2911 on line and working as expected.  I am currently running a 1921 router and its working flawlessly.  I am wanting to upgrade. I have configured the 2911 the same way I did the 1921.  The 1921 gets the ip address from the ISP no problem. The 2911 will not.  Doing some testing I hooked my 2911 up to my Netgear and it gets an IP address from it via DHCP.  I am going to post my settings and results below.  any help is appreciated.

1921

interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
ip address 192.168.2.1 255.255.255.0
ip helper-address 192.168.2.2
ip helper-address 192.168.2.1
ip nat inside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address dhcp
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/0/0
no ip address
!
interface GigabitEthernet0/0/1
no ip address
!
interface GigabitEthernet0/0/2
no ip address
!
interface GigabitEthernet0/0/3
no ip address
!
interface Vlan1
no ip address
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip dns server
ip nat inside source list 1 interface GigabitEthernet0/1 overload
ip route 0.0.0.0 0.0.0.0 138.43.190.1
!
!
!
access-list 1 permit any
!

show ip int brief

LR-404-Cat#sho ip int bri
Interface IP-Address OK? Method Status Protocol
Embedded-Service-Engine0/0 unassigned YES NVRAM administratively down down
GigabitEthernet0/0 192.168.2.1 YES NVRAM up up
GigabitEthernet0/1 138.43.xxx.xxx YES DHCP up up
GigabitEthernet0/0/0 unassigned YES unset down down
GigabitEthernet0/0/1 unassigned YES unset down down
GigabitEthernet0/0/2 unassigned YES unset down down
GigabitEthernet0/0/3 unassigned YES unset down down
NVI0 192.168.2.1 YES unset up up
Vlan1 unassigned YES unset down down
LR-404-Cat#

Shows the ip address from the internet provider and I can connect the internet.

now the 2911 with the ISP coming in on port G 0/1

404catz#sho ip int bri
Interface IP-Address OK? Method Status Protocol
Embedded-Service-Engine0/0 unassigned YES unset administratively down down
GigabitEthernet0/0 192.168.2.1 YES manual up up
GigabitEthernet0/1 unassigned YES DHCP up up
GigabitEthernet0/2 unassigned YES unset administratively down down
NVI0 192.168.2.1 YES unset up up

Configuration of the 2911

interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
ip address 192.168.2.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address dhcp
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/2
no ip address
shutdown
duplex auto
speed auto
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip nat inside source list 1 interface GigabitEthernet0/1 overload
ip route 0.0.0.0 0.0.0.0 138.43.190.1
!
!
!
access-list 1 permit any
!

Now if I hook up my Netgear to G0/1 I get an IP via DHCP

404catz#sho Ip int bri
Interface IP-Address OK? Method Status Protocol
Embedded-Service-Engine0/0 unassigned YES unset administratively down down
GigabitEthernet0/0 192.168.2.1 YES manual up up
GigabitEthernet0/1 10.0.0.10 YES DHCP up up
GigabitEthernet0/2 unassigned YES unset administratively down down
NVI0 192.168.2.1 YES unset up up

both routers the 1921 and 2911 are cofigured the same as far as I can tell.  I would appreciate some guidance on this.

thanks

[Richard Burts]

This is an interesting issue. My first suggestion would be that after you connect the 2911 to the ISP device that you power cycle the ISP device.

If there is still a problem my second suggestion would be to run debug for dhcp, make the connection, and post any debug output.

[paul driver]

Hello

---

@willie01968 wrote:

I am currently running a 1921 router and its working flawlessly.  I am wanting to upgrade. I have configured the 2911 the same way I did the 1921.  The 1921 gets the ip address from the ISP no problem. The 2911 will not. 

---

Its possible the ISP modem has tied down connectivity by allowing only the registered mac-access from the1921 router, so to test if this is the case. Assign the 2911 rtrs wan interface the same mac-address as the "older" 1921 wan interface

Additionally suggest to change your default static route
no ip route 0.0.0.0 0.0.0.0 138.43.190.1
ip route 0.0.0.0 0.0.0.0 gig0/1 dhcp

[willie01968]

I will attempt to debug dhcp. 

[MHM Cisco World]

friend the ISP use client-id to assign the IP to router, 
the issue is in ISP side not yours, 
check the cleint-id the ISP use for DHCP pool or server.

[Joseph W. Doherty · Accepted solution]

As other posters have described, often an ISP device will "latch" on to something about the device connecting to it.

If it's something like your interface's MAC, the two typical solutions are those suggested by @Richard Burts, power cycle the ISP device (if you can) or as suggested by @paul driver set your replacement device's interface MAC to be the same as the former device.

@MHM Cisco World suggests something else under the control of your ISP, which might be the case.  I.e. if you cannot, obtain a resolution using Rick's or Paul's suggestions, contact your ISP.

[willie01968]

I will contact my ISP Monday to find out what they are doing. I will ask about the pool that I am assigned or ask for a static. I will also do a DHCP debug to see what is comes up with.   Thanks for the assistance. 

[Georg Pauwen]

Hello,

a NAT access list that allows 'any' can cause issues. In addition, try and switch the interfaces (use Gig0/0 as the outside and Gig0/1 as the inside). So the confg looks like below:

interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
ip address dhcp
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address 192.168.2.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/2
no ip address
shutdown
duplex auto
speed auto
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip nat inside source list 1 interface GigabitEthernet0/0 overload
ip route 0.0.0.0 0.0.0.0 GigabitEthernet 0/0
!
access-list 1 permit 192.168.2.0 0.0.0.255
!