CISCO 871W cannot ping external router interface

[jprophet64]

Good morning everyone,

I hope someone here could assist me with the situation I am facing, I am a network administrator who has been assigned the task of adding a secondary router to a redundant backup third party provided internet circuit. This router will serve two-fold firstly it will serve out dhcp addresses through a dhcp pool and secondly it will accomodate 2 Unifi AP access points. I'll show my config below but the end result is I cannot ping the outside router interface that the ISP has provided which ultimately should allow me to get on the internet.  My config is below:

CLTCHIEF2#show run
Building configuration...

Current configuration : 1934 bytes
!
! Last configuration change at 17:52:47 UTC Sun Mar 3 2002
!
version 15.1
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname CLTCHIEF2
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$fMm.$fVzzs3q6pnSM6avr03Nho1
enable password 7 12211D0E081115
!
no aaa new-model
!
!
dot11 syslog
ip source-route
ip dhcp excluded-address 172.16.102.1 172.16.102.99
ip dhcp excluded-address 172.16.102.151 172.16.102.254
!
ip dhcp pool CLT2WIRELESS
   network 172.16.102.0 255.255.255.0
   default-router 172.16.102.1
   domain-name INTERNAL.COM
   lease 7
!
!
ip cef
no ip domain lookup
!
!
!
!
!
!
!
!
!
!
bridge irb
!
!
!
interface FastEthernet0
!
interface FastEthernet1
 shutdown
!
interface FastEthernet2
!
interface FastEthernet3
!
interface FastEthernet4
 description WAN INTERFACE
 ip address 50.58.80.82 255.255.255.252
 ip nat outside
 ip virtual-reassembly
 duplex auto
 speed auto
!
interface Dot11Radio0
 no ip address
 shutdown
 speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0
 54.0
 station-role root
!
interface Vlan1
 description VLAN WIRED AND WIRELESS
 no ip address
 no ip redirects
 bridge-group 1
!
interface BVI1
 description VIRTUAL BONDED INTERFACE
 ip address 172.16.102.2 255.255.255.0
 no ip redirects
 no ip unreachables
 ip nat inside
 ip virtual-reassembly max-reassemblies 1024
 ip tcp adjust-mss 1360
 load-interval 30
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
ip nat inside source list 150 interface FastEthernet4 overload
ip route 0.0.0.0 0.0.0.0 172.16.102.1
ip route 0.0.0.0 0.0.0.0 50.58.80.81
!
access-list 150 remark NAT TRANSLATIONS
access-list 150 permit ip 172.16.102.0 0.0.0.255 any
!
!
!
snmp-server community public RO
!
control-plane
!
!
line con 0
 no modem enable
line aux 0
line vty 0 4
 password 7 07173955541300
 login
 transport input all
!
end

Does this config look right?

Thank-you.

[jprophet64]

ok so connected to the serial interace hyperterminal only I tried the following:

ping .81.......no joy

ping 82 .......100% success

8.8.8.8 ........no joy.

[Jon Marshall]

I thought you could ping the ISP address from the router ?

If you can't then the client connection won't work.

So did you run the ping on the router ?

If so check the arp table output again.

Jon

[Jon Marshall]

On the router can you -

"clear ip nat translations *"

then from the laptop try to ping the ISP address and post the output of -

"sh ip nat translations"

Jon

[jprophet64]

clear ip nat translations do i need to input that from config mode?

Its not taking for some reason.
 

[Jon Marshall]

No, it's just done from enable mode and you need a "*" at the end of the command.

You also run "sh ip nat translations" from enable mode as well.

Jon

[jprophet64]

ok so that command did finally take using

clear ip nat translation *

show ip nat translation does nothing it just goes to the next line

I can ping .82 the isp from the laptop it is successfull

[Jon Marshall]

The ISP is .81 not .82.

If the "sh ip nat translations" shows nothing I suspect you may still have connectivity issues.

Can you ping .81 from the router.

Before you do that can you "clear ip arp" and then try.

Jon

[jprophet64]

ok  the command clear ip arp is not complete until a valid address is entered would that be the .81 I am attaching a pic as to the output of show ip arp I did notice one of the hw addresses says incomplete

that probably an issue.

[Jon Marshall]

That's the issue ie. your router cannot get the mac address of the ISP router so you have no connectivity.

Which is confusing because a while back you posted a "sh ip arp" that did have an entry for the ISP router.

Did you change anything ?

Does "sh ip int br" show fa4 as up/up ?

Jon

[jprophet64]

yeah the fa4 interface3 is indeed up/up .

<<<<< did you change anything? >>>>>

Not that I am aware of with the exception of following procedures do you need to see a current config? It should be the same I would imagine.

[Jon Marshall]

If the configuration is the same as the last one you posted then no need to see it.

That configuration should work but obviously if you don't have connectivity to the ISP device nothing will.

You need to check the cabling etc.

Are you connecting directly to the ISP device or via a switch ?

If it's direct and fa4 is up/up then something really isn't right.

Jon

[jprophet64]

You guys are terrific! By the way I started a praise thread and it disappeared so it might gotten posted but the problems are all resolved. I unplugged the cable connected to fa4 and reconnected to the laptop and did another "show ip arp" and the router grabbed a mac address.

Thank-you so much both off you and all participants with the learning experience that was attained here and based on this I intend on completing my CCNA certification training.

May God bless you both!

John

[Jon Marshall]

John

I unplugged the cable connected to fa4 and reconnected to the laptop and did another "show ip arp" and the router grabbed a mac address

Not sure I follow this, do you mean you just unplugged the cable and then plugged it back in again and it worked ? 

Anyway glad you got it working.

Jon

[Richard Burts]

John

This has been an interesting discussion. I, like Jon, am glad that our suggestions helped you fix the issues and that it is now working.

Good luck as you work on your CCNA certification. These forums and the ones in the Cisco Learning Network are good resources to aid in your studies.

HTH

Rick

[jprophet64]

Rick,

Your continued persistence has been terrific, we might have solved this a little sooner iff I had been onsite with the equipment and sorry for the inconsistencies in the middle there. It feels good to know that there are individuals just as yourself and Jon that take the time to help with problems that are real world issues.

Again,

Thank-you so much and hope to converse with you again soon..

John