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Error routing or NAT on Modem Cisco 1700

francois
Level 1
Level 1

Hello,

I have an old modem Cisco 1700 with ADSL as backup connection.

I have configured PPPoA, the sync is OK and connection is UP.

I get Wan IP et Gateway, (routes automatically added).

I have added NAT and routes but impossible to go out.

I try to ping an external IP but no response.

Can someone check my configuration ? Something wrong with NAT or routing ?

Thanks for you help...

FV

Building configuration...

!

version 12.2

service timestamps debug datetime msec

service timestamps log datetime msec

no service password-encryption

!

hostname cisco-modem

!

logging queue-limit 100

!

ip subnet-zero

!

ip dhcp excluded-address 10.10.110.1

!

ip audit notify log

ip audit po max-events 100

!

interface ATM0/0

no ip address

load-interval 30

no atm ilmi-keepalive

pvc 8/35

encapsulation aal5mux ppp dialer

pppoe-client dial-pool-number 1

!

dsl operating-mode auto

!

interface FastEthernet0/0

ip address 10.10.110.1 255.255.255.0

no ip proxy-arp

ip nat inside

speed auto

half-duplex

!

interface Dialer0

mtu 1492

ip address negotiated

ip nat outside

encapsulation ppp

ip route-cache flow

dialer pool 1

dialer-group 1

ppp authentication chap callin

ppp chap hostname ******

ppp chap password 0 ****

!

ip nat inside source list 1 interface Dialer0 overload

ip classless

ip route 0.0.0.0 0.0.0.0 Dialer0

ip route 192.168.110.0 255.255.255.0 10.10.110.254

ip http server

no ip http secure-server

!

access-list 1 permit 10.10.110.0 0.0.0.255

dialer-list 1 protocol ip permit

!

!

line con 0

logging synchronous

line aux 0

line vty 0 4

logging synchronous

login

!

no scheduler allocate

end

7 Replies 7

Jon Marshall
Hall of Fame
Hall of Fame

Nothing obviously wrong. Can you answer the following questions -

1) what IP address are you pinging from ie. a PC or laptop IP

2) from the device you are pinging from ca you ping the inside interface of the router ?

3) from the router can you ping something on the internet

Jon

Thanks for your reply.

I try to ping 8.8.8.8 (Dns google) or Wan IP address or the Gateway from the cisco.

No response from it.

FV

Francois

Just to clarify. So you are pinging from the router itself ? If so NAT is irrelevant, it sounds like there is an issue with your connectivity to your ISP.

Jon

Yes I am pinging from the modem Cisco I try to configure.

Do you know commands I can use to check the connectivity ?

Thanks

FV

I don't understand.  The config sems to be correct.

I have configured the ADSL connection on a basic linksys modem with the same configuration and it works perfectly on it... (I can ping the WAN IP, the Gateway, 8.8.8.8,...)

I have no idea what's wrong with the configuration of the cisco

Problem with routing ? NAT ?

Thank you


FV

if you cant ping the ip address of the dial0 interface that is really strange. 

Does it get an internet address with the command

show ip int brief

Yes I get my Wan IP but unable to ping... (see result below)

But I often get this message :

*Apr 27 20:34:41.878: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access5, changed state to down

*Apr 27 20:34:46.433: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access5, changed state to up

cisco-modem#show ip interface brief

Interface                  IP-Address      OK? Method Status                Protocol

FastEthernet0/0            10.10.110.1     YES manual up                    up

ATM0/0                     unassigned      YES manual up                    up

ATM0/0.1                   unassigned      YES unset  up                    up

Virtual-Access1            unassigned      YES unset  up                    up

Dialer0                    77.109.**.**    YES IPCP   up                    up

Virtual-Access2            unassigned      YES unset  up                    up

Virtual-Access3            unassigned      YES unset  down                  down

Virtual-Access4            unassigned      YES unset  down                  down

Virtual-Access5            unassigned      YES unset  up                    up

cisco-modem#ping 77.109.**.**

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 77.109.**.**, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

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