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Using 2611 Router to connect to internet Via cable modem

CSCO12165174
Level 1
Level 1

Hi guys,

I am with Virgin media and have a home lab (2611 routers, 3550 switches, 2950s etc) which i usually just use for testing things on and practicing.

Now I tried to connect it to the internet and got some weird things happening.

I got NAT and DHCP client all setup correctly on the router (or so  I think!) along with DNS settings but I still can't get Internet access.

My network is all setup right so that through using OSPF the router is the gateway (0.0.0.0 route) for all devices.

Doing a traceroute confirms this.

Yet I never get any further than the router?  I see IP nat translations ticking up as I send more requests but never get a webpage or a reply from any of the machines in my network.

HOWEVER...

The router itself does get some replies from Google.co.uk and bbc.co.uk but doesn't seem to want to give anything else on the "inside" a response?

Any help please guys it would be much appreciated.

Here is a dump of config:

version 12.4

service timestamps debug datetime msec

service timestamps log datetime msec

no service password-encryption

!

hostname R1

!

boot-start-marker

boot-end-marker

!

!

no aaa new-model

memory-size iomem 10

no network-clock-participate slot 1

no network-clock-participate wic 0

ip cef

!

!

!

!

ip name-server 194.168.4.100

ip name-server 194.168.8.100

ip auth-proxy max-nodata-conns 3

ip admission max-nodata-conns 3

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!        

!

!

!

!

interface FastEthernet0/0

ip address 10.10.10.1 255.255.255.0

ip nat inside

ip virtual-reassembly

duplex auto

speed auto

!

interface Serial0/0

no ip address

shutdown

!

interface FastEthernet0/1

ip address dhcp

ip nat outside

ip virtual-reassembly

duplex auto

speed auto

!

interface Serial0/1

no ip address

shutdown

!

interface Serial0/2

no ip address

shutdown

!

router ospf 10

log-adjacency-changes

network 0.0.0.0 255.255.255.255 area 0

default-information originate always

!

ip forward-protocol nd

ip route 0.0.0.0 0.0.0.0 FastEthernet0/1

!

!

ip http server

no ip http secure-server

ip nat inside source list 1 interface FastEthernet0/1 overload

!

access-list 1 permit 10.0.0.0 0.255.255.255

!

!        

!

control-plane

!

!

!

!

!

!

!

!

!

!

gatekeeper

shutdown

!

!

line con 0

logging synchronous

line aux 0

line vty 0 4

login

!

!        

end

Message was edited by: Josh Nansoz

11 Replies 11

Reza Sharifi
Hall of Fame
Hall of Fame

Hi,

can you change:

access-list 1 permit 10.0.0.0 0.255.255.255

to

access-list 1 permit 10.10.10.0 0.0.0.255

and test again?

HTH

woops I just updated the thread as they are in fact 2611 routers..not that that matters?

And I don't understand why that would help mate? surely the 10/8 network is okay as a statement?

I have the following vlans: 10.0.10.0     10.0.20.0     10.0.30.0

hi

im not shure if it helps but access list 1 is not enabled on fastethernet 0/0 ???

No mate that is not the issue.

The access list is there to say what should be allowed to pass through the NAT process and what shouldn't be. Not what should and shouldn't go through the interface.

Hi,

you want the router to be a DNS proxy ?  if so you need ip dns server global config command.

I also recommend changing your static route:

no ip route 0.0.0.0 0.0.0.0 FastEthernet0/1

ip route 0.0.0.0 0.0.0.0 FastEthernet0/1 dhcp

Regards.

Alain

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Don't forget to rate helpful posts.

Thanks will give it a go tonight...now the Router won't even ping the DNS servers or any servers that I know the IP of...

it is a weird one!

Hi,

With the modifications I suggested or without ?

Regards.

Alain

Don't forget to rate helpful posts.

Don't forget to rate helpful posts.

without!

I'll have to have a better look tonght when I get back from work.

Does the rest of the config look okay?

Thanks

Josh

Hi,

yes it looks good.

So pinging 8.8.8.8 from router is not working?

have you got an IP assigned on f0/1 ---> sh ip int br | exc una

have you got  the default route installed ----->  sh ip route static

Can you clear arp cache:  clear arp interface f0/1

change the default route as suggested  and ping again , is it working now ?

Regards.

Alain

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Don't forget to rate helpful posts.

Many thanks Cadet it works now

However the max speed I seem to be getting is about 20 meg.

Surely the 2611 can do at least half of a fast ethernet connect? e.g. around 50 meg which is what my BB speed should be?

I have just had a look online and it seems that about 10-20 meg (depending on what kind of filtering you are doing) is about right for this 2611.

Thanks for the help!

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