cisco and telewest/virgin media

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Can anyone offer any advice for configuring a cisco router to use a
Telewest connection? I have the router plugged into the modem but when i
configure the details from a normal belkin router i can not see the
outside world :(

Re: cisco and telewest/virgin media
To aid in the accurace of this information, what is the router model and IOS
There is not enough information to resolve this, but here are some

Telewest appears to be a cable providor.  This means you have a cable modem
providing an ethernet connection into your router.
I have had experience with some American cable Internet where you need to
lease a DHCP IP address in order to connect out to the Internet.  Simply
configuring a static IP address will not work for some providors unless it
is an actual completed DHCP lease.  If that is not the case with your
service providor, make very sure that you have what is called a static
default route with the correct next hop IP address.

 * What is the result of the command "show ip route" on your router?

 * Can you PING your default gateway?

 * Does your router support the command "ip address dhcp" on the Internet
connecting interface?

 * Do you get resolved IP addresses to MAC addresses in your "show ip arp"

Once a cable modem does a media transition to ethernet, there should not be
any factors specific to the providor other that PPP authentication or
resetting the cable"modem" after connecting to a new ethernet device.

     Scott Perry
Indianapolis, Indiana

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Re: cisco and telewest/virgin media

     Cisco 2612 router connected successfully to the Internet using DHCP =
on the integrated Ethernet 0 interface.
     Cisco 2612 router connected successfully to Cisco 1600 on the =
serial interface.  1600 to 2612 communication is good.
     Cisco 1600 has a entry in its routing table for the default route = which points to the serial interface IP address of the 2612.

     Cisco 1600 cannot reach Internet

     IP addresses used within the LAN are private IP addresses (RFC1918)
     Example: 10.X.X.X or 172.16-31.X.X or 192.168.X.X

Proposed Solution:
     Enable NAT on the Cisco 2612 for LAN traffic to the Internet =

There is only one device on your network which has a global Internet IP =
address, the Cisco 2612.  No other device in your network can get =
communicate on the Internet with private IP addresses (RFC1918).  Enable =
NAT on the 2612 using commands similar to the following:
  interface Ethernet 0
   ip nat outside
  interface Serial 0
   ip nat inside
  ip access-list standard NAT-List
   permit W.X.Y.Z M.A.S.K
  ip nat inside source list NAT-List interface Ethernet 0 overload
W.X.Y.Z M.A.S.K is the range of inside IP addresses which will be =
translated with NAT out to the Internet.

Diagnose NAT on the 2600 with this command:  show ip nat translations

Reference Cisco's website (follow the links as shown below):
 - Support
 - Documentation
 - IP
 - Network Address Translation (NAT)

Reference RFC1631:

     Scott Perry
Indianapolis, Indiana
________________________________________    =20

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Re: cisco and telewest/virgin media

Its a 2612 running c2600-i-mz.122-12a.bin. I have managed to get the WAN
side connected using DHCP but im now having an issue with the LAN. The
2612 only has 1 ethernet interface which is used for the WAN, I was
planning ti use the serial WIC to route all LAN traffic over the serial
link to a 1600 series router and then have a some wireless router
plugged into the ethernet port of that, is this possible? I can ping
internally OK on the LAN from the cisco 1600 but as soon as i try to
ping anything outside the LAN it fails

Scott Perry wrote:
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Re: cisco and telewest/virgin media
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Maybe better that you copy and paste the results when do a show

Just blank out the sensetive information as that we could then see the type
of router and the IOS version installed.

Re: cisco and telewest/virgin media
Do you have default routes on the routers and are the hosts on the LAN
pointing at the 1600 as the default gateway?(you'll need to point it at the
WAP when you install that)
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