Cisco 871 Router Connecting to an ISP Using DHCP

Hi Ladies and Gentlemen,

here is a small problem for you, I have a 871 router that I can connect to my Cable modem and successfully get an ip address on the wan interface, now here are the problems :

1) Can I set the 871 as the DNS server and point all the clients to that rather than an external DNS Server

2) How can I setup a Lan to Lan on this configuration.

Thanks

Reply to
Ginger
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Ginger schrieb:

yes.

ip dns server

configure the DHCP server accordingly

Depends on how the counterpart is configured and your IOS feature set. If you have static ip addresses on both sides and Cisco routers on both sides GRE over IPsec is secure and quite simple to setup.

If you have Advanced IP Services IOS on all sites I would recommed DMVPN. Easy setup, only one fixed ip address necessary.

The 870 routers all can do standard IPsec and with DynDNS you can also setup a tunnel with dynamic ip addresses on both sides. It works, but it's quite tricky and not supported by TAC. You cannot use routing protocols or multicast over a standard IPsec connection using crypto maps.

Reply to
Uli Link

Hi Uli,

thank you for your prompt reply and help, I have tried 'ip dns server' but its not very fast it usually gives a timeout error then the result.

The other problem I am having is routing in general with out a lan to lan, if I try to set the router up as a pure internet router I cannot get any traffic outside of my network. I am connected to a Cable Modem that I can ping out from the IOS.

Any clues

Thanks

Reply to
Ginger

Ginger schrieb:

Your router must have DNS server(s) configured. With recent IOS the DNS servers can be provisioned via DHCP or IPCP by the provider. In doubt better configure them manually.

Quite a few. First is to check the NAT/PAT rules, next is the default route. For more it's helpful to see the config (without passwords and maybe symbolized ip addresses)

Reply to
Uli Link

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