Router 1841 with ADSL dinamyc IP

[Alejandro Cortes Rivera]

Any idea on how to avoid problems when the public IP change, cus when it happens the routers stay with the old IP and the internet service is lost.

[paolo bevilacqua]

That should not happen, because the ISP should not change public IP before the DHCP lease time expires.

In any case you might get better results by using an 871 or 1801 router with a native ADSL interface instead of the external modem.

[Alejandro Cortes Rivera]

I have a 1841 configured with dialer the external modem is in bridge mode, just works like media converter.

the interface dialer does not refresh the new public ip address.

any idea?

[paolo bevilacqua]

I understand that, and if you have dialer as opposed to DHCP, that is one reason more why it should not happen, because PPPoE have keepalives that bring the interface down if the service becomes unavailable.

And, the recommendation of using a router with native ADSL interface, is because in case the circuit flaps, the router would automatically re-espablish a new PPP session.

[Alejandro Cortes Rivera]

I have a 1841 configured with dialer the external modem is in bridge mode, just works like media converter.

the interface dialer does not refresh the new public ip address.

I need to apply shut, then no shut to refresh the publicj ip address in the dialer interface.

any idea?

[paolo bevilacqua]

What I'm telling you, is that this a problem with the ISP.

Once the PPP session is established, the ISP is not allowed to change your IP address without tearing down the session first.

You may want to check that you have keepalive enabled on your dialer interface.