i have the same issue with my 1801 and my ISP (BT broadband MAX DSL 8mb) thing is i was getting this before i upped to 8mb dsl. same issue where the ATM0 int goes down, put in the provided router and hand off via ethernet and all is well. parts of my config below (with user/pass removed)
as this only happens when im connected via dsl ive omitted the rest of the config so below is the dsl specifics only.
interface ATM0
description Master ADSL
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
ip virtual-reassembly
no ip mroute-cache
no atm auto-configuration
no atm ilmi-keepalive
no atm address-registration
no atm ilmi-enable
pvc 0/38
encapsulation aal5mux ppp dialer
dialer pool-member 1
!
dsl operating-mode auto
end
*
interface Dialer0
ip address negotiated
ip mtu 1492
ip nat outside
no ip virtual-reassembly
encapsulation ppp
ip tcp adjust-mss 1452
dialer pool 1
dialer idle-timeout 0
dialer persistent delay 60
dialer-group 1
no cdp enable
ppp authentication chap pap callin
ppp chap hostname ****
ppp chap password 7 ****
ppp pap sent-username ***
end
*
interface Loopback0
ip address * secondary
ip address * secondary
ip address *
ip mtu 1492
no ip route-cache
ip tcp adjust-mss 1452
hold-queue 100 out
any help you can shed would be great
