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IP Cef with nat in pppoe conf

I have a question:

When i disable ip cef the pppoe client session work ok and when I enable ip cef have not connection .Where is the problem.

this is the configuration:

aaa authentication login default local

aaa authentication ppp default local group radius

aaa authorization network default if-authenticated

aaa accounting network default start-stop group radius

ip cef

username xxx password xxx


bba-group pppoe pppoevlan1

virtual-template 140

sessions per-vc limit 500


interface GigabitEthernet0/1

ip address x.x.x.246

ip nat outside

interface GigabitEthernet0/2

no ip address

interface GigabitEthernet0/2.1

description PPPOE VLAN 1

encapsulation dot1Q 1 native

ip address

ip virtual-reassembly

no snmp trap link-status

pppoe enable group pppoevlan1


interface Virtual-Template140

ip unnumbered GigabitEthernet0/2.1

ip nat inside

ip virtual-reassembly

peer default ip address pool pppoevlan1

ppp authentication chap

ppp multilink


ip local pool pppoevlan1

ip nat inside source list 40 pool pppoenat overload

access-list 40 permit


Re: IP Cef with nat in pppoe conf

TCP traffic may get dropped if Cisco Express Forwarding (CEF) and Network Address Translation (NAT) are both enabled.

Make sure you are using the version 12.2.8T.