I have a brand new Cisco C1111-8P router that is replacing a C871-K9 router. My ISP uses PPPoE to authenticate over an Ethernet circuit. My Cisco 871 router and associated wiring works fine and has for years. I have the same PPPoE configuration on the 1111 router but cannot establish a connection with my ISP. Here is what I have tested:
1. The old C871 works just fine. When I plug in the cable I immediately get a link light and within a few seconds the PPPoE is up and running.
2. I plug the exact same cable into port GE0/0/0 on the 1111 router and I don't even get a link light. I confirmed with my ISP they are not even seeing any attempts to authenticate. I have tried both a straight through and crossover cable just to be sure and there is no difference. The 871 works with a straight through cable.
3. If I insert a generic desktop Ethernet switch in between the ISP and port GE0/0/0 then I immediately get a link light and the 1111 does successfully authenticate. However, while the router does connect the throughput is so poor my desktop computer doesn't even think it has an Internet connection. I have tried using port GE0/0/1 as well and the result is the same.
The 1111 is a 10/100/1000 port whereas the 871 I believe is a 10/100 port. Other than that I don't see any difference. It seems like there is some kind of signaling problem. The circuit from the ISP is a Cat5e Ethernet cable, but they only terminate pins 1,2,3, and 6 in the cable. I included the relevant portions of my config below,
---
vpdn enable
vpdn-group 1
interface GigabitEthernet0/0/0
description connected to WAN
no ip address
negotiation auto
no cdp enable
pppoe enable group global
pppoe-client dial-pool-number 1
interface Dialer0
description WAN Dialer
ip address negotiated
ip nat outside
encapsulation ppp
dialer pool 1
dialer-group 1
no cdp enable
ppp authentication pap callin
ppp pap sent-username USERNAME password 7 PASSWORD
ppp ipcp route default
ip virtual-reassembly
dialer-list 1 protocol ip permit
