| 1:
| What is the initial message used in PPTP tunnel negotiation? |
| A1:
| Answer: The initial message is the Start-Control-Connection-Request (SCCRQ). |
| 2:
| If the remote access client/PNS is sending PPTP control channel messages, but those messages are not being received by the PAC, what are some possible causes? |
| A2:
| Answer: Lack of basic IP connectivity, an access-list blocking TCP port 1723. |
| 3:
| How is the tunnel session established between the remote access client/PNS and the PAC? |
| A3:
| Answer: The remote access client/PNS sends a OCRQ, and the PAC replies with an OCRP. |
| 4:
| How are data tunnel packets transmitted between the remote access client/PNS and the PAC? |
| A4:
| Answer: Data tunnel packets are transmitted using Enhanced GRE. |
| 5:
| The remote access client/PNS and the PAC successfully authenticate each other using standard MD5 CHAP, but then MPPE negotiation fails. What is the issue here? |
| A5:
| Answer: MPPE requires MS-CHAP authentication. |
| 6:
| Tunnel setup fails between the remote access client/PNS and the PAC. When debugging PPP negotiation, the following message is seen: O PROTREJ [Open] id 232 len 16 protocol CCP. What does this message reveal? |
| A6:
| Answer: This message indicates that the PAC has rejected configuration of the CCP, including MS-PPC and MPPE. |
| 7:
| During IPCP negotiation, the following message is seen, IPCP: Cannot satisfy pool request. What does this indicate? Assume that local IP address assignment is being used. |
| A7:
| Answer: This indicates that the IP address pool has been incorrectly configured or that there are no addresses left to allocate. |
| 8:
| The network administrator issues the command clear vpdn tunnel pptp remote_access_client/PNS_name PAC_name. What messages are exchanged between the remote access client/PNS and the PAC as the tunnel is terminated? |
| A8:
| Answer: The PAC first sends a CDN to the remote access client/PNS. This is immediately followed by a Stop-Control-Connection-Request (StopCCRQ). The remote access client/PNS replies with a Stop-Control-Connection-Reply, and the tunnel is down. |
| 9:
| Windows remote access client/PNS users are complaining of Internet reachability issues when connected to the PAC via a PPTP tunnel. What is most likely the issue here? |
| A9:
| Answer: The remote access client/PNS most likely has a split tunnel issue. This means that the default route on the remote access client/PNS is causing Internet-bound packets to be sent via the PPTP tunnel to the PAC, rather than directly to the ISP. |
| 10:
| A remote access client/PNS user wishes to configure Multilink PPP on the PPTP tunnel to the PAC. How can this be supported on the PAC? |
| A10:
| Answer: Multilink PPP is not supported on PPTP tunnels with Cisco routers. |
