Panasonic NN46240-710 - Manual (Page 117)

Nortel Secure Router 8000 Series
Troubleshooting - VPN___________ 4 MPLS L2VPN troubleshooting
PPP
Frame Relay
• The minimum VLAN IDs of the neighboring PE and CE must be the same; while that of
the CEs on two ends of the tunnel can be di^erent.
The processing of ARP packets:
• After IP-interworking encapsulation, the Ethernet interface will have ARP entries that are
different from ordinary entries.
• On receiving an ARP request from CE, the IP interworking-encapsulated Layer 2 VPN
incoming interface of PE will respond with its own MAC address regardless of the
destination.
• An Ethernet interface or subinterface of PE can connect only one CE, it cannot connect
multiple CEs by using a hub or LAN switch. Otherwise, PE can learn useless MAC
addresses, leading to forwarding failure.
• PPP supports the Password Authentication Protocol (PAP) and Challenge-Handshake
Authentication Protocol (CHAP) authentication. PPP supports local, Remote
Authentication Dial-In User Service (RADIUS), and HWTACACS authentication.
• PPP supports STAC-LZS compression other than Internet Protocol Header Compression
(IPHC) and Van Jacobsen (VJ) compression.
• PE can assign IP addresses for CEs; CE can also assign IP addresses for PEs. The
mechanism of address allocation is similar to the common case.
• PPP supports transparent transmission of IP packets rather than MPLS, Intermediate
System-to-Intermediate System (IS-IS), and Internetwork Packet Exchange (IPX) packets
from a local CE to a remote CE. If any of these protocols is configured on the interface,
NCP will still be negotiated but the protocol packet will not be forwarded.
CQ NOTE
For PPP links, Nortel recommends that you select the way CE allocates IP addresses to PE. This can avoid
address conflict on PE and facilitate network deployment.
• Supports FRF.9 compression but does not support compression of the IP header in the
Frame Relay (FR) frame.
• Supports the Local Management Interface (LMI) protocol.
• Supports the Inverse Address Resolution Protocol (INARP).
• Supports transparent transmission of IP packets from a local CE to a remote CE, but does
not support that of MPLS packets, IS-IS packets, and IPX packets.
When you configure FR, note the following points:
• You must specify a VC number for an interface of data communications equipment (DCE)
or network-to-network interface (NNI) type, whether it is a main interface or a
subinterface.
• For an interface of data terminal equipment (DTE) type, if it is a main interface, the system
can automatically determine the VC number based on the remote device; if it is a
subinterface, you must manually specify a VC number for it.
4.2 Layer 2 VPN troubleshooting
This section covers the following topics:
Issue 5.3 (30 March 2009) Nortel Networks Inc. 4-7