The POS interface of NE40 is connected with that of the peer device. IS-IS should be enabled on the POS interface of NE40 only.
NE40 cannot import the direct route. After IS-IS is enabled on the POS interface, the IS-IS database of NE40 has no network segments.
Change NE40 as enterprise C's device. The device can import the direct route. Through further test, the direct route cannot be imported on the POS interface with PPP protocol.
The reasons are as follows:
<HE-SJ-QX-S-1.163>di is int
Interface IP Address Id Link.Sta IP.Sta MTU Type DR
LoopBack0 22.214.171.124 001 Up Up 1497 L2 No
Vlanif3 126.96.36.199 002 Up Up 1497 L2 No
Vlanif5 188.8.131.52 003 Up Up 1497 L2 No
Pos2/0/0 004 Up Down 4470 L2 --
Pos3/0/1 184.108.40.206 006 Down Up 4470 L2 --
Pos3/0/2 220.127.116.11 007 Down Up 4470 L2 --
Pos2/1/0 18.104.22.168 008 Down Up 4470 L2 --
Pos3/0/0 22.214.171.124 005 Down Up 4470 L2 --
The IS-IS interface is not Up, so the interface cannot be imported to LSP. IS-IS interface can be Up when the following conditions are satisfied: The interface is Up, IP is Up, and the MTU is Up. According to the preceding information, IP check of POS200 fails and Layer 2 protocol negotiation of the POS interface fails.
For other interfaces, if Layer 2 of the peer does not support OSI, enable IS-IS on the peer. Generally, when the device encapsulates PPP on the interface, it needs to negotiate OSICP with the peer. If OSICP is in the open state, the direct route can be imported. The implementation of enterprise C's device is different. After IS-IS is enabled on the interface, the route can be imported once the status of IPCP is OPEN. V5 version supports the function.
The version does not support.