[lwip-users] Re: PPP negotiate process

[yueyue papa]

from the log the major problem is after CHAP success.

Request peer address, and got a fcs error.
#######################
pppInProc[0]: got 10 bytes
pppInput[0]: IPCP len=4
fsm_input(IPCP):1,0,4
fsm_rconfreq(IPCP): Rcvd id 0 state=6 (LS_REQSENT)
ipcp_reqci: Requesting peer address
ipcp_reqci: returning Configure-NAK
pppWrite[0]: len=18
Written 18 bytes:
7e ff 03 80 21 03 00 00 0a 03 06 00 00 00 00 a0     ~...!...........
3d 7e                                               =~

fsm_sdata(IPCP): Sent code 3,0,10.
Read 29 bytes:
7e 80 21 03 01 00 16 03 06 0d 0a 44 09 82 81 06     ~.!........D....
d3 88 70 32 83 06 d3 88 14 cb bc a0 7e              ..p2........~

pppInProc[0]: got 29 bytes
pppInProc[0]: Dropping bad fcs 0xAD6A proto=0x8021
#########################


#########################
fsm_sdata(IPCP): Sent code 1,2,14.
IPCP: sending Configure-Request, id 2
Read 21 bytes:
7e 80 21 04 02 00 0e 01 0d 0a 00 00 00 00 00 00     ~.!.............
00 00 66 f7 7e                                      ..f.~

pppInProc[0]: got 21 bytes
pppInProc[0]: Dropping bad fcs 0xFC02 proto=0x8021
#########################

I got many 29 and 21 bytes fcs error.  

How could I confirm this is really FCS error, or some other protocol ?

Lee