Linux pppd - lcp config failures on debian 8 pppd 2.4.6 but works on ubuntu 22.0 with pppd 2.4.9 - CHAP challenge appears after confrej

Question

I hope someone can help me

I have a Teltonika modem with a Wireless Logic SIM which we are driving using the Linux pppd daemon over a serial port and Im trying to work out why I cant get past authentication on an older Debian linux with pppd 2.4.6 (which we cant upgrade) when I can with a later version on Ubuntu. It seems the older system wants to reject "auth chap MD5" finally hanging on a "Discarded non-LCP packet when LCP not open" error. Ive been looking at the pppd man pages for hours and i cant find a solution! PPP debug output below at bottom of post

Chat file is

TIMEOUT 60
ECHO ON
ABORT '\nBUSY\r'
ABORT '\nERROR\r'
ABORT '\nNO ANSWER\r'
ABORT '\nNO CARRIER\r'
ABORT '\nNO DIALTONE\r'
'' ATZ
OK 'AT+CGDCONT=1,"IP","wlapn.com"'
OK ATD*99***1#
CONNECT ''

Peer file is

cp-echo-failure 0
lcp-echo-interval 0
#nodetach
debug
connect "/usr/sbin/chat -v -f /etc/chatscripts/wireless-logic"
/dev/ttyUSB0
115200
crtscts
noipdefault
default-asyncmap
defaultroute
nobsdcomp
noauth
passive
persist
ipcp-accept-local
ipcp-accept-remote
user R2PUKSYS
password R2PUKSYS
usepeerdns
lock
novj
show-password

Debug of non-working version where it just ends after the final error, also notice CHAP challenge seems to appear even after we've rejected???

ATZ
OK
AT+CGDCONT=1,"IP","wlapn.com"
OK
ATD*99***1#
CONNECT
Script /usr/sbin/chat -v -f /etc/chatscripts/gprs finished (pid 3229), status = 0x0
Serial connection established.
using channel 9
Using interface ppp0
Connect: ppp0 <--> /dev/ttyS2
sent [LCP ConfReq id=0x1 <magic 0x9fec45d1> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x2a <asyncmap 0x0> <auth chap MD5> <magic 0xd13c8cca> <pcomp> <accomp>]
sent [LCP ConfRej id=0x2a <asyncmap 0x0>]
rcvd [LCP ConfReq id=0x2b <auth chap MD5> <magic 0xd13c8cca> <pcomp> <accomp>]
sent [LCP ConfAck id=0x2b <auth chap MD5> <magic 0xd13c8cca> <pcomp> <accomp>]
rcvd [LCP DiscReq id=0x2c magic=0xd13c8cca]
sent [LCP ConfReq id=0x1 <magic 0x9fec45d1> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x2d <asyncmap 0x0> <auth chap MD5> <magic 0xd13c9885> <pcomp> <accomp>]
sent [LCP ConfRej id=0x2d <asyncmap 0x0>]
rcvd [LCP ConfReq id=0x2e <auth chap MD5> <magic 0xd13c9885> <pcomp> <accomp>]
sent [LCP ConfAck id=0x2e <auth chap MD5> <magic 0xd13c9885> <pcomp> <accomp>]
rcvd [LCP DiscReq id=0x2f magic=0xd13c9885]
LCP: timeout sending Config-Requests
rcvd [CHAP Challenge id=0x2 <fa05d11a50d2b1b27348a897aa62ab92>, name = "UMTS_CHAP_SRVR"]
Discarded non-LCP packet when LCP not open
rcvd [CHAP Challenge id=0x3 <0692e9e924970fcd3bc39cf1c0ebdfaf>, name = "UMTS_CHAP_SRVR"]
Discarded non-LCP packet when LCP not open
rcvd [CHAP Challenge id=0x4 <a513a0bbc0a57e3769a6cf74883dc16e>, name = "UMTS_CHAP_SRVR"]
Discarded non-LCP packet when LCP not open
rcvd [CHAP Challenge id=0x5 <62434f6aabb3f3c981c572115fcb298c>, name = "UMTS_CHAP_SRVR"]
Discarded non-LCP packet when LCP not open
rcvd [CHAP Challenge id=0x6 <4e25351af6614f8d2cd4921f49186666>, name = "UMTS_CHAP_SRVR"]
Discarded non-LCP packet when LCP not open

Working connection on Ubuntu - same modem same config

OK
AT+CGDCONT=1,"IP","wlapn.com"
OK
ATD*99***1#
CONNECT
Script /usr/sbin/chat -v -f /etc/chatscripts/wireless-logic finished (pid 8876), status = 0x0
Serial connection established.
using channel 1
Using interface ppp0
Connect: ppp0 <--> /dev/ttyUSB0
sent [LCP ConfReq id=0x1 <magic 0x77d321f9> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x0 <asyncmap 0x0> <auth chap MD5> <magic 0x2d03c0b> <pcomp> <accomp>]
sent [LCP ConfRej id=0x0 <asyncmap 0x0>]
rcvd [LCP ConfAck id=0x1 <magic 0x77d321f9> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x1 <auth chap MD5> <magic 0x2d03c0b> <pcomp> <accomp>]
sent [LCP ConfAck id=0x1 <auth chap MD5> <magic 0x2d03c0b> <pcomp> <accomp>]
rcvd [LCP DiscReq id=0x2 magic=0x2d03c0b]
rcvd [CHAP Challenge id=0x1 <b85176b8ba400effcb027573e0394a5e>, name = "UMTS_CHAP_SRVR"]
sent [CHAP Response id=0x1 <97247cf226529819c7d9cf5a16345f7c>, name = "********"]
rcvd [CHAP Success id=0x1 ""]
CHAP authentication succeeded
CHAP authentication succeeded
sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15>]
sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
sent [IPV6CP ConfReq id=0x1 <addr fe80::2c99:da39:1484:84a0>]
rcvd [LCP ProtRej id=0x3 80 fd 01 01 00 0c 1a 04 78 00 18 04 78 00]
Protocol-Reject for 'Compression Control Protocol' (0x80fd) received
rcvd [IPCP ConfReq id=0x0]
sent [IPCP ConfNak id=0x0 <addr 0.0.0.0>]
rcvd [IPCP ConfNak id=0x1 <addr 10.94.158.0> <ms-dns1 10.4.0.240> <ms-dns2 10.4.0.230>]
sent [IPCP ConfReq id=0x2 <addr 10.94.158.0> <ms-dns1 10.4.0.240> <ms-dns2 10.4.0.230>]
rcvd [IPCP ConfReq id=0x1]
sent [IPCP ConfAck id=0x1]
rcvd [IPCP ConfAck id=0x2 <addr 10.94.158.0> <ms-dns1 10.4.0.240> <ms-dns2 10.4.0.230>]
Could not determine remote IP address: defaulting to 10.64.64.64
Script /etc/ppp/ip-pre-up started (pid 8888)
Script /etc/ppp/ip-pre-up finished (pid 8888), status = 0x0
not replacing default route to wlp59s0 [10.20.31.254]
local  IP address 10.94.158.0
remote IP address 10.64.64.64
primary   DNS address 10.4.0.240
secondary DNS address 10.4.0.230
Script /etc/ppp/ip-up started (pid 8893)
Script /etc/ppp/ip-up finished (pid 8893), status = 0x0

Any ideas???

Peter

Answer 1

Finally found the solution to this ... it didnt seem to like the baud rate i was using .. I have an Olimex board which is a lower i reduced to 19200 and it worked fine