Bug 29342

As far as I can tell, a change was made between version 1.81.2.4 and 1.81.2.8 of /usr/src/usr.sbin/ppp/lcp.c which breaks dialup access with my ISP, Innercite.

The LCP debug output isn't very descriptive, so I can't be more specific, it simply fails a negotiation and drops the connection:

Jul 30 20:02:41 squirt ppp[573]: LCP:  MRU[4] 2048
Jul 30 20:02:41 squirt ppp[573]: LCP: deflink: RecvConfigReq(2) state = Ack-Rcvd

Jul 30 20:02:41 squirt ppp[573]: LCP:  MRU[4] 1524
Jul 30 20:02:41 squirt ppp[573]: LCP:  ACCMAP[6] 0x00000000
Jul 30 20:02:41 squirt ppp[573]: LCP:  AUTHPROTO[4] 0xc023 (PAP)
Jul 30 20:02:41 squirt ppp[573]: LCP:  PROTOCOMP[2]
Jul 30 20:02:41 squirt ppp[573]: LCP:  ACFCOMP[2]
Jul 30 20:02:41 squirt ppp[573]: LCP:  ENDDISC[9] MAC 00:c0:7b:8a:9e:22
Jul 30 20:02:41 squirt ppp[573]: LCP: deflink: SendConfigNak(2) state = Ack-Rcvd

Jul 30 20:02:41 squirt ppp[573]: LCP:  MRU[4] 2048
Jul 30 20:02:41 squirt ppp[573]: LCP: deflink: RecvTerminateReq(3) state = Ack-R
cvd
Jul 30 20:02:41 squirt ppp[573]: LCP: deflink: SendTerminateAck(3) state = Ack-R
cvd
Jul 30 20:02:41 squirt ppp[573]: LCP: deflink: State change Ack-Rcvd --> Req-Sen


ppp.conf is very simple:
default:

 set device /dev/cuaa0

 set log Phase Chat Command
 set speed 115200
 set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \"\" AT OK-AT-OK \\dATDT\\T TIMEOUT 40 CONNECT"

 set timeout 0

 nat enable yes
 nat log yes

 set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.0 0.0.0.0
 add default HISADDR

innercite:
 set phone 5031525
 set authname ********
 set authkey ********

Most of the changes appear to be related to the MTU/MRU, but given the poor debug output, I can't tell exactly what the failure is.

Fix: 

N/A
How-To-Repeat: 1)  Use PPP with lcp.c version 1.81.2.8

2)  Dial any of Innercite's access numbers

3)  Watch it fail

I'm currently trying to find out what Innercite uses for its PPP servers.