mpd: two links make one disconnect (ENOBUFS, LCP no reply)

[Giovanni P. Tirloni]

Hi,

 The behaviour I'm having with mpd-3.15 is that it establishes the first
 connection in ng0 and when I try to open another connection it works
 but drops the first one after sometime because it stops answering the
 LCP echos. 

 When both are established I can ping the last one but the ping to the
 first IP returns ENOBUFS (probably because the link is being dropped).
 Anything related to the PPTP output window?

 Here is the log entries after both links are established (they show as
 connected in the win2k and winxp boxes and pptp0 was answering the LCP
 echos):

Dec 10 11:02:22 servidor mpd: [pptp1] exec: command returned 256 
Dec 10 11:02:22 servidor mpd: [pptp1] IFACE: Up event 
Dec 10 11:02:24 servidor mpd: [pptp1] ECP: SendConfigReq #4 
Dec 10 11:02:24 servidor mpd: [pptp1] LCP: rec'd Protocol Reject #9 link 0 (Opened) 
Dec 10 11:02:24 servidor mpd: [pptp1] LCP: protocol ECP was rejected 
Dec 10 11:02:24 servidor mpd: [pptp1] ECP: protocol was rejected by peer 
Dec 10 11:02:24 servidor mpd: [pptp1] ECP: state change Req-Sent --> Stopped 
Dec 10 11:02:24 servidor mpd: [pptp1] ECP: LayerFinish 
Dec 10 11:03:20 servidor mpd: [pptp0] LCP: no reply to 1 echo request(s) 
Dec 10 11:03:25 servidor mpd: [pptp0] LCP: no reply to 2 echo request(s) 
Dec 10 11:03:30 servidor mpd: [pptp0] LCP: no reply to 3 echo request(s) 
Dec 10 11:03:35 servidor mpd: [pptp0] LCP: no reply to 4 echo request(s) 
Dec 10 11:03:40 servidor mpd: [pptp0] LCP: no reply to 5 echo request(s) 
Dec 10 11:03:45 servidor mpd: [pptp0] LCP: no reply to 6 echo request(s) 
Dec 10 11:03:50 servidor mpd: [pptp0] LCP: no reply to 7 echo request(s) 
Dec 10 11:03:50 servidor mpd: [pptp0] LCP: peer not responding to echo requests 
Dec 10 11:03:50 servidor mpd: [pptp0] LCP: LayerFinish 
Dec 10 11:03:50 servidor mpd: [pptp0] LCP: LayerStart 
Dec 10 11:03:50 servidor mpd: [pptp0] LCP: state change Opened --> Starting 
Dec 10 11:03:50 servidor mpd: [pptp0] LCP: phase shift NETWORK --> DEAD 
Dec 10 11:03:50 servidor mpd: [pptp0] setting interface ng0 MTU to 1500 bytes 
Dec 10 11:03:50 servidor mpd: [pptp0] up: 0 links, total bandwidth 9600 bps 
Dec 10 11:03:50 servidor mpd: [pptp0] IPCP: Down event 
Dec 10 11:03:50 servidor mpd: [pptp0] IPCP: state change Opened --> Starting 
Dec 10 11:03:50 servidor mpd: [pptp0] IPCP: LayerDown 
Dec 10 11:03:50 servidor mpd: [pptp0] IFACE: Down event 
Dec 10 11:03:50 servidor mpd: [pptp0] exec: /sbin/route delete 192.168.1.253 -iface lo0 
Dec 10 11:03:50 servidor mpd: [pptp0] exec: /usr/sbin/arp -d 192.168.1.220 
Dec 10 11:03:50 servidor mpd: [pptp0] exec: /sbin/ifconfig ng0 down delete -link0 
Dec 10 11:03:50 servidor mpd: [pptp0] CCP: Down event 
Dec 10 11:03:50 servidor mpd: [pptp0] CCP: state change Opened --> Starting 
Dec 10 11:03:50 servidor mpd: [pptp0] CCP: LayerDown 
Dec 10 11:03:50 servidor mpd: [pptp0] CCP: Close event 
Dec 10 11:03:50 servidor mpd: [pptp0] CCP: state change Starting --> Initial 
Dec 10 11:03:50 servidor mpd: [pptp0] CCP: LayerFinish 
Dec 10 11:03:50 servidor mpd: [pptp0] ECP: Down event 
Dec 10 11:03:50 servidor mpd: [pptp0] ECP: state change Stopped --> Starting 
Dec 10 11:03:50 servidor mpd: [pptp0] ECP: LayerStart 
Dec 10 11:03:50 servidor mpd: [pptp0] ECP: Close event 

 # netstat -m
 mbuf usage:
         GEN cache:      0/0 (in use/in pool)
         CPU #0 cache:   2/256 (in use/in pool)
         Total:          2/256 (in use/in pool)
         Mbuf cache high watermark: 512
         Maximum possible: 27136
         Allocated mbuf types:
           2 mbufs allocated to data
         0% of mbuf map consumed
 mbuf cluster usage:
         GEN cache:      0/80 (in use/in pool)
         CPU #0 cache:   0/128 (in use/in pool)
         Total:          0/208 (in use/in pool)
         Cluster cache high watermark: 128
         Maximum possible: 13568
         1% of cluster map consumed
 480 KBytes of wired memory reserved (0% in use)
 0 requests for memory denied
 0 requests for memory delayed
 0 calls to protocol drain routines

 After much tweaking here is my mpd.conf:

 -------- mpd.conf -------

 default:
	 load pptp0
         load pptp1

 common:
         set bundle disable multilink
         set bundle enable compression
         set bundle yes encryption
         set ccp yes mppc
         set ccp yes mpp-e40
         set ccp yes mpp-e56
         set ccp yes mpp-e128
         set ccp yes mpp-stateless
         set ipcp enable vjcomp
         set iface enable proxy-arp
         set iface route 192.168.1.253/24
         set ipcp dns 1.2.3.4
         set link deny pap chap
         set link enable chap-md5 chap-msv1 chap-msv2
         set ipcp nbns 192.168.1.254


 pptp0:
         new -i ng0 pptp0 pptp0
         set ipcp ranges 192.168.1.253/32 192.168.1.220/24
         load common
 
 pptp1:
         new -i ng1 pptp1 pptp1
         set ipcp ranges 192.168.1.253/32 192.168.1.221/24
         load common

 -------- mpd.conf ---------

 Thanks in advance,

 --
 Giovanni P. Tirloni <gpt at tirloni.org>
 Fingerprint: 8C3F BEC5 79BD 3E9B EDB8  72F4 16E8 BA5E D031 5C26