i386/115054: NTP errors out on startup but restart of NTP fixes problem

[Bruce Evans]

On Thu, 2 Aug 2007, Bruce Evans wrote:

> On Wed, 1 Aug 2007, [utf-8] Dag-Erling Smørgrav wrote:
>
>> Bruce Evans <brde at optusnet.com.au> writes:
>>> Several versions of FreeBSD have annoying behaviouor for network
>>> startup, involving the network not actually being up when ifconfig
>>> returns and subsequent different mishandling of this by various
>>> utilities.  [...]
>>> This problem seems to get worse with each release of FreeBSD and/or
>>> with newer NICs.  I never noticed fxp or even ed or rl NICs.  Now it
>>> is barely noticeable with fxp and very noticeable with sk, bge and em
>>> NICs.
>> 
>> I have never seen this with any of the cards I've used (xl, fxp, rl, re,
>> sis, bge, sk, msk and probably others, in no particular order).
>> 
>> Perhaps there is a hardware issue involved?  Does the problem occur if
>> you hardcode the link speed instead of relying on autonegotiation?
>
> No difference.  I thought it might be the cheap switch, but going
> direct makes no difference except to break hard-coding the link speed
> for bge.  Thie followings is with bge (1Gbps capable but reduced to
> 100baseTX full-duplex by autonegotiation) under -current, connected
> to fxp (100baseTX full-duplex by autonegotiation or hard-coded) under
> FreeBSD-~5.2:
>
> [... ping hangs for 11+ seconds; "route get" hangs for 5 seconds]

The fastest way to get a working ping is to insert a delay of >= 2.9
seconds after "ifconfig up" (2.8 doesn't work -- it doesn't even reduce
the duration of the hangs by 2.8 seconds).  Then "route get" (ping next
still takes 11+ seconds.  Then ping works instantly:

%%%
ttyv1:root at besplex:/tmp> ifconfig bge0 down; time ifconfig bge0 up; sleep 2.9; t
ime route get delplex; time route get delplex; time ping -c1 delplex
         0.48 real         0.00 user         0.47 sys
    route to: delplex
destination: 192.168.2.0
        mask: 255.255.255.0
   interface: bge0
       flags: <UP,DONE,CLONING>
  recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
        0         0         0         0         0         0      1500        -3
         0.22 real         0.00 user         0.00 sys
    route to: delplex
destination: delplex
   interface: bge0
       flags: <UP,HOST,DONE,LLINFO,WASCLONED>
  recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
        0         0         0         0         0         0      1500      1200
         0.00 real         0.00 user         0.00 sys
PING delplex.bde.org (192.168.2.4): 56 data bytes
64 bytes from 192.168.2.4: icmp_seq=0 ttl=64 time=0.163 ms

--- delplex.bde.org ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.163/0.163/0.163/0.000 ms
         0.00 real         0.00 user         0.00 sys
%%%

The first "route get" still takes 0.22 seconds, and increasing the sleep time
doesn't reduce that, but it does reduce the expire time -- "sleep N" gives
an expire time of about -N seconds.

Bruce