Date: Thu, 2 Aug 2007 07:03:55 +1000 (EST) From: Bruce Evans <brde@optusnet.com.au> To: Bruce Evans <brde@optusnet.com.au> Cc: "Chauncey N. Menefee" <cmenefee@prism-grp.com>, =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>, freebsd-gnats-submit@freebsd.org, freebsd-i386@freebsd.org Subject: Re: i386/115054: NTP errors out on startup but restart of NTP fixes problem Message-ID: <20070802065409.Y76975@delplex.bde.org> In-Reply-To: <20070802060947.O76862@delplex.bde.org> References: <200707301716.l6UHG3eD020378@www.freebsd.org> <20070731072434.F5028@besplex.bde.org> <86odhrlb18.fsf@ds4.des.no> <20070802060947.O76862@delplex.bde.org>
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On Thu, 2 Aug 2007, Bruce Evans wrote:
> On Wed, 1 Aug 2007, [utf-8] Dag-Erling Smørgrav wrote:
>
>> Bruce Evans <brde@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@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
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