Re: 1352 NUL bytes at the end of a page? (was Re: Assertion `s && s->tree' failed: The saga continues.)

From: Lincoln Dale
Date: Fri May 14 2004 - 22:18:13 EST


At 02:53 AM 15/05/2004, Andy Isaacson wrote:
That corruption size really does make me think of network packets, so
I'm tempted to blame it on PPP. Can you find out the MTU of your PPP
link? "ifconfig ppp0" or something like that.

1352 bytes coule be remarkably close to the TCP MSS . . .
perhaps there is some interaction with ppp where there is an overrun / lost packet and the TCP window is mistakenly advanced?

i.e.
- 1500 byte MTU
- less 28 bytes for PPP header (1472 bytes)
- less 20 bytes for IP header (1452 bytes)
- less 20 bytes for TCP header (1432 bytes)

if, however, the MRU is actually negotiated to be 1420 rather than 1500 . . .


when you issue the "bk pull", it may be interesting to see the output from:
tcpdump -i ppp0 -n | grep mss


cheers,

lincoln.

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