Differences

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--- soc:2010:cooldavid:journal:week8 [2010/07/12 15:40]
cooldavid created
+++ soc:2010:cooldavid:journal:week8 [2010/07/19 19:11] (current)
cooldavid
@@ Line 24: / Line 24: @@
 gPXE did not check the ACK number while receiving a response from remote
 server with ACK flag set. gPXE assumes the remote server ACKed the SYN/FIN
-sent by gPXE if *ANY* received a packet from remote server with ACK flag
+sent by gPXE if **ANY** received a packet from remote server with ACK flag
 set. The error might occur when the packet is out-of-order.
@@ Line 32: / Line 32: @@
 to remote host instead of ignoring it.
-==== gPXE scheduling and program flow documentation ====
+=== Waiting for TCP to fully close ===
-Doing a note.
+While using scripts, if the downloaded image is not bootable,
+the gPXE exits faster than it have the opportunity to gracefully
+closing the TCP connection. Which might lead the TCP state of
+remote server not closed.
+[[http://git.etherboot.org/?p=people/cooldavid/gpxe.git;a=commitdiff;h=0bee38ff68e777ca2f563a2d7d5348cfe533232c|This commit]] waits for TCP
+to fully close by polling remaining ACKs from remote server and let
+the gPXE reply the correct response before shutdown the xfer interface.
+It is somehow hacky, hoping we can find better solution.
+=== Randomize TCP bind port ===
+To reduce possible TCP port collision.