TFTP opcode table
TFTP packet formats
2 bytes string 1 byte string 1 byte
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| Opcode | Filename | 0 | Mode | 0 |
------------------------------------------------
Figure 5-1: RRQ/WRQ packet
2 bytes 2 bytes n bytes
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| Opcode | Block # | Data |
----------------------------------
Figure 5-2: DATA packet
2 bytes 2 bytes
---------------------
| Opcode | Block # |
---------------------
Figure 5-3: ACK packet
2 bytes 2 bytes string 1 byte
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| Opcode | ErrorCode | ErrMsg | 0 |
-----------------------------------------
Figure 5-4: ERROR packet
TFTP network snap
Script started on Fri Mar 14 17:00:06 2003 sherman# tcpdump udp -s 5000 -X udp and not port domain tcpdump: listening on fxp0 17:00:41.829134 grant.cs.miami.edu.1594 > sherman.cs.miami.edu.tftp: 27 RRQ "small-hands.txt" 0x0000 4500 0037 2963 0000 4011 f921 ac14 0007 E..7)c..@..!.... 0x0010 ac14 0002 063a 0045 0023 6dee 0001 736d .....:.E.#m...sm 0x0020 616c 6c2d 6861 6e64 732e 7478 7400 6e65 all-hands.txt.ne 0x0030 7461 7363 6969 00 tascii. 17:00:41.834977 sherman.cs.miami.edu.4327 > grant.cs.miami.edu.1594: udp 516 0x0000 4500 0220 bb3f 0000 4011 655c ac14 0002 E....?..@.e\.... 0x0010 ac14 0007 10e7 063a 020c 3d1e 0003 0001 .......:..=..... 0x0020 536f 6d65 7768 6572 6520 4920 6861 7665 Somewhere.I.have 0x0030 206e 6576 6572 2074 7261 7665 6c6c 6564 .never.travelled 0x0040 2c20 676c 6164 6c79 2062 6579 6f6e 640d ,.gladly.beyond. 0x0050 0a61 6e79 2065 7870 6572 6965 6e63 652c .any.experience, 0x0060 796f 7572 2065 7965 7320 6861 7665 2074 your.eyes.have.t 0x0070 6865 6972 2073 696c 656e 6365 3a0d 0a69 heir.silence:..i 0x0080 6e20 796f 7572 206d 6f73 7420 6672 6169 n.your.most.frai 0x0090 6c20 6765 7374 7572 6520 6172 6520 7468 l.gesture.are.th 0x00a0 696e 6773 2077 6869 6368 2065 6e63 6c6f ings.which.enclo 0x00b0 7365 206d 652c 0d0a 6f72 2077 6869 6368 se.me,..or.which 0x00c0 2049 2063 616e 6e6f 7420 746f 7563 6820 .I.cannot.touch. 0x00d0 6265 6361 7573 6520 7468 6579 2061 7265 because.they.are 0x00e0 2074 6f6f 206e 6561 720d 0a0d 0a79 6f75 .too.near....you 0x00f0 7220 736c 6967 6874 6573 7420 6c6f 6f6b r.slightest.look 0x0100 2065 6173 696c 7920 7769 6c6c 2075 6e63 .easily.will.unc 0x0110 6c6f 7365 206d 650d 0a74 686f 7567 6820 lose.me..though. 0x0120 4920 6861 7665 2063 6c6f 7365 6420 6d79 I.have.closed.my 0x0130 7365 6c66 2061 7320 6669 6e67 6572 732c self.as.fingers, 0x0140 0d0a 796f 7520 6f70 656e 2061 6c77 6179 ..you.open.alway 0x0150 7320 7065 7461 6c20 6279 2070 6574 616c s.petal.by.petal 0x0160 206d 7973 656c 6620 6173 2053 7072 696e .myself.as.Sprin 0x0170 6720 6f70 656e 730d 0a28 746f 7563 6869 g.opens..(touchi 0x0180 6e67 2073 6b69 6c66 756c 6c79 2c6d 7973 ng.skilfully,mys 0x0190 7465 7269 6f75 736c 7929 2068 6572 2066 teriously).her.f 0x01a0 6972 7374 2072 6f73 650d 0a6f 7220 6966 irst.rose..or.if 0x01b0 2079 6f75 7220 7769 7368 2062 6520 746f .your.wish.be.to 0x01c0 2063 6c6f 7365 206d 652c 4920 616e 640d .close.me,I.and. 0x01d0 0a6d 7920 6c69 6665 2077 696c 6c20 7368 .my.life.will.sh 0x01e0 7574 2076 6572 7920 6265 6175 7469 6675 ut.very.beautifu 0x01f0 6c6c 792c 7375 6464 656e 6c79 2c0d 0a61 lly,suddenly,..a 0x0200 7320 7768 656e 2074 6865 2068 6561 7274 s.when.the.heart 0x0210 206f 6620 7468 6973 2066 6c6f 7765 7220 .of.this.flower. 17:00:41.835229 grant.cs.miami.edu.1594 > sherman.cs.miami.edu.4327: udp 4 0x0000 4500 0020 2965 0000 4011 f936 ac14 0007 E...)e..@..6.... 0x0010 ac14 0002 063a 10e7 000c 907e 0004 0001 .....:.....~.... 0x0020 0000 0000 0000 0000 0000 0000 0000 .............. 17:00:41.835333 sherman.cs.miami.edu.4327 > grant.cs.miami.edu.1594: udp 452 0x0000 4500 01e0 bb40 0000 4011 659b ac14 0002 E....@..@.e..... 0x0010 ac14 0007 10e7 063a 01cc e22d 0003 0002 .......:...-.... 0x0020 696d 6167 696e 6573 0d0a 7468 6520 736e imagines..the.sn 0x0030 6f77 2063 6172 6566 756c 6c79 2065 7665 ow.carefully.eve 0x0040 7279 7768 6572 6520 6465 7363 656e 6469 rywhere.descendi 0x0050 6e67 3b0d 0a0d 0a6e 6f74 6869 6e67 2077 ng;....nothing.w 0x0060 6869 6368 2077 6520 6172 6520 746f 2070 hich.we.are.to.p 0x0070 6572 6365 6976 6520 696e 2074 6869 7320 erceive.in.this. 0x0080 776f 726c 6420 6571 7561 6c73 0d0a 7468 world.equals..th 0x0090 6520 706f 7765 7220 6f66 2079 6f75 7220 e.power.of.your. 0x00a0 696e 7465 6e73 6520 6672 6167 696c 6974 intense.fragilit 0x00b0 793a 7768 6f73 6520 7465 7874 7572 650d y:whose.texture. 0x00c0 0a63 6f6d 7065 6c73 206d 6520 7769 7468 .compels.me.with 0x00d0 2074 6865 2063 6f6c 6f75 7220 6f66 2069 .the.colour.of.i 0x00e0 7473 2063 6f75 6e74 7269 6573 2c0d 0a72 ts.countries,..r 0x00f0 656e 6465 7269 6e67 2064 6561 7468 2061 endering.death.a 0x0100 6e64 2066 6f72 6576 6572 2077 6974 6820 nd.forever.with. 0x0110 6561 6368 2062 7265 6174 6869 6e67 0d0a each.breathing.. 0x0120 0d0a 2849 2064 6f20 6e6f 7420 6b6e 6f77 ..(I.do.not.know 0x0130 2077 6861 7420 6974 2069 7320 6162 6f75 .what.it.is.abou 0x0140 7420 796f 7520 7468 6174 2063 6c6f 7365 t.you.that.close 0x0150 730d 0a61 6e64 206f 7065 6e73 3b6f 6e6c s..and.opens;onl 0x0160 7920 736f 6d65 7468 696e 6720 696e 206d y.something.in.m 0x0170 6520 756e 6465 7273 7461 6e64 730d 0a74 e.understands..t 0x0180 6865 2076 6f69 6365 206f 6620 796f 7572 he.voice.of.your 0x0190 2065 7965 7320 6973 2064 6565 7065 7220 .eyes.is.deeper. 0x01a0 7468 616e 2061 6c6c 2072 6f73 6573 290d than.all.roses). 0x01b0 0a6e 6f62 6f64 792c 6e6f 7420 6576 656e .nobody,not.even 0x01c0 2074 6865 2072 6169 6e2c 6861 7320 7375 .the.rain,has.su 0x01d0 6368 2073 6d61 6c6c 2068 616e 6473 0d0a ch.small.hands.. 17:00:41.835546 grant.cs.miami.edu.1594 > sherman.cs.miami.edu.4327: udp 4 0x0000 4500 0020 2966 0000 4011 f935 ac14 0007 E...)f..@..5.... 0x0010 ac14 0002 063a 10e7 000c 907d 0004 0002 .....:.....}.... 0x0020 0000 0000 0000 0000 0000 0000 0000 .............. 159 packets received by filter 0 packets dropped by kernel sherman# exit Script done on Fri Mar 14 17:00:50 2003