[Dnsmasq-discuss] Wrong server IP in dual normal/proxyDHCP mode
Alkis Georgopoulos
alkisg at gmail.com
Wed May 20 05:24:02 BST 2015
Whoops sorry I think that I misunderstood the difference of the two
packets that I attached.
In both the successful and the unsuccessful boots, the transaction has
this exact message:
06:54:45.724145 3c:07:71:a2:02:e3 > c0:4a:00:02:bc:1e, ethertype IPv4
(0x0800), length 590: (tos 0x0, ttl 20, id 2, offset 0, flags [none],
proto UDP (17), length 576)
10.161.254.149.4011 > 10.161.254.11.4011: [udp sum ok] UDP, length 548
0x0000: c04a 0002 bc1e 3c07 71a2 02e3 0800 4500 .J....<.q.....E.
0x0010: 0240 0002 0000 1411 92c8 0aa1 fe95 0aa1 . at ..............
0x0020: fe0b 0fab 0fab 022c 41ca 0101 0600 72a2 .......,A.....r.
0x0030: 02e3 0004 0000 0aa1 fe95 0000 0000 0000 ................
0x0040: 0000 0000 0000 3c07 71a2 02e3 0000 0000 ......<.q.......
0x0050: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0060: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0070: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0080: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0090: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x00a0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x00b0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x00c0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x00d0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x00e0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x00f0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0100: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0110: 0000 0000 0000 6382 5363 3501 0337 2401 ......c.Sc5..7$.
0x0120: 0203 0405 060b 0c0d 0f10 1112 1617 1c28 ...............(
0x0130: 292a 2b32 3336 3a3b 3c42 4380 8182 8384 )*+236:;<BC.....
0x0140: 8586 8739 0204 ec61 1100 5048 dcb1 ba8a ...9...a..PH....
0x0150: e211 a00d 3c07 71a2 02e3 5d02 0000 5e03 ....<.q...]...^.
0x0160: 0102 013c 2050 5845 436c 6965 6e74 3a41 ...<.PXEClient:A
0x0170: 7263 683a 3030 3030 303a 554e 4449 3a30 rch:00000:UNDI:0
0x0180: 3032 3030 312b 0747 0480 0000 00ff ff00 02001+.G........
0x0190: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x01a0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x01b0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x01c0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x01d0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x01e0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x01f0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0200: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0210: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0220: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0230: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0240: 0000 0000 0000 0000 0000 0000 0000 ..............
Then the transaction has the packets that I attached in my previous
message, which are different.
What I misread was that in the successful case, there was a reply from
the server (10.161.254.11) to the client (10.161.254.149),
while in the unsuccessful case the client continued sending the same
packet like ^ above to the server for 4-5 times before it gave up.
So I'm guessing that the problem is that with the latest patch, the
server doesn't reply with the "ACK?" packet at all.
Thanks,
Alkis
On 20/05/2015 07:10 πμ, Alkis Georgopoulos wrote:
> On 20/05/2015 01:04 πμ, Simon Kelley wrote:
>> I just pushed a patch into git
>>
>> http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commitdiff;h=7f8565b94ca52dde31f7688a9f9a0cc611d9dae3
>>
>>
>> Please could you see if that helps? It should apply to the Ubuntu 14.04
>> version, if that's easier.
>
>
> Hi Simon,
>
> I tested against the git head version.
> It did fix the boot server's IP, i.e. the client now tried to download
> pxelinux.0 from the correct IP=10.161.254.11.
>
> Unfortunately it seems like it also broke PXE booting completely.
> Completely, as in, now the client won't boot either with or without
> #dhcp-range=tag:efi,192.168.68.20,192.168.68.250,8h
>
> The client now reports (after getting the IP, and at the point where
> it's supposed to download pxelinux.0):
> UD 10.161.254.11....|
> PXE-E78 - Could not locate boot server
>
> And aborts PXE boot.
>
>
> I'm attaching two packets which might help a bit if you compare them.
>
> The first is the last packet from 4011 in the successful case, i.e.
> without any patches at all, and with the "#dhcp-range=192.168.68.20..."
> line commented out. I'm guessing that what we want is to send the same
> packet even when that dhcp-range isn't commented out.
>
> 06:54:45.724239 c0:4a:00:02:bc:1e > 3c:07:71:a2:02:e3, ethertype IPv4
> (0x0800), length 342: (tos 0xc0, ttl 64, id 800, offset 0, flags [none],
> proto UDP (17), length 328)
> 10.161.254.11.4011 > 10.161.254.149.4011: [udp sum ok] UDP, length 300
> 0x0000: 3c07 71a2 02e3 c04a 0002 bc1e 0800 45c0 <.q....J......E.
> 0x0010: 0148 0320 0000 4011 63e2 0aa1 fe0b 0aa1 .H.... at .c.......
> 0x0020: fe95 0fab 0fab 0134 7345 0201 0600 72a2 .......4sE....r.
> 0x0030: 02e3 0004 0000 0000 0000 0aa1 fe95 0aa1 ................
> 0x0040: fe0b 0000 0000 3c07 71a2 02e3 0000 0000 ......<.q.......
> 0x0050: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0060: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0070: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0080: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0090: 0000 0000 0000 6c74 7370 2f69 3338 362f ......ltsp/i386/
> 0x00a0: 7078 656c 696e 7578 2e30 0000 0000 0000 pxelinux.0......
> 0x00b0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00c0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00d0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00e0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00f0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0100: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0110: 0000 0000 0000 6382 5363 3501 0536 040a ......c.Sc5..6..
> 0x0120: a1fe 0b3c 0950 5845 436c 6965 6e74 6111 ...<.PXEClienta.
> 0x0130: 0050 48dc b1ba 8ae2 11a0 0d3c 0771 a202 .PH........<.q..
> 0x0140: e32b 0747 0480 0000 00ff ff00 0000 0000 .+.G............
> 0x0150: 0000 0000 0000 ......
>
>
> The second is the last packet from 4011 with the latest patch applied
> and with the "dhcp-range=192.168.68.20..." in effect. Now tt's a lot
> longer than the successful one:
>
> 07:00:57.059681 3c:07:71:a2:02:e3 > c0:4a:00:02:bc:1e, ethertype IPv4
> (0x0800), length 590: (tos 0x0, ttl 20, id 5, offset 0, flags [none],
> proto UDP (17), length 576)
> 10.161.254.149.4011 > 10.161.254.11.4011: [udp sum ok] UDP, length 548
> 0x0000: c04a 0002 bc1e 3c07 71a2 02e3 0800 4500 .J....<.q.....E.
> 0x0010: 0240 0005 0000 1411 92c5 0aa1 fe95 0aa1 . at ..............
> 0x0020: fe0b 0fab 0fab 022c 41c4 0101 0600 72a2 .......,A.....r.
> 0x0030: 02e3 000a 0000 0aa1 fe95 0000 0000 0000 ................
> 0x0040: 0000 0000 0000 3c07 71a2 02e3 0000 0000 ......<.q.......
> 0x0050: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0060: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0070: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0080: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0090: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00a0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00b0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00c0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00d0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00e0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x00f0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0100: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0110: 0000 0000 0000 6382 5363 3501 0337 2401 ......c.Sc5..7$.
> 0x0120: 0203 0405 060b 0c0d 0f10 1112 1617 1c28 ...............(
> 0x0130: 292a 2b32 3336 3a3b 3c42 4380 8182 8384 )*+236:;<BC.....
> 0x0140: 8586 8739 0204 ec61 1100 5048 dcb1 ba8a ...9...a..PH....
> 0x0150: e211 a00d 3c07 71a2 02e3 5d02 0000 5e03 ....<.q...]...^.
> 0x0160: 0102 013c 2050 5845 436c 6965 6e74 3a41 ...<.PXEClient:A
> 0x0170: 7263 683a 3030 3030 303a 554e 4449 3a30 rch:00000:UNDI:0
> 0x0180: 3032 3030 312b 0747 0480 0000 00ff ff00 02001+.G........
> 0x0190: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x01a0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x01b0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x01c0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x01d0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x01e0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x01f0: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0200: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0210: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0220: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0230: 0000 0000 0000 0000 0000 0000 0000 0000 ................
> 0x0240: 0000 0000 0000 0000 0000 0000 0000 ..............
>
>
> Again sorry for not having found some way to decode those packets.
>
> Cheers,
> Alkis
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