Does it matter what UDP port a WOL signal is sent to?
i have seen many WOL instances use port 7 and many use port 9, does it matter?
Isn't it just looking for a WOL packet at layer 2 or ethernet?
ethernet port wake-on-lan udp
asked Jun 10 '11 at 5:52
rjtrjt
64921016
add a comment |
i have seen many WOL instances use port 7 and many use port 9, does it matter?
Isn't it just looking for a WOL packet at layer 2 or ethernet?
ethernet port wake-on-lan udp
asked Jun 10 '11 at 5:52
rjtrjt
64921016
add a comment |
i have seen many WOL instances use port 7 and many use port 9, does it matter?
Isn't it just looking for a WOL packet at layer 2 or ethernet?
ethernet port wake-on-lan udp
asked Jun 10 '11 at 5:52
rjtrjt
64921016
i have seen many WOL instances use port 7 and many use port 9, does it matter?
Isn't it just looking for a WOL packet at layer 2 or ethernet?
ethernet port wake-on-lan udp
ethernet port wake-on-lan udp
asked Jun 10 '11 at 5:52
rjtrjt
64921016
asked Jun 10 '11 at 5:52
rjtrjt
64921016
asked Jun 10 '11 at 5:52
rjtrjt
64921016
asked Jun 10 '11 at 5:52
rjtrjt
64921016
asked Jun 10 '11 at 5:52
rjtrjt
64921016
64921016
add a comment |
add a comment |
3 Answers
3
active
oldest
votes
@Spiff is correct that it doesn't matter as far as the Wake-on-LAN functionality of the intended recipient goes. However, UDP is recommended because it can be generated without raw sockets which come with security restrictions, and port 9 is recommended because it maps to the old well-known discard protocol whereas port 7 maps to the echo protocol.
This means that if there are hosts on your network that support these old simple standard services you will get unnecessary backscatter traffic when using port 7 but none when using port 9. And since Wake-on-LAN is normally broadcasted, you could get backscatter from many hosts.
Further, if you are troubleshooting WoL with a network sniffer such as Wireshark, it will decode WoL packets properly only if they are UDP packets on port 9.
answered Jan 22 '16 at 15:06
WinTakeAllWinTakeAll
361310
2
Thanks, that was informative! Turned out Intel vPro nics discard and ignore WOL packets completely and of course turns out these were vPro machines I was trying to wake.
– rjt
Jan 23 '16 at 1:14
add a comment |
Nope, it doesn't matter. It doesn't even have to be a UDP or an IP packet at all. The NIC is just looking for the magic pattern (six bytes of 0xff, then its own MAC address 16 times) in all the frames it sees.
answered Jun 10 '11 at 7:18
SpiffSpiff
77k10117163
"in all the frames it sees" --- so the 6x0xff + 16xMAC can be in a single frame?
– rjt
Jun 13 '11 at 22:42
@rjt Yes, the magic pattern can be in a single frame. In fact, it probably has to be. I doubt it would work if it was split between frames.
– Spiff
Jun 13 '11 at 22:52
1
So this will even work if you egress the WoL-VLAN tagged toward the end user (if not otherwise possible)?
– Marki
Mar 10 '17 at 9:24
add a comment |
When I woke my computer using port 9 it would restart instead of coming out of sleep. For the life of me I couldn't figure out what I did wrong. I tried using port 7 and instead of restarting it woke up normally. It doesn't seem to matter most of the time which you use, but for my hardware I need to use port 7.
edited Aug 14 '14 at 13:31
gronostaj
28.2k1369107
answered Aug 14 '14 at 13:27
BrandonBrandon
6111
3
for the sake of knowing, what hardware was it that behaved this way? sounds like port 9 was being used as a sort of ILO instead of WOL.
– Shaun Wilson
Dec 3 '16 at 20:28
add a comment |
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3 Answers
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3 Answers
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@Spiff is correct that it doesn't matter as far as the Wake-on-LAN functionality of the intended recipient goes. However, UDP is recommended because it can be generated without raw sockets which come with security restrictions, and port 9 is recommended because it maps to the old well-known discard protocol whereas port 7 maps to the echo protocol.
This means that if there are hosts on your network that support these old simple standard services you will get unnecessary backscatter traffic when using port 7 but none when using port 9. And since Wake-on-LAN is normally broadcasted, you could get backscatter from many hosts.
Further, if you are troubleshooting WoL with a network sniffer such as Wireshark, it will decode WoL packets properly only if they are UDP packets on port 9.
answered Jan 22 '16 at 15:06
WinTakeAllWinTakeAll
361310
2
Thanks, that was informative! Turned out Intel vPro nics discard and ignore WOL packets completely and of course turns out these were vPro machines I was trying to wake.
– rjt
Jan 23 '16 at 1:14
add a comment |
@Spiff is correct that it doesn't matter as far as the Wake-on-LAN functionality of the intended recipient goes. However, UDP is recommended because it can be generated without raw sockets which come with security restrictions, and port 9 is recommended because it maps to the old well-known discard protocol whereas port 7 maps to the echo protocol.
This means that if there are hosts on your network that support these old simple standard services you will get unnecessary backscatter traffic when using port 7 but none when using port 9. And since Wake-on-LAN is normally broadcasted, you could get backscatter from many hosts.
Further, if you are troubleshooting WoL with a network sniffer such as Wireshark, it will decode WoL packets properly only if they are UDP packets on port 9.
answered Jan 22 '16 at 15:06
WinTakeAllWinTakeAll
361310
2
Thanks, that was informative! Turned out Intel vPro nics discard and ignore WOL packets completely and of course turns out these were vPro machines I was trying to wake.
– rjt
Jan 23 '16 at 1:14
add a comment |
@Spiff is correct that it doesn't matter as far as the Wake-on-LAN functionality of the intended recipient goes. However, UDP is recommended because it can be generated without raw sockets which come with security restrictions, and port 9 is recommended because it maps to the old well-known discard protocol whereas port 7 maps to the echo protocol.
This means that if there are hosts on your network that support these old simple standard services you will get unnecessary backscatter traffic when using port 7 but none when using port 9. And since Wake-on-LAN is normally broadcasted, you could get backscatter from many hosts.
Further, if you are troubleshooting WoL with a network sniffer such as Wireshark, it will decode WoL packets properly only if they are UDP packets on port 9.
answered Jan 22 '16 at 15:06
WinTakeAllWinTakeAll
361310
@Spiff is correct that it doesn't matter as far as the Wake-on-LAN functionality of the intended recipient goes. However, UDP is recommended because it can be generated without raw sockets which come with security restrictions, and port 9 is recommended because it maps to the old well-known discard protocol whereas port 7 maps to the echo protocol.
This means that if there are hosts on your network that support these old simple standard services you will get unnecessary backscatter traffic when using port 7 but none when using port 9. And since Wake-on-LAN is normally broadcasted, you could get backscatter from many hosts.
Further, if you are troubleshooting WoL with a network sniffer such as Wireshark, it will decode WoL packets properly only if they are UDP packets on port 9.
answered Jan 22 '16 at 15:06
WinTakeAllWinTakeAll
361310
edited Feb 17 '16 at 10:21
answered Jan 22 '16 at 15:06
WinTakeAllWinTakeAll
361310
answered Jan 22 '16 at 15:06
WinTakeAllWinTakeAll
361310
answered Jan 22 '16 at 15:06
WinTakeAllWinTakeAll
361310
361310
2
Thanks, that was informative! Turned out Intel vPro nics discard and ignore WOL packets completely and of course turns out these were vPro machines I was trying to wake.
– rjt
Jan 23 '16 at 1:14
add a comment |
2
Thanks, that was informative! Turned out Intel vPro nics discard and ignore WOL packets completely and of course turns out these were vPro machines I was trying to wake.
– rjt
Jan 23 '16 at 1:14
2
2
Thanks, that was informative! Turned out Intel vPro nics discard and ignore WOL packets completely and of course turns out these were vPro machines I was trying to wake.
– rjt
Jan 23 '16 at 1:14
Thanks, that was informative! Turned out Intel vPro nics discard and ignore WOL packets completely and of course turns out these were vPro machines I was trying to wake.
– rjt
Jan 23 '16 at 1:14
add a comment |
Nope, it doesn't matter. It doesn't even have to be a UDP or an IP packet at all. The NIC is just looking for the magic pattern (six bytes of 0xff, then its own MAC address 16 times) in all the frames it sees.
answered Jun 10 '11 at 7:18
SpiffSpiff
77k10117163
"in all the frames it sees" --- so the 6x0xff + 16xMAC can be in a single frame?
– rjt
Jun 13 '11 at 22:42
@rjt Yes, the magic pattern can be in a single frame. In fact, it probably has to be. I doubt it would work if it was split between frames.
– Spiff
Jun 13 '11 at 22:52
1
So this will even work if you egress the WoL-VLAN tagged toward the end user (if not otherwise possible)?
– Marki
Mar 10 '17 at 9:24
add a comment |
Nope, it doesn't matter. It doesn't even have to be a UDP or an IP packet at all. The NIC is just looking for the magic pattern (six bytes of 0xff, then its own MAC address 16 times) in all the frames it sees.
answered Jun 10 '11 at 7:18
SpiffSpiff
77k10117163
"in all the frames it sees" --- so the 6x0xff + 16xMAC can be in a single frame?
– rjt
Jun 13 '11 at 22:42
@rjt Yes, the magic pattern can be in a single frame. In fact, it probably has to be. I doubt it would work if it was split between frames.
– Spiff
Jun 13 '11 at 22:52
1
So this will even work if you egress the WoL-VLAN tagged toward the end user (if not otherwise possible)?
– Marki
Mar 10 '17 at 9:24
add a comment |
Nope, it doesn't matter. It doesn't even have to be a UDP or an IP packet at all. The NIC is just looking for the magic pattern (six bytes of 0xff, then its own MAC address 16 times) in all the frames it sees.
answered Jun 10 '11 at 7:18
SpiffSpiff
77k10117163
Nope, it doesn't matter. It doesn't even have to be a UDP or an IP packet at all. The NIC is just looking for the magic pattern (six bytes of 0xff, then its own MAC address 16 times) in all the frames it sees.
answered Jun 10 '11 at 7:18
SpiffSpiff
77k10117163
answered Jun 10 '11 at 7:18
SpiffSpiff
77k10117163
answered Jun 10 '11 at 7:18
SpiffSpiff
77k10117163
answered Jun 10 '11 at 7:18
SpiffSpiff
77k10117163
77k10117163
"in all the frames it sees" --- so the 6x0xff + 16xMAC can be in a single frame?
– rjt
Jun 13 '11 at 22:42
@rjt Yes, the magic pattern can be in a single frame. In fact, it probably has to be. I doubt it would work if it was split between frames.
– Spiff
Jun 13 '11 at 22:52
1
So this will even work if you egress the WoL-VLAN tagged toward the end user (if not otherwise possible)?
– Marki
Mar 10 '17 at 9:24
add a comment |
"in all the frames it sees" --- so the 6x0xff + 16xMAC can be in a single frame?
– rjt
Jun 13 '11 at 22:42
@rjt Yes, the magic pattern can be in a single frame. In fact, it probably has to be. I doubt it would work if it was split between frames.
– Spiff
Jun 13 '11 at 22:52
1
So this will even work if you egress the WoL-VLAN tagged toward the end user (if not otherwise possible)?
– Marki
Mar 10 '17 at 9:24
"in all the frames it sees" --- so the 6x0xff + 16xMAC can be in a single frame?
– rjt
Jun 13 '11 at 22:42
"in all the frames it sees" --- so the 6x0xff + 16xMAC can be in a single frame?
– rjt
Jun 13 '11 at 22:42
@rjt Yes, the magic pattern can be in a single frame. In fact, it probably has to be. I doubt it would work if it was split between frames.
– Spiff
Jun 13 '11 at 22:52
@rjt Yes, the magic pattern can be in a single frame. In fact, it probably has to be. I doubt it would work if it was split between frames.
– Spiff
Jun 13 '11 at 22:52
1
1
So this will even work if you egress the WoL-VLAN tagged toward the end user (if not otherwise possible)?
– Marki
Mar 10 '17 at 9:24
So this will even work if you egress the WoL-VLAN tagged toward the end user (if not otherwise possible)?
– Marki
Mar 10 '17 at 9:24
add a comment |
When I woke my computer using port 9 it would restart instead of coming out of sleep. For the life of me I couldn't figure out what I did wrong. I tried using port 7 and instead of restarting it woke up normally. It doesn't seem to matter most of the time which you use, but for my hardware I need to use port 7.
edited Aug 14 '14 at 13:31
gronostaj
28.2k1369107
answered Aug 14 '14 at 13:27
BrandonBrandon
6111
3
for the sake of knowing, what hardware was it that behaved this way? sounds like port 9 was being used as a sort of ILO instead of WOL.
– Shaun Wilson
Dec 3 '16 at 20:28
add a comment |
When I woke my computer using port 9 it would restart instead of coming out of sleep. For the life of me I couldn't figure out what I did wrong. I tried using port 7 and instead of restarting it woke up normally. It doesn't seem to matter most of the time which you use, but for my hardware I need to use port 7.
edited Aug 14 '14 at 13:31
gronostaj
28.2k1369107
answered Aug 14 '14 at 13:27
BrandonBrandon
6111
3
for the sake of knowing, what hardware was it that behaved this way? sounds like port 9 was being used as a sort of ILO instead of WOL.
– Shaun Wilson
Dec 3 '16 at 20:28
add a comment |
When I woke my computer using port 9 it would restart instead of coming out of sleep. For the life of me I couldn't figure out what I did wrong. I tried using port 7 and instead of restarting it woke up normally. It doesn't seem to matter most of the time which you use, but for my hardware I need to use port 7.
edited Aug 14 '14 at 13:31
gronostaj
28.2k1369107
answered Aug 14 '14 at 13:27
BrandonBrandon
6111
When I woke my computer using port 9 it would restart instead of coming out of sleep. For the life of me I couldn't figure out what I did wrong. I tried using port 7 and instead of restarting it woke up normally. It doesn't seem to matter most of the time which you use, but for my hardware I need to use port 7.
edited Aug 14 '14 at 13:31
gronostaj
28.2k1369107
answered Aug 14 '14 at 13:27
BrandonBrandon
6111
edited Aug 14 '14 at 13:31
gronostaj
28.2k1369107
edited Aug 14 '14 at 13:31
gronostaj
28.2k1369107
edited Aug 14 '14 at 13:31
gronostaj
28.2k1369107
28.2k1369107
answered Aug 14 '14 at 13:27
BrandonBrandon
6111
answered Aug 14 '14 at 13:27
BrandonBrandon
6111
answered Aug 14 '14 at 13:27
BrandonBrandon
6111
6111
3
for the sake of knowing, what hardware was it that behaved this way? sounds like port 9 was being used as a sort of ILO instead of WOL.
– Shaun Wilson
Dec 3 '16 at 20:28
add a comment |
3
for the sake of knowing, what hardware was it that behaved this way? sounds like port 9 was being used as a sort of ILO instead of WOL.
– Shaun Wilson
Dec 3 '16 at 20:28
3
3
for the sake of knowing, what hardware was it that behaved this way? sounds like port 9 was being used as a sort of ILO instead of WOL.
– Shaun Wilson
Dec 3 '16 at 20:28
for the sake of knowing, what hardware was it that behaved this way? sounds like port 9 was being used as a sort of ILO instead of WOL.
– Shaun Wilson
Dec 3 '16 at 20:28
add a comment |
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