Mixing
Crossover cable or straight through between multiple hubs/switches
Clash Royale CLAN TAG#URR8PPP
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I'm networking a bunch of Raspberry Pis together on a subnet as shown in my highly technical diagram below:
I'm wondering if the red cables are supposed to be crossover cables or straight through? The blue cables I'm quite sure are supposed to be straight through cables (but please correct if I'm wrong).
Also what if I were to swap out any of the hubs for switches, would that change whether I should be using crossover vs. straight through cabling anywhere?
Thank you
networking ethernet switch hub crossover-cable
asked yesterday
Matt
1138
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 |Â
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up vote
13
down vote
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I'm networking a bunch of Raspberry Pis together on a subnet as shown in my highly technical diagram below:
I'm wondering if the red cables are supposed to be crossover cables or straight through? The blue cables I'm quite sure are supposed to be straight through cables (but please correct if I'm wrong).
Also what if I were to swap out any of the hubs for switches, would that change whether I should be using crossover vs. straight through cabling anywhere?
Thank you
networking ethernet switch hub crossover-cable
asked yesterday
Matt
1138
New contributor
Matt is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Is it a semi-permanent setup with cables in walls etc? Or just a bunch of devices on a table? If latter, I would use any good cables and count on Auto MDI-X. Or do you deliberately want/need to allow hubs without this feature?
– Kamil Maciorowski
yesterday
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check? The setup does not have cabling in walls but it still needs to be permanent and reliable as it won't be me operating it and so I won't be on hand to fix any issues with cabling
– Matt
yesterday
@Matt Can you link us to the product page? I'd hope they're not actual hubs - the distinction is very important.
– Bob
yesterday
@Bob I went to go double check the page here ... I missed the part that said switch
– Matt
yesterday
1
It's definitely a switch, and the description below in that page actually explicitly mentions Auto-MDI/MDIX support, among various other switch-only features. (Slightly odd that the same page also says "Communication mode: Half-duplex" as opposed to full-duplex, but I guess they just copy-pasted whatever.)
– grawity
yesterday
 |Â
show 1 more comment
up vote
13
down vote
favorite
up vote
13
down vote
favorite
I'm networking a bunch of Raspberry Pis together on a subnet as shown in my highly technical diagram below:
I'm wondering if the red cables are supposed to be crossover cables or straight through? The blue cables I'm quite sure are supposed to be straight through cables (but please correct if I'm wrong).
Also what if I were to swap out any of the hubs for switches, would that change whether I should be using crossover vs. straight through cabling anywhere?
Thank you
networking ethernet switch hub crossover-cable
asked yesterday
Matt
1138
New contributor
Matt is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I'm networking a bunch of Raspberry Pis together on a subnet as shown in my highly technical diagram below:
I'm wondering if the red cables are supposed to be crossover cables or straight through? The blue cables I'm quite sure are supposed to be straight through cables (but please correct if I'm wrong).
Also what if I were to swap out any of the hubs for switches, would that change whether I should be using crossover vs. straight through cabling anywhere?
Thank you
networking ethernet switch hub crossover-cable
networking ethernet switch hub crossover-cable
asked yesterday
Matt
1138
New contributor
Matt is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
Matt
1138
New contributor
Matt is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
Matt
1138
New contributor
Matt is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
Matt
1138
asked yesterday
Matt
1138
1138
New contributor
Matt is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Matt is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Matt is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Is it a semi-permanent setup with cables in walls etc? Or just a bunch of devices on a table? If latter, I would use any good cables and count on Auto MDI-X. Or do you deliberately want/need to allow hubs without this feature?
– Kamil Maciorowski
yesterday
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check? The setup does not have cabling in walls but it still needs to be permanent and reliable as it won't be me operating it and so I won't be on hand to fix any issues with cabling
– Matt
yesterday
@Matt Can you link us to the product page? I'd hope they're not actual hubs - the distinction is very important.
– Bob
yesterday
@Bob I went to go double check the page here ... I missed the part that said switch
– Matt
yesterday
1
It's definitely a switch, and the description below in that page actually explicitly mentions Auto-MDI/MDIX support, among various other switch-only features. (Slightly odd that the same page also says "Communication mode: Half-duplex" as opposed to full-duplex, but I guess they just copy-pasted whatever.)
– grawity
yesterday
 |Â
show 1 more comment
Is it a semi-permanent setup with cables in walls etc? Or just a bunch of devices on a table? If latter, I would use any good cables and count on Auto MDI-X. Or do you deliberately want/need to allow hubs without this feature?
– Kamil Maciorowski
yesterday
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check? The setup does not have cabling in walls but it still needs to be permanent and reliable as it won't be me operating it and so I won't be on hand to fix any issues with cabling
– Matt
yesterday
@Matt Can you link us to the product page? I'd hope they're not actual hubs - the distinction is very important.
– Bob
yesterday
@Bob I went to go double check the page here ... I missed the part that said switch
– Matt
yesterday
1
It's definitely a switch, and the description below in that page actually explicitly mentions Auto-MDI/MDIX support, among various other switch-only features. (Slightly odd that the same page also says "Communication mode: Half-duplex" as opposed to full-duplex, but I guess they just copy-pasted whatever.)
– grawity
yesterday
Is it a semi-permanent setup with cables in walls etc? Or just a bunch of devices on a table? If latter, I would use any good cables and count on Auto MDI-X. Or do you deliberately want/need to allow hubs without this feature?
– Kamil Maciorowski
yesterday
Is it a semi-permanent setup with cables in walls etc? Or just a bunch of devices on a table? If latter, I would use any good cables and count on Auto MDI-X. Or do you deliberately want/need to allow hubs without this feature?
– Kamil Maciorowski
yesterday
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check? The setup does not have cabling in walls but it still needs to be permanent and reliable as it won't be me operating it and so I won't be on hand to fix any issues with cabling
– Matt
yesterday
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check? The setup does not have cabling in walls but it still needs to be permanent and reliable as it won't be me operating it and so I won't be on hand to fix any issues with cabling
– Matt
yesterday
@Matt Can you link us to the product page? I'd hope they're not actual hubs - the distinction is very important.
– Bob
yesterday
@Matt Can you link us to the product page? I'd hope they're not actual hubs - the distinction is very important.
– Bob
yesterday
@Bob I went to go double check the page here ... I missed the part that said switch
– Matt
yesterday
@Bob I went to go double check the page here ... I missed the part that said switch
– Matt
yesterday
1
1
It's definitely a switch, and the description below in that page actually explicitly mentions Auto-MDI/MDIX support, among various other switch-only features. (Slightly odd that the same page also says "Communication mode: Half-duplex" as opposed to full-duplex, but I guess they just copy-pasted whatever.)
– grawity
yesterday
It's definitely a switch, and the description below in that page actually explicitly mentions Auto-MDI/MDIX support, among various other switch-only features. (Slightly odd that the same page also says "Communication mode: Half-duplex" as opposed to full-duplex, but I guess they just copy-pasted whatever.)
– grawity
yesterday
 |Â
show 1 more comment
2 Answers
2
active
oldest
votes
up vote
33
down vote
accepted
Most modern hardware – Ethernet switches and computer Ethernet interfaces – implements Auto-MDIX, automatically choosing the correct mode for each physical connection. (This is now a required part of Gigabit Ethernet, but also very common among 100 Mbps ports as well.) In other words, you can use the same type – regular straight-through cables – practically everywhere.
Ethernet hubs, however, do not have this feature. They do not participate in link negotiation and only electrically connect all the devices. (Although your devices are probably switches mislabelled as hubs, not actual hubs.)
Without this feature, two hubs or switches (just like two computers) would have needed a cross-over cable. That is, unless one switch had a dedicated 'Uplink' port, which would accept a straight-through cable instead. (Sometimes the last port had a physical toggle button for this.)
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check?
The easiest way to find out whether it works is to connect all the devices together and see whether the 'link' indicator lights turn on on both ends, and whether you can actually send/receive packets between them. If it works, that means it works. (Ethernet ports are transformer-isolated, which I think means that you won't physically damage anything by just using the wrong kind of cable.)
Other indications:
- If they are 1 Gbps switches, then at least the 1G ports will always have Auto-MDIX.
- If the specs mention "Auto-Uplink", that's just another name for Auto-MDIX, so you're good.
- If the specs mention "store and forward", that at least means you have a switch.
Note: do not buy actual hubs. You won't get any reasonable performance out of a hub (getting worse the more devices you have), and you will never have 1 Gbps support in a hub. (And they're not any cheaper than switches anymore.)
That said, what you bought is quite likely to be switches mislabeled as hubs, but be careful regardless. I mean, "super cheap" usually contradicts "permanent and reliable".
answered yesterday
grawity
216k32436505
Very well explained, thank you. One follow up question - so because my so called 'hubs' do not have a dedicated 'uplink' port and I have successfully connected two computers to one another through that hub using straight through cabling only, that should confirm that the hub is actually a switch, correct?
– Matt
yesterday
1
@Matt: I'm not sure if it's a guarantee (try connecting at least 3 devices). But it's very likely to be a switch – because switches are so widespread that they almost became cheaper to make than hubs, while at the same time offering much better performance than hubs.
– grawity
yesterday
4
@matt You can test if its a hub vs switch by connecting at least 3 devices, and then sending a large file from PC 1 to PC 2, if the activity light on all pc's blink at the same rate, its a hub, if the activity on only 2 of the pc's blink in sync, it's a switch
– Ferrybig
yesterday
@Ferrybig great point. Thanks for adding that!
– Matt
yesterday
1
"hubs" do not "electrically connect all the devices together" (they decode and re-generate the signal, but do so in real time without buffering). There is no technical reason a hub could not support auto-MDIx through in practice they generally don't..
– plugwash
20 hours ago
 |Â
show 2 more comments
up vote
7
down vote
Technically speaking, cross over cables are supposed to be used when connecting devices of the same “type†together. Like connecting 2 PCs together, or 2 switches together.
When connecting devices of different types together you use a straight through cable. Like when plugging a PC into a switch.
There are really only two different “types†of devices. A NIC in PC configuration and a NIC in router/switch/hub configuration.
For network communications to occur the transmit line on one end needs to connect to the receive line on the other end and vice-versa. The two types of devices use opposite transmit/receive pinout configurations and a straight-through cable is used to connect them. But when connecting the same interface type together a cross-over cable is necessary.
However, that is all technically speaking. In reality, Auto MDI-X has existed for 20 years and is included pretty much on every network interface that exists nowadays. The need for a cross-over cable is very rare, and is not likely necessary in your situation. This feature may also be called Auto uplink and trade, Universal Cable Recognition and Auto Sensing.
answered yesterday
Appleoddity
6,29021024
1
Part of why Auto-MDIX is practically everywhere is because 1000BASE-T no longer has separate transmit and receive lines. (All four pairs are bidirectional.)
– grawity
yesterday
Nit-pick - default router ports typically are in "PC configuration". I would change your 3rd paragraph to There are really only two different “modes†of ports. A port in host mode (e.g. PC, router) and a port in switch/hub mode.
– Digital Trauma
11 hours ago
@digitaltrauma ok. I’m not disagreeing, but do you have a reference on that regarding the default port mode?
– Appleoddity
9 hours ago
add a comment |Â
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
33
down vote
accepted
Most modern hardware – Ethernet switches and computer Ethernet interfaces – implements Auto-MDIX, automatically choosing the correct mode for each physical connection. (This is now a required part of Gigabit Ethernet, but also very common among 100 Mbps ports as well.) In other words, you can use the same type – regular straight-through cables – practically everywhere.
Ethernet hubs, however, do not have this feature. They do not participate in link negotiation and only electrically connect all the devices. (Although your devices are probably switches mislabelled as hubs, not actual hubs.)
Without this feature, two hubs or switches (just like two computers) would have needed a cross-over cable. That is, unless one switch had a dedicated 'Uplink' port, which would accept a straight-through cable instead. (Sometimes the last port had a physical toggle button for this.)
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check?
The easiest way to find out whether it works is to connect all the devices together and see whether the 'link' indicator lights turn on on both ends, and whether you can actually send/receive packets between them. If it works, that means it works. (Ethernet ports are transformer-isolated, which I think means that you won't physically damage anything by just using the wrong kind of cable.)
Other indications:
- If they are 1 Gbps switches, then at least the 1G ports will always have Auto-MDIX.
- If the specs mention "Auto-Uplink", that's just another name for Auto-MDIX, so you're good.
- If the specs mention "store and forward", that at least means you have a switch.
Note: do not buy actual hubs. You won't get any reasonable performance out of a hub (getting worse the more devices you have), and you will never have 1 Gbps support in a hub. (And they're not any cheaper than switches anymore.)
That said, what you bought is quite likely to be switches mislabeled as hubs, but be careful regardless. I mean, "super cheap" usually contradicts "permanent and reliable".
answered yesterday
grawity
216k32436505
Very well explained, thank you. One follow up question - so because my so called 'hubs' do not have a dedicated 'uplink' port and I have successfully connected two computers to one another through that hub using straight through cabling only, that should confirm that the hub is actually a switch, correct?
– Matt
yesterday
1
@Matt: I'm not sure if it's a guarantee (try connecting at least 3 devices). But it's very likely to be a switch – because switches are so widespread that they almost became cheaper to make than hubs, while at the same time offering much better performance than hubs.
– grawity
yesterday
4
@matt You can test if its a hub vs switch by connecting at least 3 devices, and then sending a large file from PC 1 to PC 2, if the activity light on all pc's blink at the same rate, its a hub, if the activity on only 2 of the pc's blink in sync, it's a switch
– Ferrybig
yesterday
@Ferrybig great point. Thanks for adding that!
– Matt
yesterday
1
"hubs" do not "electrically connect all the devices together" (they decode and re-generate the signal, but do so in real time without buffering). There is no technical reason a hub could not support auto-MDIx through in practice they generally don't..
– plugwash
20 hours ago
 |Â
show 2 more comments
up vote
33
down vote
accepted
Most modern hardware – Ethernet switches and computer Ethernet interfaces – implements Auto-MDIX, automatically choosing the correct mode for each physical connection. (This is now a required part of Gigabit Ethernet, but also very common among 100 Mbps ports as well.) In other words, you can use the same type – regular straight-through cables – practically everywhere.
Ethernet hubs, however, do not have this feature. They do not participate in link negotiation and only electrically connect all the devices. (Although your devices are probably switches mislabelled as hubs, not actual hubs.)
Without this feature, two hubs or switches (just like two computers) would have needed a cross-over cable. That is, unless one switch had a dedicated 'Uplink' port, which would accept a straight-through cable instead. (Sometimes the last port had a physical toggle button for this.)
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check?
The easiest way to find out whether it works is to connect all the devices together and see whether the 'link' indicator lights turn on on both ends, and whether you can actually send/receive packets between them. If it works, that means it works. (Ethernet ports are transformer-isolated, which I think means that you won't physically damage anything by just using the wrong kind of cable.)
Other indications:
- If they are 1 Gbps switches, then at least the 1G ports will always have Auto-MDIX.
- If the specs mention "Auto-Uplink", that's just another name for Auto-MDIX, so you're good.
- If the specs mention "store and forward", that at least means you have a switch.
Note: do not buy actual hubs. You won't get any reasonable performance out of a hub (getting worse the more devices you have), and you will never have 1 Gbps support in a hub. (And they're not any cheaper than switches anymore.)
That said, what you bought is quite likely to be switches mislabeled as hubs, but be careful regardless. I mean, "super cheap" usually contradicts "permanent and reliable".
answered yesterday
grawity
216k32436505
Very well explained, thank you. One follow up question - so because my so called 'hubs' do not have a dedicated 'uplink' port and I have successfully connected two computers to one another through that hub using straight through cabling only, that should confirm that the hub is actually a switch, correct?
– Matt
yesterday
1
@Matt: I'm not sure if it's a guarantee (try connecting at least 3 devices). But it's very likely to be a switch – because switches are so widespread that they almost became cheaper to make than hubs, while at the same time offering much better performance than hubs.
– grawity
yesterday
4
@matt You can test if its a hub vs switch by connecting at least 3 devices, and then sending a large file from PC 1 to PC 2, if the activity light on all pc's blink at the same rate, its a hub, if the activity on only 2 of the pc's blink in sync, it's a switch
– Ferrybig
yesterday
@Ferrybig great point. Thanks for adding that!
– Matt
yesterday
1
"hubs" do not "electrically connect all the devices together" (they decode and re-generate the signal, but do so in real time without buffering). There is no technical reason a hub could not support auto-MDIx through in practice they generally don't..
– plugwash
20 hours ago
 |Â
show 2 more comments
up vote
33
down vote
accepted
up vote
33
down vote
accepted
Most modern hardware – Ethernet switches and computer Ethernet interfaces – implements Auto-MDIX, automatically choosing the correct mode for each physical connection. (This is now a required part of Gigabit Ethernet, but also very common among 100 Mbps ports as well.) In other words, you can use the same type – regular straight-through cables – practically everywhere.
Ethernet hubs, however, do not have this feature. They do not participate in link negotiation and only electrically connect all the devices. (Although your devices are probably switches mislabelled as hubs, not actual hubs.)
Without this feature, two hubs or switches (just like two computers) would have needed a cross-over cable. That is, unless one switch had a dedicated 'Uplink' port, which would accept a straight-through cable instead. (Sometimes the last port had a physical toggle button for this.)
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check?
The easiest way to find out whether it works is to connect all the devices together and see whether the 'link' indicator lights turn on on both ends, and whether you can actually send/receive packets between them. If it works, that means it works. (Ethernet ports are transformer-isolated, which I think means that you won't physically damage anything by just using the wrong kind of cable.)
Other indications:
- If they are 1 Gbps switches, then at least the 1G ports will always have Auto-MDIX.
- If the specs mention "Auto-Uplink", that's just another name for Auto-MDIX, so you're good.
- If the specs mention "store and forward", that at least means you have a switch.
Note: do not buy actual hubs. You won't get any reasonable performance out of a hub (getting worse the more devices you have), and you will never have 1 Gbps support in a hub. (And they're not any cheaper than switches anymore.)
That said, what you bought is quite likely to be switches mislabeled as hubs, but be careful regardless. I mean, "super cheap" usually contradicts "permanent and reliable".
answered yesterday
grawity
216k32436505
Most modern hardware – Ethernet switches and computer Ethernet interfaces – implements Auto-MDIX, automatically choosing the correct mode for each physical connection. (This is now a required part of Gigabit Ethernet, but also very common among 100 Mbps ports as well.) In other words, you can use the same type – regular straight-through cables – practically everywhere.
Ethernet hubs, however, do not have this feature. They do not participate in link negotiation and only electrically connect all the devices. (Although your devices are probably switches mislabelled as hubs, not actual hubs.)
Without this feature, two hubs or switches (just like two computers) would have needed a cross-over cable. That is, unless one switch had a dedicated 'Uplink' port, which would accept a straight-through cable instead. (Sometimes the last port had a physical toggle button for this.)
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check?
The easiest way to find out whether it works is to connect all the devices together and see whether the 'link' indicator lights turn on on both ends, and whether you can actually send/receive packets between them. If it works, that means it works. (Ethernet ports are transformer-isolated, which I think means that you won't physically damage anything by just using the wrong kind of cable.)
Other indications:
- If they are 1 Gbps switches, then at least the 1G ports will always have Auto-MDIX.
- If the specs mention "Auto-Uplink", that's just another name for Auto-MDIX, so you're good.
- If the specs mention "store and forward", that at least means you have a switch.
Note: do not buy actual hubs. You won't get any reasonable performance out of a hub (getting worse the more devices you have), and you will never have 1 Gbps support in a hub. (And they're not any cheaper than switches anymore.)
That said, what you bought is quite likely to be switches mislabeled as hubs, but be careful regardless. I mean, "super cheap" usually contradicts "permanent and reliable".
answered yesterday
grawity
216k32436505
edited yesterday
answered yesterday
grawity
216k32436505
answered yesterday
grawity
216k32436505
answered yesterday
grawity
216k32436505
216k32436505
Very well explained, thank you. One follow up question - so because my so called 'hubs' do not have a dedicated 'uplink' port and I have successfully connected two computers to one another through that hub using straight through cabling only, that should confirm that the hub is actually a switch, correct?
– Matt
yesterday
1
@Matt: I'm not sure if it's a guarantee (try connecting at least 3 devices). But it's very likely to be a switch – because switches are so widespread that they almost became cheaper to make than hubs, while at the same time offering much better performance than hubs.
– grawity
yesterday
4
@matt You can test if its a hub vs switch by connecting at least 3 devices, and then sending a large file from PC 1 to PC 2, if the activity light on all pc's blink at the same rate, its a hub, if the activity on only 2 of the pc's blink in sync, it's a switch
– Ferrybig
yesterday
@Ferrybig great point. Thanks for adding that!
– Matt
yesterday
1
"hubs" do not "electrically connect all the devices together" (they decode and re-generate the signal, but do so in real time without buffering). There is no technical reason a hub could not support auto-MDIx through in practice they generally don't..
– plugwash
20 hours ago
 |Â
show 2 more comments
Very well explained, thank you. One follow up question - so because my so called 'hubs' do not have a dedicated 'uplink' port and I have successfully connected two computers to one another through that hub using straight through cabling only, that should confirm that the hub is actually a switch, correct?
– Matt
yesterday
1
@Matt: I'm not sure if it's a guarantee (try connecting at least 3 devices). But it's very likely to be a switch – because switches are so widespread that they almost became cheaper to make than hubs, while at the same time offering much better performance than hubs.
– grawity
yesterday
4
@matt You can test if its a hub vs switch by connecting at least 3 devices, and then sending a large file from PC 1 to PC 2, if the activity light on all pc's blink at the same rate, its a hub, if the activity on only 2 of the pc's blink in sync, it's a switch
– Ferrybig
yesterday
@Ferrybig great point. Thanks for adding that!
– Matt
yesterday
1
"hubs" do not "electrically connect all the devices together" (they decode and re-generate the signal, but do so in real time without buffering). There is no technical reason a hub could not support auto-MDIx through in practice they generally don't..
– plugwash
20 hours ago
Very well explained, thank you. One follow up question - so because my so called 'hubs' do not have a dedicated 'uplink' port and I have successfully connected two computers to one another through that hub using straight through cabling only, that should confirm that the hub is actually a switch, correct?
– Matt
yesterday
Very well explained, thank you. One follow up question - so because my so called 'hubs' do not have a dedicated 'uplink' port and I have successfully connected two computers to one another through that hub using straight through cabling only, that should confirm that the hub is actually a switch, correct?
– Matt
yesterday
1
1
@Matt: I'm not sure if it's a guarantee (try connecting at least 3 devices). But it's very likely to be a switch – because switches are so widespread that they almost became cheaper to make than hubs, while at the same time offering much better performance than hubs.
– grawity
yesterday
@Matt: I'm not sure if it's a guarantee (try connecting at least 3 devices). But it's very likely to be a switch – because switches are so widespread that they almost became cheaper to make than hubs, while at the same time offering much better performance than hubs.
– grawity
yesterday
4
4
@matt You can test if its a hub vs switch by connecting at least 3 devices, and then sending a large file from PC 1 to PC 2, if the activity light on all pc's blink at the same rate, its a hub, if the activity on only 2 of the pc's blink in sync, it's a switch
– Ferrybig
yesterday
@matt You can test if its a hub vs switch by connecting at least 3 devices, and then sending a large file from PC 1 to PC 2, if the activity light on all pc's blink at the same rate, its a hub, if the activity on only 2 of the pc's blink in sync, it's a switch
– Ferrybig
yesterday
@Ferrybig great point. Thanks for adding that!
– Matt
yesterday
@Ferrybig great point. Thanks for adding that!
– Matt
yesterday
1
1
"hubs" do not "electrically connect all the devices together" (they decode and re-generate the signal, but do so in real time without buffering). There is no technical reason a hub could not support auto-MDIx through in practice they generally don't..
– plugwash
20 hours ago
"hubs" do not "electrically connect all the devices together" (they decode and re-generate the signal, but do so in real time without buffering). There is no technical reason a hub could not support auto-MDIx through in practice they generally don't..
– plugwash
20 hours ago
 |Â
show 2 more comments
up vote
7
down vote
Technically speaking, cross over cables are supposed to be used when connecting devices of the same “type†together. Like connecting 2 PCs together, or 2 switches together.
When connecting devices of different types together you use a straight through cable. Like when plugging a PC into a switch.
There are really only two different “types†of devices. A NIC in PC configuration and a NIC in router/switch/hub configuration.
For network communications to occur the transmit line on one end needs to connect to the receive line on the other end and vice-versa. The two types of devices use opposite transmit/receive pinout configurations and a straight-through cable is used to connect them. But when connecting the same interface type together a cross-over cable is necessary.
However, that is all technically speaking. In reality, Auto MDI-X has existed for 20 years and is included pretty much on every network interface that exists nowadays. The need for a cross-over cable is very rare, and is not likely necessary in your situation. This feature may also be called Auto uplink and trade, Universal Cable Recognition and Auto Sensing.
answered yesterday
Appleoddity
6,29021024
1
Part of why Auto-MDIX is practically everywhere is because 1000BASE-T no longer has separate transmit and receive lines. (All four pairs are bidirectional.)
– grawity
yesterday
Nit-pick - default router ports typically are in "PC configuration". I would change your 3rd paragraph to There are really only two different “modes†of ports. A port in host mode (e.g. PC, router) and a port in switch/hub mode.
– Digital Trauma
11 hours ago
@digitaltrauma ok. I’m not disagreeing, but do you have a reference on that regarding the default port mode?
– Appleoddity
9 hours ago
add a comment |Â
up vote
7
down vote
Technically speaking, cross over cables are supposed to be used when connecting devices of the same “type†together. Like connecting 2 PCs together, or 2 switches together.
When connecting devices of different types together you use a straight through cable. Like when plugging a PC into a switch.
There are really only two different “types†of devices. A NIC in PC configuration and a NIC in router/switch/hub configuration.
For network communications to occur the transmit line on one end needs to connect to the receive line on the other end and vice-versa. The two types of devices use opposite transmit/receive pinout configurations and a straight-through cable is used to connect them. But when connecting the same interface type together a cross-over cable is necessary.
However, that is all technically speaking. In reality, Auto MDI-X has existed for 20 years and is included pretty much on every network interface that exists nowadays. The need for a cross-over cable is very rare, and is not likely necessary in your situation. This feature may also be called Auto uplink and trade, Universal Cable Recognition and Auto Sensing.
answered yesterday
Appleoddity
6,29021024
1
Part of why Auto-MDIX is practically everywhere is because 1000BASE-T no longer has separate transmit and receive lines. (All four pairs are bidirectional.)
– grawity
yesterday
Nit-pick - default router ports typically are in "PC configuration". I would change your 3rd paragraph to There are really only two different “modes†of ports. A port in host mode (e.g. PC, router) and a port in switch/hub mode.
– Digital Trauma
11 hours ago
@digitaltrauma ok. I’m not disagreeing, but do you have a reference on that regarding the default port mode?
– Appleoddity
9 hours ago
add a comment |Â
up vote
7
down vote
up vote
7
down vote
Technically speaking, cross over cables are supposed to be used when connecting devices of the same “type†together. Like connecting 2 PCs together, or 2 switches together.
When connecting devices of different types together you use a straight through cable. Like when plugging a PC into a switch.
There are really only two different “types†of devices. A NIC in PC configuration and a NIC in router/switch/hub configuration.
For network communications to occur the transmit line on one end needs to connect to the receive line on the other end and vice-versa. The two types of devices use opposite transmit/receive pinout configurations and a straight-through cable is used to connect them. But when connecting the same interface type together a cross-over cable is necessary.
However, that is all technically speaking. In reality, Auto MDI-X has existed for 20 years and is included pretty much on every network interface that exists nowadays. The need for a cross-over cable is very rare, and is not likely necessary in your situation. This feature may also be called Auto uplink and trade, Universal Cable Recognition and Auto Sensing.
answered yesterday
Appleoddity
6,29021024
Technically speaking, cross over cables are supposed to be used when connecting devices of the same “type†together. Like connecting 2 PCs together, or 2 switches together.
When connecting devices of different types together you use a straight through cable. Like when plugging a PC into a switch.
There are really only two different “types†of devices. A NIC in PC configuration and a NIC in router/switch/hub configuration.
For network communications to occur the transmit line on one end needs to connect to the receive line on the other end and vice-versa. The two types of devices use opposite transmit/receive pinout configurations and a straight-through cable is used to connect them. But when connecting the same interface type together a cross-over cable is necessary.
However, that is all technically speaking. In reality, Auto MDI-X has existed for 20 years and is included pretty much on every network interface that exists nowadays. The need for a cross-over cable is very rare, and is not likely necessary in your situation. This feature may also be called Auto uplink and trade, Universal Cable Recognition and Auto Sensing.
answered yesterday
Appleoddity
6,29021024
answered yesterday
Appleoddity
6,29021024
answered yesterday
Appleoddity
6,29021024
answered yesterday
Appleoddity
6,29021024
6,29021024
1
Part of why Auto-MDIX is practically everywhere is because 1000BASE-T no longer has separate transmit and receive lines. (All four pairs are bidirectional.)
– grawity
yesterday
Nit-pick - default router ports typically are in "PC configuration". I would change your 3rd paragraph to There are really only two different “modes†of ports. A port in host mode (e.g. PC, router) and a port in switch/hub mode.
– Digital Trauma
11 hours ago
@digitaltrauma ok. I’m not disagreeing, but do you have a reference on that regarding the default port mode?
– Appleoddity
9 hours ago
add a comment |Â
1
Part of why Auto-MDIX is practically everywhere is because 1000BASE-T no longer has separate transmit and receive lines. (All four pairs are bidirectional.)
– grawity
yesterday
Nit-pick - default router ports typically are in "PC configuration". I would change your 3rd paragraph to There are really only two different “modes†of ports. A port in host mode (e.g. PC, router) and a port in switch/hub mode.
– Digital Trauma
11 hours ago
@digitaltrauma ok. I’m not disagreeing, but do you have a reference on that regarding the default port mode?
– Appleoddity
9 hours ago
1
1
Part of why Auto-MDIX is practically everywhere is because 1000BASE-T no longer has separate transmit and receive lines. (All four pairs are bidirectional.)
– grawity
yesterday
Part of why Auto-MDIX is practically everywhere is because 1000BASE-T no longer has separate transmit and receive lines. (All four pairs are bidirectional.)
– grawity
yesterday
Nit-pick - default router ports typically are in "PC configuration". I would change your 3rd paragraph to There are really only two different “modes†of ports. A port in host mode (e.g. PC, router) and a port in switch/hub mode.
– Digital Trauma
11 hours ago
Nit-pick - default router ports typically are in "PC configuration". I would change your 3rd paragraph to There are really only two different “modes†of ports. A port in host mode (e.g. PC, router) and a port in switch/hub mode.
– Digital Trauma
11 hours ago
@digitaltrauma ok. I’m not disagreeing, but do you have a reference on that regarding the default port mode?
– Appleoddity
9 hours ago
@digitaltrauma ok. I’m not disagreeing, but do you have a reference on that regarding the default port mode?
– Appleoddity
9 hours ago
add a comment |Â
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Is it a semi-permanent setup with cables in walls etc? Or just a bunch of devices on a table? If latter, I would use any good cables and count on Auto MDI-X. Or do you deliberately want/need to allow hubs without this feature?
– Kamil Maciorowski
yesterday
I bought super cheap hubs from China so I'm honestly not even sure whether they have that feature. Is there a way to check? The setup does not have cabling in walls but it still needs to be permanent and reliable as it won't be me operating it and so I won't be on hand to fix any issues with cabling
– Matt
yesterday
@Matt Can you link us to the product page? I'd hope they're not actual hubs - the distinction is very important.
– Bob
yesterday
@Bob I went to go double check the page here ... I missed the part that said switch
– Matt
yesterday
1
It's definitely a switch, and the description below in that page actually explicitly mentions Auto-MDI/MDIX support, among various other switch-only features. (Slightly odd that the same page also says "Communication mode: Half-duplex" as opposed to full-duplex, but I guess they just copy-pasted whatever.)
– grawity
yesterday