Must 40/100G uplink ports on a 10G switch be connected to another switch?
Clash Royale CLAN TAG#URR8PPP
I'm looking at a switch like this:
https://www.fs.com/products/29123.html
It has 48 10-GbE SFP+ ports and 6 40-GbE uplink ports. I would like to use some of these uplinks to cross-connect to another switch. In addition to that, however, I have a server with a 40-GbE capable NIC in it. Can this be connected directly to the 40-GbE port on the switch and "just work," or are these uplink ports special in that they must connect to uplink ports on another switch?
I know this used to be a thing for copper-based cabling before Auto-MDIX became commonplace, but it's not clear to me whether it's still an issue for modern SFP/QSFP-based connections.
switch sfp uplinks 40g
add a comment |
I'm looking at a switch like this:
https://www.fs.com/products/29123.html
It has 48 10-GbE SFP+ ports and 6 40-GbE uplink ports. I would like to use some of these uplinks to cross-connect to another switch. In addition to that, however, I have a server with a 40-GbE capable NIC in it. Can this be connected directly to the 40-GbE port on the switch and "just work," or are these uplink ports special in that they must connect to uplink ports on another switch?
I know this used to be a thing for copper-based cabling before Auto-MDIX became commonplace, but it's not clear to me whether it's still an issue for modern SFP/QSFP-based connections.
switch sfp uplinks 40g
2
Without knowing the server specs, one can't say for sure, but I would expect that the NIC was designed to connect to a switch (you could ask what else would it connect to?).
– Ron Trunk
Mar 6 at 15:15
The server has this Mellanox NIC in it. I was making the assumption that there would be a standard answer to this type of question, as it's just a "vanilla" Ethernet NIC. The inherent question is whether the uplink ports on a switch like this are functionally any different from the others.
– Jason R
Mar 6 at 15:18
add a comment |
I'm looking at a switch like this:
https://www.fs.com/products/29123.html
It has 48 10-GbE SFP+ ports and 6 40-GbE uplink ports. I would like to use some of these uplinks to cross-connect to another switch. In addition to that, however, I have a server with a 40-GbE capable NIC in it. Can this be connected directly to the 40-GbE port on the switch and "just work," or are these uplink ports special in that they must connect to uplink ports on another switch?
I know this used to be a thing for copper-based cabling before Auto-MDIX became commonplace, but it's not clear to me whether it's still an issue for modern SFP/QSFP-based connections.
switch sfp uplinks 40g
I'm looking at a switch like this:
https://www.fs.com/products/29123.html
It has 48 10-GbE SFP+ ports and 6 40-GbE uplink ports. I would like to use some of these uplinks to cross-connect to another switch. In addition to that, however, I have a server with a 40-GbE capable NIC in it. Can this be connected directly to the 40-GbE port on the switch and "just work," or are these uplink ports special in that they must connect to uplink ports on another switch?
I know this used to be a thing for copper-based cabling before Auto-MDIX became commonplace, but it's not clear to me whether it's still an issue for modern SFP/QSFP-based connections.
switch sfp uplinks 40g
switch sfp uplinks 40g
edited Mar 8 at 8:34
Zac67
32.6k22163
32.6k22163
asked Mar 6 at 15:08
Jason RJason R
1503
1503
2
Without knowing the server specs, one can't say for sure, but I would expect that the NIC was designed to connect to a switch (you could ask what else would it connect to?).
– Ron Trunk
Mar 6 at 15:15
The server has this Mellanox NIC in it. I was making the assumption that there would be a standard answer to this type of question, as it's just a "vanilla" Ethernet NIC. The inherent question is whether the uplink ports on a switch like this are functionally any different from the others.
– Jason R
Mar 6 at 15:18
add a comment |
2
Without knowing the server specs, one can't say for sure, but I would expect that the NIC was designed to connect to a switch (you could ask what else would it connect to?).
– Ron Trunk
Mar 6 at 15:15
The server has this Mellanox NIC in it. I was making the assumption that there would be a standard answer to this type of question, as it's just a "vanilla" Ethernet NIC. The inherent question is whether the uplink ports on a switch like this are functionally any different from the others.
– Jason R
Mar 6 at 15:18
2
2
Without knowing the server specs, one can't say for sure, but I would expect that the NIC was designed to connect to a switch (you could ask what else would it connect to?).
– Ron Trunk
Mar 6 at 15:15
Without knowing the server specs, one can't say for sure, but I would expect that the NIC was designed to connect to a switch (you could ask what else would it connect to?).
– Ron Trunk
Mar 6 at 15:15
The server has this Mellanox NIC in it. I was making the assumption that there would be a standard answer to this type of question, as it's just a "vanilla" Ethernet NIC. The inherent question is whether the uplink ports on a switch like this are functionally any different from the others.
– Jason R
Mar 6 at 15:18
The server has this Mellanox NIC in it. I was making the assumption that there would be a standard answer to this type of question, as it's just a "vanilla" Ethernet NIC. The inherent question is whether the uplink ports on a switch like this are functionally any different from the others.
– Jason R
Mar 6 at 15:18
add a comment |
1 Answer
1
active
oldest
votes
That switch uses (Q)SFP+ ports which are essentially PHYless. You need to either use matching PHY type transceivers on both the switch and the host ports (e.g. 10GBASE-SR or 40GBASE-SR4) or direct-attach cables that are compatible with both sides.
The Mellanox NIC has QSFP28 ports that should support QSFP+ modules as well - check the documentation.
Note that most switches or NICs only support correctly branded transceivers - directly from the vendor or 3rd party compatible ones.
Whether the switch connects to a host or to another switch generally doesn't matter, assuming the port functions are configured appropriately.
MDI/MDI-X/Auto MDI-X are a special function of twisted-pair ports. The reason is that TP cables are straight-through historically and the receiver/transmitter crossover happens inside one of the link ports.
(Q)SFP(+) ports are all the same, the crossover happens within the cable (fiber or DAC).
2
"Whether the switch connects to a host or to another switch generally doesn't matter" is the real answer, maybe should be on top?
– aaaaaa
Mar 6 at 23:49
@aaaaaa Well, it may in some rare instances (twisted pair without Auto MDI-X), so I wanted to make sure the scenario is clear. I do actually disable Auto MDI-X on downlink and edge ports, and leave it enabled only on uplink ports.
– Zac67
Mar 7 at 21:04
add a comment |
Your Answer
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "496"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fnetworkengineering.stackexchange.com%2fquestions%2f57449%2fmust-40-100g-uplink-ports-on-a-10g-switch-be-connected-to-another-switch%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
That switch uses (Q)SFP+ ports which are essentially PHYless. You need to either use matching PHY type transceivers on both the switch and the host ports (e.g. 10GBASE-SR or 40GBASE-SR4) or direct-attach cables that are compatible with both sides.
The Mellanox NIC has QSFP28 ports that should support QSFP+ modules as well - check the documentation.
Note that most switches or NICs only support correctly branded transceivers - directly from the vendor or 3rd party compatible ones.
Whether the switch connects to a host or to another switch generally doesn't matter, assuming the port functions are configured appropriately.
MDI/MDI-X/Auto MDI-X are a special function of twisted-pair ports. The reason is that TP cables are straight-through historically and the receiver/transmitter crossover happens inside one of the link ports.
(Q)SFP(+) ports are all the same, the crossover happens within the cable (fiber or DAC).
2
"Whether the switch connects to a host or to another switch generally doesn't matter" is the real answer, maybe should be on top?
– aaaaaa
Mar 6 at 23:49
@aaaaaa Well, it may in some rare instances (twisted pair without Auto MDI-X), so I wanted to make sure the scenario is clear. I do actually disable Auto MDI-X on downlink and edge ports, and leave it enabled only on uplink ports.
– Zac67
Mar 7 at 21:04
add a comment |
That switch uses (Q)SFP+ ports which are essentially PHYless. You need to either use matching PHY type transceivers on both the switch and the host ports (e.g. 10GBASE-SR or 40GBASE-SR4) or direct-attach cables that are compatible with both sides.
The Mellanox NIC has QSFP28 ports that should support QSFP+ modules as well - check the documentation.
Note that most switches or NICs only support correctly branded transceivers - directly from the vendor or 3rd party compatible ones.
Whether the switch connects to a host or to another switch generally doesn't matter, assuming the port functions are configured appropriately.
MDI/MDI-X/Auto MDI-X are a special function of twisted-pair ports. The reason is that TP cables are straight-through historically and the receiver/transmitter crossover happens inside one of the link ports.
(Q)SFP(+) ports are all the same, the crossover happens within the cable (fiber or DAC).
2
"Whether the switch connects to a host or to another switch generally doesn't matter" is the real answer, maybe should be on top?
– aaaaaa
Mar 6 at 23:49
@aaaaaa Well, it may in some rare instances (twisted pair without Auto MDI-X), so I wanted to make sure the scenario is clear. I do actually disable Auto MDI-X on downlink and edge ports, and leave it enabled only on uplink ports.
– Zac67
Mar 7 at 21:04
add a comment |
That switch uses (Q)SFP+ ports which are essentially PHYless. You need to either use matching PHY type transceivers on both the switch and the host ports (e.g. 10GBASE-SR or 40GBASE-SR4) or direct-attach cables that are compatible with both sides.
The Mellanox NIC has QSFP28 ports that should support QSFP+ modules as well - check the documentation.
Note that most switches or NICs only support correctly branded transceivers - directly from the vendor or 3rd party compatible ones.
Whether the switch connects to a host or to another switch generally doesn't matter, assuming the port functions are configured appropriately.
MDI/MDI-X/Auto MDI-X are a special function of twisted-pair ports. The reason is that TP cables are straight-through historically and the receiver/transmitter crossover happens inside one of the link ports.
(Q)SFP(+) ports are all the same, the crossover happens within the cable (fiber or DAC).
That switch uses (Q)SFP+ ports which are essentially PHYless. You need to either use matching PHY type transceivers on both the switch and the host ports (e.g. 10GBASE-SR or 40GBASE-SR4) or direct-attach cables that are compatible with both sides.
The Mellanox NIC has QSFP28 ports that should support QSFP+ modules as well - check the documentation.
Note that most switches or NICs only support correctly branded transceivers - directly from the vendor or 3rd party compatible ones.
Whether the switch connects to a host or to another switch generally doesn't matter, assuming the port functions are configured appropriately.
MDI/MDI-X/Auto MDI-X are a special function of twisted-pair ports. The reason is that TP cables are straight-through historically and the receiver/transmitter crossover happens inside one of the link ports.
(Q)SFP(+) ports are all the same, the crossover happens within the cable (fiber or DAC).
edited Mar 6 at 16:07
answered Mar 6 at 15:54
Zac67Zac67
32.6k22163
32.6k22163
2
"Whether the switch connects to a host or to another switch generally doesn't matter" is the real answer, maybe should be on top?
– aaaaaa
Mar 6 at 23:49
@aaaaaa Well, it may in some rare instances (twisted pair without Auto MDI-X), so I wanted to make sure the scenario is clear. I do actually disable Auto MDI-X on downlink and edge ports, and leave it enabled only on uplink ports.
– Zac67
Mar 7 at 21:04
add a comment |
2
"Whether the switch connects to a host or to another switch generally doesn't matter" is the real answer, maybe should be on top?
– aaaaaa
Mar 6 at 23:49
@aaaaaa Well, it may in some rare instances (twisted pair without Auto MDI-X), so I wanted to make sure the scenario is clear. I do actually disable Auto MDI-X on downlink and edge ports, and leave it enabled only on uplink ports.
– Zac67
Mar 7 at 21:04
2
2
"Whether the switch connects to a host or to another switch generally doesn't matter" is the real answer, maybe should be on top?
– aaaaaa
Mar 6 at 23:49
"Whether the switch connects to a host or to another switch generally doesn't matter" is the real answer, maybe should be on top?
– aaaaaa
Mar 6 at 23:49
@aaaaaa Well, it may in some rare instances (twisted pair without Auto MDI-X), so I wanted to make sure the scenario is clear. I do actually disable Auto MDI-X on downlink and edge ports, and leave it enabled only on uplink ports.
– Zac67
Mar 7 at 21:04
@aaaaaa Well, it may in some rare instances (twisted pair without Auto MDI-X), so I wanted to make sure the scenario is clear. I do actually disable Auto MDI-X on downlink and edge ports, and leave it enabled only on uplink ports.
– Zac67
Mar 7 at 21:04
add a comment |
Thanks for contributing an answer to Network Engineering Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fnetworkengineering.stackexchange.com%2fquestions%2f57449%2fmust-40-100g-uplink-ports-on-a-10g-switch-be-connected-to-another-switch%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
2
Without knowing the server specs, one can't say for sure, but I would expect that the NIC was designed to connect to a switch (you could ask what else would it connect to?).
– Ron Trunk
Mar 6 at 15:15
The server has this Mellanox NIC in it. I was making the assumption that there would be a standard answer to this type of question, as it's just a "vanilla" Ethernet NIC. The inherent question is whether the uplink ports on a switch like this are functionally any different from the others.
– Jason R
Mar 6 at 15:18