Is sharing a single network connection between two servers dumb?



  • Is there much of a performance penalty for sharing the network connection into one server to another server from a port on the same card? Datacenter wants to charge me more money for a 3rd power outlet to run a switch and are only providing one Internet jack, would love to be able to get away w/

    The cord into server a
    A cord from server a to server b to share the connection.

    Each server has 4 ports.



  • Really depends on teh connection more than anything.



  • @creayt said in Is sharing a single network connection between two servers dumb?:

    Is there much of a performance penalty for sharing the network connection into one server to another server from a port on the same card? Datacenter wants to charge me more money for a 3rd power outlet to run a switch and are only providing one Internet jack, would love to be able to get away w/

    The cord into server a
    A cord from server a to server b to share the connection.

    Each server has 4 ports.

    but you can use those 4 ports to make bond and enhance the connection reliability. so o need for the switch IMO



  • @emad-r said in Is sharing a single network connection between two servers dumb?:

    @creayt said in Is sharing a single network connection between two servers dumb?:

    Is there much of a performance penalty for sharing the network connection into one server to another server from a port on the same card? Datacenter wants to charge me more money for a 3rd power outlet to run a switch and are only providing one Internet jack, would love to be able to get away w/

    The cord into server a
    A cord from server a to server b to share the connection.

    Each server has 4 ports.

    but you can use those 4 ports to make bond and enhance the connection reliability. so o need for the switch IMO

    Can you explain this in simple terms? If all 4 ports are depending on the same upstream single cable, how does it enhance reliability? Just in case one of the ports on my card fails, the other's'd still work? Does that happen or does the whole card fail?



  • @scottalanmiller said in Is sharing a single network connection between two servers dumb?:

    Really depends on teh connection more than anything.

    Sweet. So however good or terrible the connection is it'll be just as good or terrible ( or close to ) when hot potatoed through one server to the 2nd? The server being the middleman has 20 cores if that makes any performance difference for doing this.



  • @creayt said in Is sharing a single network connection between two servers dumb?:

    Can you explain this in simple terms? If all 4 ports are depending on the same upstream single cable, how does it enhance reliability? Just in case one of the ports on my card fails, the other's'd still work? Does that happen or does the whole card fail?

    Can you explain this in simple terms? If all 4 ports are depending on the same upstream single cable, how does it enhance reliability?

    It doesnt in your case, cause if that single cable was cut, you will lose the connection to the server.
    That said how many times a good isolated cable fails, especially if it was CAT6A and is already in tube housing... I dont think that I ever witnessed that.

    Just in case one of the ports on my card fails, the other's'd still work? Does that happen or does the whole card fail?

    Well, this is where networking bonding can help in. I reckon scott made an article, basically you can bond for performance or bond for redundancy (and if you have 4 ports I reckon you can do both), scott made article about bonding in Centos if I recall correctly, and ESXi has easy GUI option to deal with it.





  • Another thing to consider would be the best practices as far as it's implementation in Hyper-V goes, the best use case for NIC teaming would be a Active/Standby connection mode. You can find more details about it here - http://insidevirtualization.com/windows-server-2012-r2/windows-server-2012-r2-nic-teaming-options/



  • This isn't a NIC teaming situation.

    The OP has one internet connection that needs to be split over two servers.

    Normally one would install a switch and then run a cable from each server to the switch, and the switch to the internet... BUT - in this case, the OP doesn't have an open power socket for the switch (it would cost them more money) so they are looking for a way to do ICS (Internet connection sharing) from one server to the other.

    This really seems like a bad idea. I'm guessing this means no Out of Band connections for the servers, and only a single connection for both servers. So if the first server dies, the second one becomes useless.

    Really seems like a time to re-evaluate the priorities here - why are you in a DC if you can't afford these other seemingly needed things.



  • @dashrender said in Is sharing a single network connection between two servers dumb?:

    This isn't a NIC teaming situation.

    The OP has one internet connection that needs to be split over two servers.

    Normally one would install a switch and then run a cable from each server to the switch, and the switch to the internet... BUT - in this case, the OP doesn't have an open power socket for the switch (it would cost them more money) so they are looking for a way to do ICS (Internet connection sharing) from one server to the other.

    This really seems like a bad idea. I'm guessing this means no Out of Band connections for the servers, and only a single connection for both servers. So if the first server dies, the second one becomes useless.

    Really seems like a time to re-evaluate the priorities here - why are you in a DC if you can't afford these other seemingly needed things.

    Thanks for the response! If the first server died, the datacenter team would pull the cable from the dead server and immediately plug it into the 2nd server, so there'd be a small window of downtime, but it'd theoretically take over all duties immediately. Agree it's a bad idea, but this is all for a hobby project where some downtime is acceptable and I'm trying to really be a cheap muhfuh 🙂



  • I guess what I'm really looking for I guess is how much of a performance hit will the 2nd ( daisy-chained ) server have for internet connectivity, now that I know it's possible technically?



  • @creayt said in Is sharing a single network connection between two servers dumb?:

    I guess what I'm really looking for I guess is how much of a performance hit will the 2nd ( daisy-chained ) server have for internet connectivity, now that I know it's possible technically?

    Mostly will depend on how much of the connection workload will be put on main sys: if you are querying and the cpu if 100% and network load will hit it, well you will have impact. Remaining stuff should be neglectable.
    Can't think of anything at least.



  • @creayt said in Is sharing a single network connection between two servers dumb?:

    @dashrender said in Is sharing a single network connection between two servers dumb?:

    This isn't a NIC teaming situation.

    The OP has one internet connection that needs to be split over two servers.

    Normally one would install a switch and then run a cable from each server to the switch, and the switch to the internet... BUT - in this case, the OP doesn't have an open power socket for the switch (it would cost them more money) so they are looking for a way to do ICS (Internet connection sharing) from one server to the other.

    This really seems like a bad idea. I'm guessing this means no Out of Band connections for the servers, and only a single connection for both servers. So if the first server dies, the second one becomes useless.

    Really seems like a time to re-evaluate the priorities here - why are you in a DC if you can't afford these other seemingly needed things.

    Thanks for the response! If the first server died, the datacenter team would pull the cable from the dead server and immediately plug it into the 2nd server, so there'd be a small window of downtime, but it'd theoretically take over all duties immediately. Agree it's a bad idea, but this is all for a hobby project where some downtime is acceptable and I'm trying to really be a cheap muhfuh 🙂

    Not sure that would work. It would depend on how it's set up.


Log in to reply