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Questions pertaining to network interfaces and their validation errors

Monkey_Demon

Explorer
Joined
Nov 11, 2016
Messages
85
About 2-3 weeks ago, I stopped being able to access the NAS drive on my network. Pinging the IP addresses of the ethernet ports returned 100% packet loss. I spent a great deal of time troubleshooting, including swapping wires, resetting router settings, etc. Unable to diagnose the problem, I took the server into a local computer store, hoping to see if the communication ports were good. The tech found nothing wrong, and the system connected to his network without a hitch. But when I got it back home, it was the same old story -- no connectivity.

After almost 2 hrs on the phone with Linksys tech support, I had the bright idea of using IPMI to access the otherwise inaccessible server. Then, I was able to reboot the unit and watch the startup procedure. The server has 3 network ports: one IPMI and two regular Ethernet. Eventually, I deleted the two corresponding interfaces and reconfigured one. Using Network > Interfaces I was able to set one of the two Ethernet ports to a static IP address I had.

But when I went to set the second interface and its IP address. Here's the error message:

EINVAL interface-update aliased. The network 192.168.1.0/24 is already in use by another interface.

But I wasn't using no stinkin 192.168.1.0 address.

Do you have any idea what's going on?
 

no_connection

Patron
Joined
Dec 15, 2013
Messages
479
Are you trying to give it two IP addresses in the same subnet? It shuold not allow you to give it split brain. Since it won't know that interface to respond on.
 

Monkey_Demon

Explorer
Joined
Nov 11, 2016
Messages
85
Are you trying to give it two IP addresses in the same subnet? It shuold not allow you to give it split brain. Since it won't know that interface to respond on.

I don't quite understand your reply and probably should have provided more information.

The IPMI port is 192.168.1.190 and the first TCP/IP interface is 192.168.1.191/24. I was trying to set the second TCP/IP interface to 192.168.1.192/24. All three are static addresses assigned in the router.

The error message throws me because it refers to 192.168.1.0 rather than any of these. Also, I'm configuring two different ports, each with its own unique MAC address. So while they're both on subnet 192.168.1 (at least I believe this is true), they should be distinguishable.

What am I missing?
 
Joined
Jul 10, 2016
Messages
521
What am I missing?



 

no_connection

Patron
Joined
Dec 15, 2013
Messages
479
192.168.1.0/24 is the network address, think of it like a street name where IP addresses are the house numbers.
Your house can't have two addresses on the same street. Imagine walking up to to a house and and giving Bill a note to collect a package, he goes in to the house and then comes out another door on the other side of the house, which Bill would do since he don't know which front door to use since he put two of them in.
 

Monkey_Demon

Explorer
Joined
Nov 11, 2016
Messages
85
192.168.1.0/24 is the network address, think of it like a street name where IP addresses are the house numbers.
Your house can't have two addresses on the same street. Imagine walking up to to a house and and giving Bill a note to collect a package, he goes in to the house and then comes out another door on the other side of the house, which Bill would do since he don't know which front door to use since he put two of them in.

OK, this makes sense.

But since there are two NICs on the motherboard, I'd like to use both of them for these following purposes:
  • Backup -- in case the other NIC goes down
  • Throughput -- to communicate more data by having twice as many ports
  • (Perhaps) specialized communications -- using one of the two for very specific purposes (e.g., ssh root or admin logins)
Is there any way to accomplish such things? What's the best way?
 

no_connection

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Joined
Dec 15, 2013
Messages
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