Do window and linux suck when managing multiple subnet interfaces?

[ggnfs000]

created several NICs and each or some of them are connected to differnt vSwitches (or different vlan)-s. One of the network interface has connection to corporate network where internet can access. As long as this interface is the sole interface, it is OK. Once more NICs are added which are part of other vLAN-s Windows seem to suck. Can not access internet anymore. Perhaps confused by which interface to be used for net access. Not sure if there is a way to specifically tell specific interface to use the net. Saw similar problem in linux.

[Dieselboy]

You can only have one default gateway.

Also you probably need to make sure that the traffic is going out and coming back the same way.

on the interfaces without any default gateway, you need to have static routes to point the operating system out of which network adaptor to speak to which network. This is why generally, endpoints have one nic and routing is done on the network devices.

Remember, routing is locally significant in a sense that each device makes its own routing decision on a packet. It's a little bit different when you have a routing protocol but ultimately that's used to fill up the route table.

Both windows and linux have their own route table. Type "route" or "route print" at the CLI. But remember that routing is layer 3 and packets are sent using layer 2. 

[wintermute000]

not strictly true

Examples:
https://www.thomas-krenn.com/en/wiki/Two_Default_Gateways_on_One_System
https://kindlund.wordpress.com/2007/11/19/configuring-multiple-default-routes-in-linux/

Wait till you deal with load balancers....

[that1guy15]

ah yes. I remember when I got my CCNA and thought "I know all that is networking!' Then someone handed me an HP switch and I thought WTF are tagged and untagged ports? What am I missing? Did Cisco not teach me everything?

Then I learned that there is more than Cisco's way to do networking. Once I got a grasp on that I thought "surely I know all that is network now!!"

Then someone handed me a linux server...

[ggnfs000]

ah yes. I remember when I got my CCNA and thought "I know all that is networking!' Then someone handed me an HP switch and I thought WTF are tagged and untagged ports? What am I missing? Did Cisco not teach me everything?

Then I learned that there is more than Cisco's way to do networking. Once I got a grasp on that I thought "surely I know all that is network now!!"

Then someone handed me a linux server...

Yeah but Linux documention always sux and tools interfaces changing. User knowledge base is murky. It is not related to just networking related to Linux. When ever there is a troubleshooting effort in Linux it has never been straightforward.
This is where cisco ios rocks or at least much better imho.

[deanwebb]

Back to the OP, I recall from working with GNS3 that there's a way for Windows to allow traffic from GNS3 to connect to the Internet and I actually did it 4 years ago. I don't remember the particulars, but something similar to that may be what you're looking to do.

[icecream-guy]

Back to the OP, I recall from working with GNS3 that there's a way for Windows to allow traffic from GNS3 to connect to the Internet and I actually did it 4 years ago. I don't remember the particulars, but something similar to that may be what you're looking to do.

I think it was something like breaking out one of the GNS interfaces and connecting it to a real switch.

[deanwebb]

Back to the OP, I recall from working with GNS3 that there's a way for Windows to allow traffic from GNS3 to connect to the Internet and I actually did it 4 years ago. I don't remember the particulars, but something similar to that may be what you're looking to do.

I think it was something like breaking out one of the GNS interfaces and connecting it to a real switch.

Well there you go! Most of my work with multi-homed Windows devices was either to have them participate in port-channel groups for higher throughput bandwidth or to shut them down as hackers bridging unfiltered Internet into the corporate environment.

[NetworkGroover]

Back to the OP, I recall from working with GNS3 that there's a way for Windows to allow traffic from GNS3 to connect to the Internet and I actually did it 4 years ago. I don't remember the particulars, but something similar to that may be what you're looking to do.

I think it was something like breaking out one of the GNS interfaces and connecting it to a real switch.

I remember doing this like once and then never doing it again.  You create a cloud interface of some sort - forget what it's called.  I'm sure there's plenty of articles out there that talk about it.

[wintermute000]

ah yes. I remember when I got my CCNA and thought "I know all that is networking!' Then someone handed me an HP switch and I thought WTF are tagged and untagged ports? What am I missing? Did Cisco not teach me everything?

Then I learned that there is more than Cisco's way to do networking. Once I got a grasp on that I thought "surely I know all that is network now!!"

Then someone handed me a linux server...

Yeah but Linux documention always sux and tools interfaces changing. User knowledge base is murky. It is not related to just networking related to Linux. When ever there is a troubleshooting effort in Linux it has never been straightforward.
This is where cisco ios rocks or at least much better imho.

Stop googling blog posts and newbies posting on ubuntuforums etc. and go to official documentation.
There is a universe of linux knowledge out there and I am gobsmacked at your casual assertion.
Just go do a RHCA....


Also, did it ever occur to you that IOS does 1% of the functions of a full fat linux distro, geeze I wonder which one is more complicated.

[Dieselboy]

not strictly true

Examples:
https://www.thomas-krenn.com/en/wiki/Two_Default_Gateways_on_One_System
https://kindlund.wordpress.com/2007/11/19/configuring-multiple-default-routes-in-linux/

Wait till you deal with load balancers....

Your links describe setting up multiple routing tables. Thanks for the links - will be handy

OP
I've had a different experience to you with Linux. I find that there's so much documentation out there that it's overwhelming. May be the difficulty you found was knowing where to start? I find that if I'm running a command to do something, then checking the "man page" for help is a good start. Type "man" then the command to get to the man page.

[NetworkGroover]

OP
I've had a different experience to you with Linux. I find that there's so much documentation out there that it's overwhelming. May be the difficulty you found was knowing where to start? I find that if I'm running a command to do something, then checking the "man page" for help is a good start. Type "man" then the command to get to the man page.

+1

Whenever I have to do "Linux"-ey stuff, it's almost a matter of finding which correct answer of the 10 correct answers work in my case. xD

[ggnfs000]

ah yes. I remember when I got my CCNA and thought "I know all that is networking!' Then someone handed me an HP switch and I thought WTF are tagged and untagged ports? What am I missing? Did Cisco not teach me everything?

Then I learned that there is more than Cisco's way to do networking. Once I got a grasp on that I thought "surely I know all that is network now!!"

Then someone handed me a linux server...

Yeah but Linux documention always sux and tools interfaces changing. User knowledge base is murky. It is not related to just networking related to Linux. When ever there is a troubleshooting effort in Linux it has never been straightforward.
This is where cisco ios rocks or at least much better imho.

Stop googling blog posts and newbies posting on ubuntuforums etc. and go to official documentation.
There is a universe of linux knowledge out there and I am gobsmacked at your casual assertion.
Just go do a RHCA....


Also, did it ever occur to you that IOS does 1% of the functions of a full fat linux distro, geeze I wonder which one is more complicated.

as a matter of fact, it does not matter. linux open source contributors, technical writers just seem to be schmucks as casual users sometimes worse, official doc does not really help.

[NetworkGroover]

as a matter of fact, it does not matter. linux open source contributors, technical writers just seem to be schmucks as casual users sometimes worse, official doc does not really help.

Erm... it's open source... what are you expecting.  If you haven't learned already - our field is one of research - not everything is going to be neatly presented to you on a silver platter.

It's only gotten better since the existence of Github xD  Now everyone's a mad scientist.

[wintermute000]

I retiterate

Do everything on CentOS, do the RHCA, read the official RH doco. 90% of what you learn is portable across distributions, especially with systemd borging everything (not trying to start THAT flamewar again...)