Solved Understand and Apply Subnetting Part 2 - Default gateway

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Watching Understand and Apply Subnetting Part 2
Made me think what would be the default gateway in this example (when splitting a network into 4 smaller networks)Is it assigned by the admin to for example 192.168.10.1 when setting up a Cisco router?

192.168.10.0 (Network ID)
255.255.255.192 (1st network)
192.168.10.63 (Broadcast ID)
192.168.10.1 - 192.168.10.62 (Range)

Also, what would be the default gateway in this example?

192.168.10.64 (Network ID)
255.255.255.192 (2nd network)
192.168.10.125 (Broadcast ID)
192.168.10.65 - 192.168.10.126 (Range)

Anyone?

@hjalti-atlason said in Understand and Apply Subnetting Part 2 - Default gateway:

Watching Understand and Apply Subnetting Part 2
Made me think what would be the default gateway in this example (when splitting a network into 4 smaller networks)Is it assigned by the admin to for example 192.168.10.1 when setting up a Cisco router?

192.168.10.0 (Network ID)
255.255.255.192 (1st network)
192.168.10.63 (Broadcast ID)
192.168.10.1 - 192.168.10.62 (Range)

The default-gateway is ANY address in this range You as the network engineer would decided the number to be used. I generally like easy numbers to remember, so for me I would choose 192.168.10.1 but 192.168.10.59 would work just as well.

Also, what would be the default gateway in this example?

192.168.10.64 (Network ID)
255.255.255.192 (2nd network)
192.168.10.125 (Broadcast ID)
192.168.10.65 - 192.168.10.126 (Range)

Anyone?

Remember that the default-gateway or default-router doesn't have to be any specific address itself, as long as within the range of addresses.

Now, having said that, this is not to be confused with a default route, this address cannot be on the same router as you set it on but it is normally also within the same subnet.

NYEDGE1(config)#ip route 0.0.0.0 0.0.0.0 192.168.16.1
%Invalid next hop address (it's this router)
NYEDGE1(config)#

Also, the default-gateway is not is to be confused with an ip default-network.

• I created a static route to 8.8.8.8 in NYEDGE1
• The route to 8.8.8.8 must be in the routing table FIRST
• Note, the Gateway of last resort is not set

NYEDGE1#show ip route
<omitted code table>

Gateway of last resort is not set

     192.168.12.0/24 is subnetted, 1 subnets
C       192.168.12.1 is directly connected, GigabitEthernet0/2
     192.168.16.0/24 is subnetted, 1 subnets
C       192.168.16.1 is directly connected, GigabitEthernet0/0
S    8.8.8.8/29 [1/0] via 192.168.12.2

Configure ip default-network 8.8.8.8

• Examine the routing table
  • The static route is now a candidate route S*
  • The Gateway of last resort is 192.168.12.2 to network 8.8.8.8

NYEDGE1#config
NYEDGE1(config)#ip default-network 8.8.8.8
NYEDGE1#show ip route
<omitted code table>

Gateway of last resort is 192.168.12.2 to network 8.8.8.8

     192.168.12.0/24 is subnetted, 1 subnets
C       192.168.12.1 is directly connected, GigabitEthernet0/2
     192.168.16.0/24 is subnetted, 1 subnets
C       192.168.16.1 is directly connected, GigabitEthernet0/0
S*    8.8.8.8/29 [1/0] via 192.168.12.2

Let me know if I didn't answer what you were asking. Sometimes, I answer my own question and not what is meant.

Thank you for the answer Ronnie.

I got the part "The default-gateway is ANY address in this range You as the network engineer would decided the number to be used. I generally like easy numbers to remember, so for me I would choose 192.168.10.1 but 192.168.10.59 would work just as well." . I think watching more videos and reading the Show notes will help me to fully understand the last part of you're answer. I will review the answer again when that happens.

Thanks.

One quick question.

Are there different versions of IOS for Cisco switches and routers? I'm trying to set up GNS environment and want to make sure i'm using the right Cisco images for the routers and switches i set up.

Hi Hjalti,

Cisco do have different firmware images for different switches but the commands are generally the same. Features tend to be licensed for some of the more advanced functions.

Routers and Firewalls will have similar command sets to switches, but additional functions for the specific device type.

If you are just covering the basics of networking, setting up a GNS3 lab with a Cisco Layer 2 switch and a basic Cisco router should give you all of what you need. Networking hasn't changed that much over the years.

Mark

@hjalti-atlason said in Understand and Apply Subnetting Part 2 - Default gateway:

One quick question.

Are there different versions of IOS for Cisco switches and routers? I'm trying to set up GNS environment and want to make sure i'm using the right Cisco images for the routers and switches i set up.

In GNS3, there are a limited number of supported images AND they only support Router IOS images. Switches cannot be emulated in the GNS3 environment because of Cisco proprietary ASICs--ASICs cannot be emulated. Though it's a great low cost alternative to router emulation and network simulated environments it cannot do it all.

They are getting better and can do thing like Cisco ASA firewall and more beyond the realm of Cisco. The issue with the GNS3 on these other emulations is a steep learning curve that takes time.

Here is the best list of Cisco IOS images that can be used in Dynamips which is the underlying system for GNS3.

https://docs.gns3.com/1-kBrTplBltp9P3P-AigoMzlDO-ISyL1h3bYpOl5Q8mQ/

@ronnie-wong said in Understand and Apply Subnetting Part 2 - Default gateway:

@hjalti-atlason said in Understand and Apply Subnetting Part 2 - Default gateway:

One quick question.

Are there different versions of IOS for Cisco switches and routers? I'm trying to set up GNS environment and want to make sure i'm using the right Cisco images for the routers and switches i set up.

In GNS3, there are a limited number of supported images AND they only support Router IOS images. Switches cannot be emulated in the GNS3 environment because of Cisco proprietary ASICs--ASICs cannot be emulated. Though it's a great low cost alternative to router emulation and network simulated environments it cannot do it all.

They are getting better and can do thing like Cisco ASA firewall and more beyond the realm of Cisco. The issue with the GNS3 on these other emulations is a steep learning curve that takes time.

Here is the best list of Cisco IOS images that can be used in Dynamips which is the underlying system for GNS3.

https://docs.gns3.com/1-kBrTplBltp9P3P-AigoMzlDO-ISyL1h3bYpOl5Q8mQ/

Thanks

Here is a list of Cisco IOS images i have on my computer (With GNS3 setup on).
c1700-adventerprisek9-mz.124-8.bin
c2600-i-mz.123-9.bin
c2691-entservicesk9-mz.124-13b.bin
c3640-ik9o3s-mz124-13.bin
c3660-jk9o3s-mz.124-25d.bin
c3725-adventerprisek9-mz124-15.bin
c3745-advipservicesk9-mz.124-25d.bin
c7200-advipservicesk9-mz.152-4.S5.bin
c7200p-advipservicesk9-mz.152-4.S5.bin

If you would have to choose what images would you use ?

Edit: since there is no support for switches in GNS3 i might end up buying a Boson kit (and of course use the ITpro practice labs)

@hjalti-atlason said in Understand and Apply Subnetting Part 2 - Default gateway:

@ronnie-wong said in Understand and Apply Subnetting Part 2 - Default gateway:

@hjalti-atlason said in Understand and Apply Subnetting Part 2 - Default gateway:

One quick question.

Are there different versions of IOS for Cisco switches and routers? I'm trying to set up GNS environment and want to make sure i'm using the right Cisco images for the routers and switches i set up.

In GNS3, there are a limited number of supported images AND they only support Router IOS images. Switches cannot be emulated in the GNS3 environment because of Cisco proprietary ASICs--ASICs cannot be emulated. Though it's a great low cost alternative to router emulation and network simulated environments it cannot do it all.

They are getting better and can do thing like Cisco ASA firewall and more beyond the realm of Cisco. The issue with the GNS3 on these other emulations is a steep learning curve that takes time.

Here is the best list of Cisco IOS images that can be used in Dynamips which is the underlying system for GNS3.

https://docs.gns3.com/1-kBrTplBltp9P3P-AigoMzlDO-ISyL1h3bYpOl5Q8mQ/

Thanks

Here is a list of Cisco IOS images i have on my computer (With GNS3 setup on).
c1700-adventerprisek9-mz.124-8.bin
c2600-i-mz.123-9.bin
c2691-entservicesk9-mz.124-13b.bin
c3640-ik9o3s-mz124-13.bin
c3660-jk9o3s-mz.124-25d.bin
c3725-adventerprisek9-mz124-15.bin
c3745-advipservicesk9-mz.124-25d.bin
c7200-advipservicesk9-mz.152-4.S5.bin
c7200p-advipservicesk9-mz.152-4.S5.bin

If you would have to choose what images would you use ?

The original pre-GNS3 emulation engine (non-GUI) is DYNAMIPS. This was based on the 7200 routers.

• Advantages
  • this IOS is that it is what DYNAMIPS was designed for from its inception.
  • the ability to run IOS 15.x--this will give you the version tested and keep you away from legacy commands that may still work but not tested.
• Disadvantage
  • requires more RAM for each running image ~512MB for each emulated image
  • advipservicesk9 is a good image but may not provide you with every feature.

This is just a quick list of why I choose the the 7200...but I've also used the 2691 and 3640 to satisfaction as well.

Edit: since there is no support for switches in GNS3 i might end up buying a Boson kit (and of course use the ITpro practice labs)

The only drawback about ANY simulation product that offers switch simulations is that they are not emulators (So I'm not picking on Boson only). What this means practically is that you may not notice any difference between a working device and the simulation. Certain switch operations may not be real operations but a simulation of an operation. Also there are certain switch operations that may not work at all, in other words they will not be available. You may not be able to trust the output of show commands on certain operations. So be aware before you dive whole heartedly into product. Companies will tell you, you'll not see that on the exam or they show you an example of what the output should read. So going head with this approach will it work. Yes. But you may find the functionality limiting.

@ronnie-wong said in Understand and Apply Subnetting Part 2 - Default gateway:

@hjalti-atlason said in Understand and Apply Subnetting Part 2 - Default gateway:

@ronnie-wong said in Understand and Apply Subnetting Part 2 - Default gateway:

@hjalti-atlason said in Understand and Apply Subnetting Part 2 - Default gateway:

One quick question.

Are there different versions of IOS for Cisco switches and routers? I'm trying to set up GNS environment and want to make sure i'm using the right Cisco images for the routers and switches i set up.

In GNS3, there are a limited number of supported images AND they only support Router IOS images. Switches cannot be emulated in the GNS3 environment because of Cisco proprietary ASICs--ASICs cannot be emulated. Though it's a great low cost alternative to router emulation and network simulated environments it cannot do it all.

They are getting better and can do thing like Cisco ASA firewall and more beyond the realm of Cisco. The issue with the GNS3 on these other emulations is a steep learning curve that takes time.

Here is the best list of Cisco IOS images that can be used in Dynamips which is the underlying system for GNS3.

https://docs.gns3.com/1-kBrTplBltp9P3P-AigoMzlDO-ISyL1h3bYpOl5Q8mQ/

Thanks

Here is a list of Cisco IOS images i have on my computer (With GNS3 setup on).
c1700-adventerprisek9-mz.124-8.bin
c2600-i-mz.123-9.bin
c2691-entservicesk9-mz.124-13b.bin
c3640-ik9o3s-mz124-13.bin
c3660-jk9o3s-mz.124-25d.bin
c3725-adventerprisek9-mz124-15.bin
c3745-advipservicesk9-mz.124-25d.bin
c7200-advipservicesk9-mz.152-4.S5.bin
c7200p-advipservicesk9-mz.152-4.S5.bin

If you would have to choose what images would you use ?

The original pre-GNS3 emulation engine (non-GUI) is DYNAMIPS. This was based on the 7200 routers.

• Advantages
  • this IOS is that it is what DYNAMIPS was designed for from its inception.
  • the ability to run IOS 15.x--this will give you the version tested and keep you away from legacy commands that may still work but not tested.
• Disadvantage
  • requires more RAM for each running image ~512MB for each emulated image
  • advipservicesk9 is a good image but may not provide you with every feature.

This is just a quick list of why I choose the the 7200...but I've also used the 2691 and 3640 to satisfaction as well.

Edit: since there is no support for switches in GNS3 i might end up buying a Boson kit (and of course use the ITpro practice labs)

The only drawback about ANY simulation product that offers switch simulations is that they are not emulators (So I'm not picking on Boson only). What this means practically is that you may not notice any difference between a working device and the simulation. Certain switch operations may not be real operations but a simulation of an operation. Also there are certain switch operations that may not work at all, in other words they will not be available. You may not be able to trust the output of show commands on certain operations. So be aware before you dive whole heartedly into product. Companies will tell you, you'll not see that on the exam or they show you an example of what the output should read. So going head with this approach will it work. Yes. But you may find the functionality limiting.

Thank you Ronnie.

Noted.