Difference between revisions of "VLS2VLS-Routing"

From CDOT Wiki
Jump to: navigation, search
(→‎Manually configure routes on the gateways to reach VMs in other virtual)
(→‎Shell Script for adding custom routes on your gateway to other's VLSs)
 
(5 intermediate revisions by the same user not shown)
Line 95: Line 95:
 
* ip route show
 
* ip route show
  
−
== Manually Configure routes on each VM in each virtual network ==
+
== Manually Configure routes on each VM in each VLS ==
−
On Virtual Network 1's VM (192.168.1.2 .. 192.168.1.254)
+
You only need to create the custom routes on the VM in your VLS, but make sure that other students have proper routes on their VMs as well.
−
* route add -net 192.168.2.0 netmask 255.255.255.0 gw 192.168.1.1
+
=== VLS 1 VM2 to VM4 ===
−
* route add -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.1.1
+
On VLS 1's VM (192.168.1.2 .. 192.168.1.4)
 +
* nmcli con modify ens224 +ipv4.routes "192.168.0.0/16 192.168.1.1 100"
 +
* nmcli con down ens224
 +
* nmcli con up ens224
 +
* ip route show
  
−
On Virtual Network 2's VM (192.168.2.2 .. 192.168.1.254)
+
=== VLS 2 VM2 to VM4 ===
−
* route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.2.1
+
On VLS 2's VM (192.168.2.2 .. 192.168.2.4)
−
* route add -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.2.1
+
* nmcli con modify ens224 +ipv4.routes "192.168.0.0/16 192.168.2.1 100"
 +
* nmcli con down ens224
 +
* nmcli con up ens224
 +
* ip route show
  
−
On Virtual Network 3's VM (192.168.3.2 .. 192.168.3.254)
+
=== VLS 3 VM2 to VM4 ===
−
* route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.3.1
+
On VLS 3's VM (192.168.3.2 .. 192.168.3.4)
−
* route add -net 192.168.2.0 netmask 255.255.255.0 gw 192.168.3.1
+
* nmcli con modify ens224 +ipv4.routes "192.168.0.0/16 192.168.3.1 100"
 +
* nmcli con down ens224
 +
* nmcli con up ens224
 +
* ip route show
  
 
= Automate the process using BASH script =
 
= Automate the process using BASH script =
−
The above example shows that 12 route commands will be needed to create the necessary routes just for 3 virtual networks, each with a gateway and one VM. It will be difficult to manage all the routes if the number of virtual networks is much greater. The following script will be more practical if your need to set up all the necessary routes for a large number of virtual networks. Both script use the shell environment variables "MY_NETWORK_NO" and "OTHER_NETWORKS" to allow customization for different values of private network address.
+
The above example shows that 2 custom routes on each VLS are needed to provides the proper routing to reach 2 other VLS on the your gateway (VM1). It will be quite time consuming to manage all the routes if the number of VLS is much greater (how about 40 VLSs?). The following script will be more practical if your need to set up all the necessary routes for a large number of VLSs. Both scripts use the shell environment variables "MY_VLS_NO" and "OTHER_VLS_NOS" to allow customization for different values of VLSs.
 
   
 
   
−
== Shell Script for adding the proper routes on your gateway to other's private network ==
+
== Shell Script for adding custom routes on your gateway to other's VLSs ==
−
* set the shell variable MY_NETWORK_NO to your assigned network ID (we use 99 here is an example, please change 99 to your assigned network ID)
+
* set the shell variable MY_VLS_NO to your assigned network ID (I use 2 here as an example, please change 2 to your assigned network ID)
 
<pre>
 
<pre>
−
export MY_NETWORK_NO=99
+
export MY_VLS_NO=2
 
</pre>
 
</pre>
−
* set the shell variable OTHER_NETWORKS to the list of private network you want to create a route. The following example assign the list of network numbers 32, 33, 34, 35, 40, 41, and 99 that you want to create a route on your gateway:
+
* edit the shell variable OTHER_VLS_NOS to the list of VLS you want to have a route to their VLS network. The following example assign the list of network numbers 1 to 43 that you want to create a custom route on your gateway.
 
<pre>
 
<pre>
−
export OTHER_NETWORKS="32 33 34 35 40 41 99"
+
  OTHER_VLS_NOS=`seq 1 43`
 
</pre>
 
</pre>
−
The following Bash script to add 7 new route to your gateway host's routing table:
+
 
 +
The following Bash script to add 42 new custom routes to your gateway VM's routing table:
 
<pre>
 
<pre>
 
#! /bin/bash
 
#! /bin/bash
−
if [ -z "$MY_NETWORK_NO" ]
+
if [ -z "$MY_VLS_NO" ]
 
then
 
then
 
echo "Please run the following command to assign your network number" >&2
 
echo "Please run the following command to assign your network number" >&2
−
echo "to the shell varible MY_NETWORK_NO and run this script again." >&2
+
echo "to the shell varible MY_VLS_NO and run this script again." >&2
 
echo "Please replace xx with your actual network number." >&2
 
echo "Please replace xx with your actual network number." >&2
−
echo "  export MY_NETWORK_NO=xx" >&2
+
echo "  export MY_VLS_NO=xx" >&2
 
exit 1
 
exit 1
 
fi
 
fi
−
X=${MY_NETWORK_NO}
+
X=${MY_VLS_NO}
 
echo "Your Network Number is $X"
 
echo "Your Network Number is $X"
−
if [ -z "$OTHER_NETWORKS" ]
+
 
−
then
+
# change the following variable if necessary
−
echo "Please run the following command to assign the list of " >&2
+
OTHER_VLS_NOS=`seq 1 43`
−
echo "private networks you want to add a route on your gateway " >&2
+
 
−
echo "to the shell variable OTHER_NETWORKS and run this script again." >&2
+
Y=`echo ${OTHER_VLS_NOS}`
−
echo "The following command assign 32, 33, 34, 35, 40, 41, and 99" >&2
+
echo "Route to be added for the network number(s) $Y"
−
echo "to the variable OTHER_NETWORKS. Please replace those number" >&2
 
−
echo "with the ones you actually wanted." >&2
 
−
echo "  export OTHER_NETWORKS=\"32 33 34 35 40 41 99\"" >&2
 
−
exit 2
 
−
fi
 
−
Y=${OTHER_NETWORKS}
 
−
echo "Route to be add for the network number(s) $Y"
 
 
echo -n "Press ENTER to continue ... "
 
echo -n "Press ENTER to continue ... "
 
read dummy
 
read dummy
Line 154: Line 158:
 
if [ "$X" -ne "$y" ]
 
if [ "$X" -ne "$y" ]
 
then
 
then
−
    route add -net 192.168.${y}.0 netmask 255.255.255.0 gw 172.16.${y}.1
+
    nmcli con modify ens192 +ipv4.routes "192.168.${y}.0/24 172.20.${y}.1 100"
 
    echo "Adding route to 192.168.${y}.0 network."  
 
    echo "Adding route to 192.168.${y}.0 network."  
 
fi
 
fi
 
done
 
done
−
 
+
nmcli con down ens192
−
# enable IP forwarding on the gateway
+
nmcli con up ens192
 +
ip route show
 +
 +
# enable IP forwarding on the gateway, add "net.ipv4.ip_forward = 1" to /etc/sysctl.conf
 
echo "1" > /proc/sys/net/ipv4/ip_forward
 
echo "1" > /proc/sys/net/ipv4/ip_forward
−
 
−
</pre>
 
−
 
−
== Shell Script for adding the proper routes on your VM (all Linux VMs) to other's private network ==
 
−
* set the shell variable MY_NETWORK_NO to your assigned network ID (we use 99 here is an example, please change 99 to your assigned network ID)
 
−
<pre>
 
−
export MY_NETWORK_NO=99
 
−
</pre>
 
−
* set the shell variable OTHER_NETWORKS to the list of private network you want to create a route. The following example assign the list of network numbers 32, 33, 34, 35, 40, 41, and 99 that you want to create a route on your gateway:
 
−
<pre>
 
−
export OTHER_NETWORKS="32 33 34 35 40 41 99"
 
−
</pre>
 
−
The following Bash script to add 7 new route to your VM's routing table:
 
−
<pre>
 
−
#! /bin/bash
 
−
if [ -z "$MY_NETWORK_NO" ]
 
−
then
 
−
echo "Please run the following command to assign your network number" >&2
 
−
echo "to the shell varible MY_NETWORK_NO and run this script again." >&2
 
−
echo "Please replace xx with your actual network number." >&2
 
−
echo "  export MY_NETWORK_NO=xx" >&2
 
−
exit 1
 
−
fi
 
−
X=${MY_NETWORK_NO}
 
−
echo "Your Network Number is $X"
 
−
if [ -z "$OTHER_NETWORKS" ]
 
−
then
 
−
echo "Please run the following command to assign the list of " >&2
 
−
echo "private networks you want to add a route on your gateway " >&2
 
−
echo "to the shell variable OTHER_NETWORKS and run this script again." >&2
 
−
echo "The following command assign 32, 33, 34, 35, 40, 41, and 99" >&2
 
−
echo "to the variable OTHER_NETWORKS. Please replace those number" >&2
 
−
echo "with the ones you actually wanted." >&2
 
−
echo "  export OTHER_NETWORKS=\"32 33 34 35 40 41 99\"" >&2
 
−
exit 2
 
−
fi
 
−
Y=${OTHER_NETWORKS}
 
−
echo "Route to be add for the network number(s) $Y"
 
−
echo -n "Press ENTER to continue ... "
 
−
read dummy
 
−
 
−
# Add new route
 
−
for y in $Y
 
−
do
 
−
if [ "$X" -ne "$y" ]
 
−
then
 
−
    route add -net 192.168.${y}.0 netmask 255.255.255.0 gw 192.168.${X}.1
 
−
    echo "Adding route to 192.168.${y}.0 network via 192.168.${X}.1"
 
−
fi
 
−
 
−
done
 
−
 
−
# Add route to the 172.16.0.0 network
 
−
route add -net 172.16.0.0 netmask 255.255.0.0 gw 192.168.${X}.1
 
  
 
</pre>
 
</pre>

Latest revision as of 12:02, 22 March 2021

Background Information

The following configuration may be used to set up the proper routes between private Virtual LAN Segments (VLS) in OPS535 Virtual Lab on CentOS 8.x virtual machines. The custom routes added to the gateway VM (VM1), and their corresponding VMs (VM2 to VM4) in their private VLS will enable VMs in each private VLS to communicate with VMs in the other private VLS.


Virtual LAN Segment setting

Consider three VLSs (one for each student) where there are 3 gateways, one for each VLS in the OPS535 virtual lab:

VLS 1

VLS network: 192.168.1.0/24

Gateway (Host) IPs: Internal (ens224): 192.168.1.1 External (ens192): 172.20.1.1

VMs IPs:

  • VM2: 192.168.1.2
  • VM3: 192.168.1.3
  • VM4: 192.168.1.4

Default gateway on each VM2: 172.20.255.1 Gateway to the 192.168.0.0/16 network: 192.168.1.1

VLS 2

VLS network: 192.168.2.0/24

Gateway (Host) IPs: Internal (ens224): 192.168.2.1 External (ens192): 172.20.2.1

VMs IPs:

  • VM2: 192.168.2.2
  • VM3: 192.168.2.3
  • VM4: 192.168.2.4

Default gateway on each VM2: 172.20.255.1 Gateway to the 192.168.0.0/16 network: 192.168.2.1

VLS 3

VLS network: 192.168.3.0/24

Gateway (Host) IPs: Internal (ens224): 192.168.3.1 External (ens192): 172.20.3.1

VMs IPs:

  • VM2: 192.168.3.2
  • VM3: 192.168.3.3
  • VM4: 192.168.3.4

Default gateway on each VM2: 172.20.255.1 Gateway to the 192.168.0.0/16 network: 192.168.3.1


Manually configure custom routes on the gateways to reach VMs in other VLSs

You only need to create the custom routes on your own VLS, but make sure that other student's VLS has the custom routes to your VLS.

On VLS 1

On VLS 1's gateway (192.168.1.1 or 172.20.1.1): Using nmcli:

  • nmcli con modify ens192 +ipv4.routes "192.168.2.0/24 172.20.2.1 100"
  • nmcli con modify ens192 +ipv4.routes "192.168.3.0/24 172.20.3.1 100"
  • nmcli con down ens192
  • nmcli con up ens192

Check to make sure that your kernel routing table has the proper entries with the following command:

  • ip route show

On VLS 2

On VLS 2's gateway (192.168.2.1 or 172.20.2.1): Using nmcli:

  • nmcli con modify ens192 +ipv4.routes "192.168.1.0/24 172.20.1.1 100"
  • nmcli con modify ens192 +ipv4.routes "192.168.3.0/24 172.20.3.1 100"
  • nmcli con down ens192
  • nmcli con up ens192

Check to make sure that your kernel routing table has the proper entries with the following command:

  • ip route show

On VLS 3

On VLS 3's gateway (192.168.3.1 or 172.20.3.1): Using nmcli:

  • nmcli con modify ens192 +ipv4.routes "192.168.1.0/24 172.20.1.1 100"
  • nmcli con modify ens192 +ipv4.routes "192.168.2.0/24 172.20.2.1 100"
  • nmcli con down ens192
  • nmcli con up ens192

Check to make sure that your kernel routing table has the proper entries with the following command:

  • ip route show

Manually Configure routes on each VM in each VLS

You only need to create the custom routes on the VM in your VLS, but make sure that other students have proper routes on their VMs as well.

VLS 1 VM2 to VM4

On VLS 1's VM (192.168.1.2 .. 192.168.1.4)

  • nmcli con modify ens224 +ipv4.routes "192.168.0.0/16 192.168.1.1 100"
  • nmcli con down ens224
  • nmcli con up ens224
  • ip route show

VLS 2 VM2 to VM4

On VLS 2's VM (192.168.2.2 .. 192.168.2.4)

  • nmcli con modify ens224 +ipv4.routes "192.168.0.0/16 192.168.2.1 100"
  • nmcli con down ens224
  • nmcli con up ens224
  • ip route show

VLS 3 VM2 to VM4

On VLS 3's VM (192.168.3.2 .. 192.168.3.4)

  • nmcli con modify ens224 +ipv4.routes "192.168.0.0/16 192.168.3.1 100"
  • nmcli con down ens224
  • nmcli con up ens224
  • ip route show

Automate the process using BASH script

The above example shows that 2 custom routes on each VLS are needed to provides the proper routing to reach 2 other VLS on the your gateway (VM1). It will be quite time consuming to manage all the routes if the number of VLS is much greater (how about 40 VLSs?). The following script will be more practical if your need to set up all the necessary routes for a large number of VLSs. Both scripts use the shell environment variables "MY_VLS_NO" and "OTHER_VLS_NOS" to allow customization for different values of VLSs.

Shell Script for adding custom routes on your gateway to other's VLSs

  • set the shell variable MY_VLS_NO to your assigned network ID (I use 2 here as an example, please change 2 to your assigned network ID)
export MY_VLS_NO=2
  • edit the shell variable OTHER_VLS_NOS to the list of VLS you want to have a route to their VLS network. The following example assign the list of network numbers 1 to 43 that you want to create a custom route on your gateway.
   OTHER_VLS_NOS=`seq 1 43`

The following Bash script to add 42 new custom routes to your gateway VM's routing table: 

#! /bin/bash
if [ -z "$MY_VLS_NO" ]
then
	echo "Please run the following command to assign your network number" >&2
	echo "to the shell varible MY_VLS_NO and run this script again." >&2
	echo "Please replace xx with your actual network number." >&2
	echo "  export MY_VLS_NO=xx" >&2
	exit 1
fi
X=${MY_VLS_NO}
echo "Your Network Number is $X"

# change the following variable if necessary
OTHER_VLS_NOS=`seq 1 43`

Y=`echo ${OTHER_VLS_NOS}`
echo "Route to be added for the network number(s) $Y"
echo -n "Press ENTER to continue ... "
read dummy

# Add new route
for y in $Y
do
	if [ "$X" -ne "$y" ]
	then
	    nmcli con modify ens192 +ipv4.routes "192.168.${y}.0/24 172.20.${y}.1 100"
	    echo "Adding route to 192.168.${y}.0 network." 
	fi
done
nmcli con down ens192
nmcli con up ens192
ip route show
 
# enable IP forwarding on the gateway, add "net.ipv4.ip_forward = 1" to /etc/sysctl.conf 
echo "1" > /proc/sys/net/ipv4/ip_forward
Retrieved from "https://wiki.cdot.senecapolytechnic.ca/w/index.php?title=VLS2VLS-Routing&oldid=154490"