8 Posts

December 5th, 2017 09:00

Hello,

thank you for your answer. In general what I want to achieve is pretty easy in theory, but I do not know how to configure it exactly. Basically I do not need any VLAN tagging, I only want to make sure that on specific ports only specific IPs or subnets are allowed.

Lets assume I have 10.0.1.0/24 and 10.0.2.0/24 avaliable on the switch. Now I want to make sure that for example on Port 2 a device behind it can only assing IPs in range of 10.0.1.0/27 and a device on Port 3 can only assing lets say the single addresses 10.0.1.100 and 10.0.2.100. Ideally all devices with these individual assignments are in their own VLAN.

So I went the way that I create an own VLAN for each port and then use the vlan association subnet function to assign IPs or subnets to each VLAN for each port, but as I read this is not the way it works, right? Or am I just doing something wrong with the configuration of the VLANs.

Greetings!

8 Posts

December 5th, 2017 10:00

Fully static IP addresses. They are always set manually.

8 Posts

December 5th, 2017 11:00

Thank you for your answer. This is what I tried already as well. As soon as I set the ports to access mode with the VLAN I configured for the IPs I want to have assigned I do not get connection anymore.

The Uplink is always configured as general port with VLAN 1 and the additional VLANs for each of my ports.

Greetings!

8 Posts

December 5th, 2017 11:00

Thank you for your answer and your help!

The relevant configuration is currently like this:

console#show running-config

!Current Configuration:
!System Description "PowerConnect 6248, 3.3.16.1, VxWorks 6.5"
!System Software Version 3.3.16.1
!Cut-through mode is configured as disabled
!
configure
vlan database
vlan 11
vlan association subnet XXX.230.163.0 255.255.255.248 11
vlan association subnet XXX.230.163.10 255.255.255.255 11

description "Uplink"
switchport mode general
switchport general allowed vlan add 11
exit
!

interface ethernet 1/g34
negotiation 100h
description "INET"
switchport mode general
switchport general allowed vlan add 11
exit
!
interface ethernet 1/g35
negotiation 100h


description "iLo"
switchport mode general
switchport general allowed vlan add 11
exit

I tested it by pinging external from the internet. I´m working with external IP addresses. I did not ping from device to device only trough the switch.

Greetings!

8 Posts

December 5th, 2017 13:00

Hello,

thank you alot for your very detailed description. The problem I have is that I generally have absolutely no control of the configuration of the gateway. I can tell which configuration I need, but they are most likely not able to configure my VLANs on their infrastrcture. I´m in a data center and have the uplink provided together with all external ip addresses I´m allowed to use.

 I just want to make sure that IP addresses are bound to specific ports, so I´m able to ensure that clients on a port can only use the IPs I want them to use. This means I´m only able to operate within the PowerConnect6248. Is it possible to perform this routing with the switch maybe with something like inter vlan routing?

Greetings!

8 Posts

December 5th, 2017 15:00

Thank you for your reply. Currently no VLANs are in use but VLAN 1, so I´m already running on a flat network. The only reason applying VLANs for me was my intension to limit IP addresses on a port. I also have no idea about the gateways hardware, I´m sorry. Currently it is just Uplink -> 6248 -> Clients.

So my way would be that I create an IP ACL for each port to ensure that only the IPs/Subnets I specify there are usable. How is the syntax here? Do I need to allow the IPs I want in first place and deny all others afterwards or do I just need my allow rule?

Greetings!

-> UPDATE

I just tried it out and I set the following configuration for a Port which is only expected to use one single IP:

interface ethernet 1/g35
negotiation 100h
description "iLo"
ip access-group deny out 11
ip access-group deny in 10
ip access-group iLo in 9
ip access-group iLo out 8
exit

Deny is set to deny IP Protocol from 0.0.0.0. 0.0.0.0 so everything.

After that I set rule iLo to permit the specific IP I want once inbound and outbound with a higher priority. The result is that after I did the deny nothing was pinging, and after I applied the permit with rule iLo it was pinging again. So this is most likely what you suggested and I guess this solved my problem.

I will try this tomorrow on another interface with a server behind which is virtualized and uses several IPs to finally confirm this. So I can test it by applying foreign IPs I do not allow with ACL to a Linux VM and see if it gets a connection. (It´s really late here already). I will come back and share my results, but I´m very confident that this is exactly what I needed. Thank you so much!

Greetings!

8 Posts

December 6th, 2017 03:00

Hello!

As a summary in case this is relevant for anyone else:

I configured one ACL like this:

console(config)# access-list test permit ip 192.230.163.0 0.0.0.7 0.0.0.0 255.255.255.255

This will allow subnet 192.230.163.0/29 to be reachable by 0.0.0.0/0 (everything)

After that the rule named test just needs to be applied to a port:

console(config-if)# ip access-group test

Thats it, only ip packets matching this rule will be able to be transfered. Everything else will be dropped.

 

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